LL 11: Occupancy Effects on Air Infiltration

Occupancy Effects on Air Infiltration

#NO 10162 European indoor air quality audit project in 56 office buildings.
Bluyssen P M, de Oliveira Fernandes E, Groes L, et al
Indoor Air, No 6, 1996, pp 221-238, 14 figs, 8 tabs, refs.
Describes the European Indoor Air Quality Audit project, started in 1992 in which, in addition to current methods, trained sensory panels were used to investigate office buildings in several European countries. Its main aim was to develop assessment procedures and guidance on ventilation and source control, to help optimise energy use in buildings while assuring good indoor air quality. The selected buildings were studied while normally occupied and ventilated to identify the pollution sources in the spaces and to quantify the total pollution load caused by the occupants and their activities, as well as the ventilation systems. The paper presents results and conclusions in summary form only, based on a two-factor analysis. A further paper is planned.
#NO 10165 Implications of indoor climate control for comfort, energy and environment.
Mahdavi A, Kumar S
UK, Energy and Buildings, No 24, 1996, pp 167-177, 58 refs.
This paper critically examines the underlying premises of indoor climate control technologies and the HVAC industry (heating, ventilating,air conditioning). It questions whether 'total environmental control' is possible, effective and desirable. The paper also reviews the methods and terminology of thermal comfort science focusing on the question of predictability of people's environmental preferences. The paper concludes with a review of recent critical observations and ideas that transcend conventional control technologies and corresponding comfort standards towards new vistas in environmental design.
#NO 10175 The effect of contaminant source location on worker exposure in the near wake region.
Kulmala I, Saamanen A, Enbom S
Ann Occup Hyg, Vol 40, No 5, 1996, pp 511-523, 7 figs, refs.
The exposure of workers in the near-wake region due to a recirculating airflow was studied experimentally and numerically. A mannequin was installed in an open-ended tunnel and tracer gas was released at several locations downstream to determine the size and location of the reverse flow region. The contaminant transport into the breathing zone was found to depend strongly on the location of the release point. The airflow field was also determined numerically assuming a steady flow and using the standard k-epsilon turbulence model. After calculating the turbulent airflow field, a large number of submicrometre particles were released in different locations downstream of the mannequin to simulate the transport of gaseous contaminants. Although this method does not provide actual exposures, it does predict the tendencies in exposure variations due to different release points quite satisfactorily.
#NO 10178 Symptoms experienced, environmental factors and energy consumption in office buildings.
Lagoudi A, Loizidou M, Santamouris M, Asimakopoulos D
UK, Energy and Buildings, No 24, 1996, pp 237-243, 6 figs, 4 tabs, 24 refs.
A major increase of complaints has been observed by the occupants of buildings, concerning health symptoms and comfort. In this study, the occupants' experience of symptoms as well as the occupants' sensation of the environmental parameters were estimated in six office buildings, where the indoor air quality was investigated. It was found that the percentage of building related symptoms experienced by the occupants of the buildings was high and it was strongly related to human comfort and human sensation concerning the environmental conditions. The human response to the environmental conditions showed that none of the parameters was judged as being unacceptable overall, which indicates that the number of symptoms observed in each building cannot be attributed to one cause but to the contribution of various environmental parameters. Moreover, it was found that the increase in energy consumption was associated with the increase of health symptoms for these buildings.
#NO 10199 Radon in the workplace - a study of occupational exposure in BT underground structures.
Wiegand K, Dunne S P
Ann Occup Hyg, Vol 40, No 5, 1996, pp 569-581, 6 figs, 7 tabs, refs.
During the period August 1993 - October 1994 a study was undertaken throughout British Telecommunications plc to assess occupational exposure to radon. This paper is concerned only with that portion of the work concerned with underground structures. The results show that radon can build up to very high concentrations in manholes and implies a significant risk to those who need to work in them. For various reasons, which are explained, exposures are much less than predicted and in all but a very few cases the annual predicted radiation dose due to radon is expected to be below 5 milliSieverts (mSv). A safe system of work is described which seeks to ensure that no BT people receive an annual radiation dose of greater than 5 mSv as a result of occupational exposure to radon.
#NO 10201 Contribution of radon to overall exposure to radiation in a ten storey block building.
Mocsy I, Hunyadi I, Burkhardt R, Fulea C
Indoor and Built Environment, No 5, 1996, pp 241-244, 2 figs, 10 refs.
Radon is an inert radioactive gas released into the atmosphere from certain minerals and man-made products in which it is produced. It can accumulate in confined spaces. Radon emanation into a building can come from: the underlying soil, the building materials, tap water and natural gas. The principal isotope,222Rn, decays to products which if inhaled can result in exposure of the respiratory tract to alpha radiation. The decay products, radon daughters, are significant because of their potential to cause health effects. In this study we present measurements of radon concentration, and the internal and external gamma dose to which the inhabitants of a housing block with ten floors are exposed. Solid State Nuclear Track Detectors (CR-39) were used for the determination of radon concentration in the air. LiF (TLD-100) dosimeters were used for measuring the external gamma dose. Of the total equivalent dose to which people are exposed, it appears that from inside the building makes the greatest contribution.
#NO 10250 Personal exposure in displacement ventilated rooms.
Brohus H, Nielsen P V
Indoor Air, No 6, 1996, 157-167, 12 figs, refs.
Personal exposure in a displacement ventilated room is examined. The stratified flow and the considerable concentration gradients necessitate an improvement of the widely used fully mixing compartmental approach. The exposure of a seated and a standing person in proportion to the stratification of height is examined by means of full-scale measurements. A breathing thermal manikin is used to simulate a person. It is found that the flow in the boundary layer around a person is able to a great extent to entrain and transport air from below the breathing zone. In the case of non-passive, heated contaminant sources, this entrainment improves the indoor air quality. Measurements of exposure due to a passive contaminant source show a significant dependence on the flow field as well as on the contaminant source location. Poor system performance is found in the case of a passive contaminant released in the lower part of the room close to the occupant. A personal exposure model for displacement ventilated rooms is proposed. The model takes the influence of gradients and the human thermal boundary layer into account. Two new quantities describing the interaction between a person and the ventilation are defined.
#NO 10256 Calculation of the two dimensional airflow in facial regions and nasal cavity using an unstructured finite volume solver.
Davidson L, Nielsen P V
Denmark, Aalborg University, Dept of Building Technology and Structural Engineering, Indoor Environmental Technology Paper No 52, December 1995, 5 pp, 3 figs, 4 refs.
Demonstrates the feasibility of using computational fluid dynamics (CFD) for studying the flow in facial regions and nasal cavity. A two dimensional unstructured finite volume flow solver is used. For modelling the turbulence a standard k-epsilon model is used.
#NO 10284 Measured field performance and energy savings of occupancy sensors: three case studies. 
Floyd D B, Parker D S, Sherwin J R 
USA, Washington DC, American Council for an Energy Efficient Economy (ACEEE), Proceedings of the 1996 Summer Study on Energy Efficiency in Buildings, "Profiting from Energy Efficiency" 
Occupancy sensors have the potential to significantly reduce energy use by switching off electrical loads when a normally occupied area is vacated. While occupancy sensors can be used to control a variety of load types, their most popular use has been to control lighting in commercial buildings. Manufacturers claim savings of 15% to 85%, although there is little published research to support the magnitude or timing of reductions. Energy savings and performance are directly related to the total wattage of the load being controlled, effectiveness of the previous control method, occupancy patterns within the space and proper sensor commissioning. In an effort to measure performance, energy savings, and occupant acceptance, occupancy sensors were installed in a small office building and two elementary schools. 15-minute data was collected to assess performance. The three sites varied not only in size but also by occupancy patterns, occupant density, and the previous manual control strategies. Aggregate time-of-day lighting load profiles are compared before and after the installation and throughout the commissioning period when the sensors are tuned for optimum performance. For instance, savings on weekdays in the office building were less than 10% prior to the commissioning, although nearly doubled by proper tuning of the time delay setting and correcting false triggering problems. False ``ons'' during evening hours also affected savings. Occupant acceptance, sensor performance, and commissioning aspects are discussed as well as some recommendations for improved performance.
#NO 10285 Energy efficiency of occupant controlled heating, ventilating and air conditioning systems for office buildings. 
Glicksman L R, Taub S 
USA, Washington DC, American Council for an Energy Efficient Economy (ACEEE), Proceedings of the 1996 Summer Study on Energy Efficiency in Buildings, "Profiting from Energy Efficiency" 
Occupant controlled HVAC systems offer inhabitants of open office spaces some degree of control over their immediate microclimate typically by control of air supplied at floor or desk top level. Productivity gains have been attributed to these systems but it is unclear whether these systems will use less energy than conventional HVAC systems. It is also not clear what the controlling parameters will be. To study energy consumption, a simplified model of the thermal environment was created for an occupant controlled system. This model was combined with a model of the central HVAC plant and ambient weather conditions to simulate the annual energy usage for several climates. The HVAC control behavior of the occupants (e.g. comfort preferences) and the occupancy of each work station in the space were modeled as random processes. Factors affecting energy use are identified with this model. Typical occupant controlled systems are shown to offer HVAC savings of 5-16% depending on climate. Savings are achieved by occupancy sensors, properly selected plant and local supply temperatures, reduced cool air supply requirements due to thermal stratification, and reduced conditioning in areas which do not contain a workstation. The influence of occupant behavior, minimum temperature limits, local fan design and task lighting on energy savings is presented.
#NO 10290 Air conditioning in the Tropics: cool comfort or cultural conditioning? 
Agbemabiese L, Berko K, du Pont P 
USA, Washington DC, American Council for an Energy Efficient Economy (ACEEE), Proceedings of the 1996 Summer Study on Energy Efficiency in Buildings, "Profiting from Energy Efficiency" 
Since the combustion of fossil fuels is the leading causative factor in global climate change, the ``Western model'' of adopting energy-using technologies and using ever-greater amounts of energy will have important consequences for the future of human life on the planet if it is transferred on a wholesale basis to the developing world. It is thus important to try to understand, in the context of global development, the factors which drive the increased application of energy-using technologies, and whether there might be ways to satisfy human needs while limiting the environmental damage due to increased energy usage. This paper explores the rapid growth in the use of air conditioners in two tropical countries; Ghana and Thailand. We first assess the energy impacts and capital requirements of this coming wave of technology adoption. The rapid growth in the use of air conditioners will represent a challenge for policy makers in both countries, who at a minimum must implement policies to improve their efficiency. However, we present evidence from Ghana and Thailand_based on empirical studies as well as personal experience_ that air conditioners are often not necessary and may in many cases cause discomfort for tropical people who are not culturally conditioned to the technology. In addition, we discuss trends toward Western non-traditional dress, which reduces thermal comfort of people in the tropics and creates the need for mechanical cooling. We conclude with some suggestions for policies to promote alternative ways of keeping cool in the tropics, including building codes that encourage appropriate elements of traditional design, and dressing patterns that promote natural cooling.
#NO 10291 User satisfaction with innovative cooling retrofits in Sacramento public housing. 
Diamond R, Remus J, Vincent B 
USA, Washington DC, American Council for an Energy Efficient Economy (ACEEE), Proceedings of the 1996 Summer Study on Energy Efficiency in Buildings, "Profiting from Energy Efficiency" 
How do tenants of public housing respond to retrofits to improve their comfort and energy use during the cooling season? In contrast to retrofits to improve heating or lighting, cooling retrofits have been little studied, despite extensive programs by utilities and housing authorities to reduce this end use. A local utility and a housing authority have been retrofitting their buildings with evaporative coolers, ground-source heatpumps and other cooling measures. As part of an overall evaluation of the project we have conducted interviews with the residents, building managers and project staff to determine satisfaction with the performance of the systems. The initial evaluation revealed glaring defects in the design and installation of the systems, and not surprisingly, there was great dissatisfaction by the tenants and staff with their performance. Subsequent interventions and improvements to the equipment solved the technical problems, but tenant satisfaction was mixed. Further surveys revealed misunderstandings by the tenants on the nature of the evaporative coolers, their control and operation_often due to poor thermostat design_and expectations for comfort and familiarity with the technology. A significant finding from the study has been that despite the technical potential for these retrofit measures, the improper implementation of the systems, maintenance requirements and user behavior can all greatly impact the projected energy savings.
#NO 10292 How customers interpret and use comparative graphics of their energy use. 
Egan C, Kempton W, Eide A, et al 
USA, Washington DC, American Council for an Energy Efficient Economy (ACEEE), Proceedings of the 1996 Summer Study on Energy Efficiency in Buildings, "Profiting from Energy Efficiency" 
Comparative energy information is one method energy policymakers have employed to motivate consumers to reduce their energy use. The US appliance labeling program, for example, has used graphical displays to illustrate the differences in energy consumption among home appliances. Little is known, however, about how consumers interpret various graphical displays and/or how they use the information. Additionally, subtleties in the accuracy with which these graphical displays convey the underlying data have yet to be addressed in the research literature. This paper presents research on interpretation of graphical displays developed and tested by University of Delaware's Center for Energy and Environmental Policy under a cooperative agreement with the United States Environmental Protection Agency. The objective of the research is to provide utilities with tools that improve customers' ability to: (1) evaluate their energy use relative to others and (2) to measure the effects of their own efficiency efforts. Drawing upon the results of semi-structured interviews and a mail survey, we discuss the relative strengths and weaknesses associated with alternative display options. We have identified a number of problems with existing methods of presenting energy information in the areas of: (1) customer interpretations of the graphical displays and (2) their accuracy and reliability. We conclude with some suggestions as to how further research could address and overcome these problems.
#NO 10293 Energy and environmental awareness in Swedish and American households. 
Erickson R J 
USA, Washington DC, American Council for an Energy Efficient Economy (ACEEE), Proceedings of the 1996 Summer Study on Energy Efficiency in Buildings, "Profiting from Energy Efficiency" 
This paper compares energy and environmental awareness in two small towns in Sweden and Minnesota over time. In the early 1980s, Minnesotans were more anxious and exerted greater conservation efforts than the Swedes, but both are now bored with energy issues. They focus instead on environment_namely, recycling. Saving money continues to dominate decisions, but time is gaining priority in tradeoffs of energy, money, and time. Environmental concern is usually sacrificed to economics. Certain culturally-valued behaviors override both more conserving alternatives and economic considerations. Lacking the will to conserve, consumers say that they need, even wish for, some external authority to force them to do so. In general, consumers dislocate their personal activities from larger energy and environmental problems.
#NO 10303 Occupant satisfaction and environmental conditions following refurbishment of two air conditioned office buildings to natural ventilation. 
Booth W B, Williams R N 
UK, CIBSE, 1996, proceedings of CIBSE/ASHRAE Joint National Conference Part Two, held Harrogate, 29 September - 1 October 1996, Volume 1, pp305-314. 
Refurbishment is likely to be necessary in many of the existing air conditioned buildings. Converting to natural ventilation is one option for refurbishment which may reduce energy consumption. To explore possible problems, case studies have been carried out of two offices which have been monitored after refurbishment from air conditioning to natural ventilation. The site monitoring included measurements of a range of physical parameters in both the winter and summer seasons. These measurements were supplemented by post
#NO 10309 New trends in IAQ and ventilation. 
Bluyssen P M, de Oliveira Fernandes E 
UK, CIBSE, 1996, proceedings of CIBSE/ASHRAE Joint National Conference Part Two, held Harrogate, 29 September - 1 October 1996, Volume 2, pp 28-32. 
Fifty six office buildings in nine European countries were audited during the heating season of 1993-1994 using an agreed upon procedure to investigate the indoor air quality and energy consumption. The results of this IAQ-Audit project show that the largest indoor pollution sources in office buildings are construction materials, furnishings and indoor activities, immediately followed by the HVAC systems themselves. Thus, priority must be given to source control. A better knowledge of the pollution sources, in particular of those associated with materials and improperly designed and managed ventilation systems, is required. The results confirm that more ventilation tends to lead to better indoor air quality. However, it is also demonstrated that there are cases where more ventilation does not necessarily give the expected IAQ results. That means that more energy use may not necessarily lead to better indoor air quality.
#NO 10310 Integrated design for total indoor environmental quality. 
Levin H 
UK, CIBSE, 1996, proceedings of CIBSE/ASHRAE Joint National Conference Part Two, held Harrogate, 29 September - 1 October 1996, Volume 2, pp 33-38. 
Design for good indoor air quality IAQ) aims to prevent occupant discomfort, irritation, and illness. Sick building syndrome symptoms, discomfort and irritation can easily be the result of other, non-IAQ environmental variables. There is evidence that many such symptoms or complaints result from noise, poor lighting, lack of privacy or control, and other environmental factors that can cause these symptoms and complaints. It is important to identify the other critical environmental variables, to recognise relationships between them, and to make indoor environmental design decisions with full cognisance of the interdependent, dynamic relationships between all indoor environmental variables.. ASHRAE Guideline Project Committee IOP is developing "Criteria for Achieving Acceptable Indoor Environments," a document that will assist designers consider the total indoor environment.
#NO 10313 Conflicting criteria for thermal sensation within the Fanger Predicted Mean Vote Equation. 
Humphreys M A, Nicol J F 
UK, CIBSE, 1996, proceedings of CIBSE/ASHRAE Joint National Conference Part Two, held Harrogate, 29 September - 1 October 1996, Volume 2, pp 153-158. 
The PMV equation included in the PSV standard 7730 has become a common method for assessing the thermal environment in buildings. The equation employs different comfort criteria for estimating conditions which would yield thermal neutrality, and for assessing the effects of departures from neutrality. It is shown that this difference of criteria undermines the estimation of PMV whenever the clothing insulation differs from 0.6 clo, rendering the published tables inaccurate. The same weakness underlies the estimation of PPD (predicted percentage dissatisfied). Some examples of conflicting results are given, and an improved procedure is suggested.
#NO 10345 Flow and temperature fields around human body with various room air distribution. 
Murakami S, Kato S, Zeng J 
USA, Ashrae Transactions, Vol 103, Part 1, 1997, proceedings of the Ashrae Winter Meeting, Philadelphia, 25-29 January 1997. 
The ultimate aim of this study is to develop a computational thermal manikin which enables us to accurately predict the thermal comfort of a human in a room, by computer simulation. This paper describes the concept of the computational thermal manikin and its first stage development. Flow and temperature field around the human body have been investigated by modelling the thermal manikin with CFD. The convective heat transfer characteristics of the modelled manikin are predicted for several types of flowfield, i.e. stagnant flow, horizontal uniform flow, downward uniform flow, and upward uniform flow. The results agree well with previous experimental data.
#NO 10361 CFD analysis of thermal environment around human body.
Murakami S, Kato S, Zeng J
Japan, University of Tokyo, IIS Annual Report of Group Research Activity on Numerical Simulation of Turbulent Flows, No 11, 1996, pp 74-79, 5figs, 4 tabs, 11 refs.
Human's thermal sensation depends directly on heat transfer characteristics between human and his surrounding environment. These characteristics can be examined by numerical simulation of airflow,thermal radiation, heat conduction, moisture transport, solar radiation and so on in a coupled way. This paper describes the concept of computational thermal manikin. Flow and temperature fields around a human body have been investigated by modelling a thermal manikin with CFD (Computational Fluid Dynamics). The convective heat transfer characteristics of the modelled manikin are predicted for three types of flow field. The CFD simulations are conducted using a low-Reynolds-number k- E turbulence model in the generalized curvilinear coordinate system (Boundary Fitted Coordinates), so as to model the complicated shape of the human body. The obtained results agree well with previous experimental data.
#NO 10399 Energy efficiency in commercial and public sector offices.
Anon
UK, Department of the Environment, Energy Efficiency, Best Practice Programme, Energy Consumption Guide 19, 1996, 6pp.
Intends to encourage people responsible for the energy bills of office buildings to make energy cost savings. It allows comparisons to be made between the energy consumption and cost of the reader's building and yardsticks for typical and good practice offices. The information provided here is based on data collected from around 400 typical and best practice office buildings. Energy costs in these offices are usually 30-50% below average levels.
#NO 10434 Data for remedial measures against ventilation noise. Underlag foratgarder mot ventilationsbuller - vilka frekvensomraden av bredbandigtbuller ar minst och mest storande?
Landstrom U, Soderberg L, Nordstrom B, Kjellberg A
Sweden, Swedish National Institute for Working Life, Interim report No1995:13, 11pp, 8 figs, 2 tabs, refs.
20 subjects were exposed to a ventilation noise, and were given the possibility to adjust the mid frequency of a broad band component of the noise. The noise level was kept constant at 40 dBA. The frequencies given minimum and maximum annoyance were determined and were found to be134 and 456 Hz, respectively. The higher frequencies was associated with higher annoyance, discomfort as well as higher effort and lower self-reported performance in a proof reading task performed during exposure. The results show that lower broad band frequencies are less annoying the higher frequencies at the same dB(A) level. The dBA weighting thus may result in an overestimation of the annoyance caused by this type of low frequency components.
#NO 10435 Evaluation of tonal ventilation noise. Underlag for atgarder mot ventilationsbuller - vilka tonfrekvenser ar minst och mest storande?
Landstrom U, Soderberg L, Nordstrom B, Kjellberg A
Sweden, Swedish National Institute for Working Life, Interim Report No1995:14, 12pp, 8 figs, 2 tabs, 17 refs.
20 subjects were exposed to a tonal ventilation noise, with the information to adjust the tonal frequency at 40 dBA, to the lowest and highest annoying experiences. The adjusted frequencies were 58 and 380Hz. The higher performance was correlated to significant higher annoyance, discomfort and lower performance. The rate effort was higher but below the significant level of 5%. According to the investigation,lower tonal frequencies are less annoying the higher. The dBA latings thus may result in an overestimation of the annoying reactions in cases of tonal frequency components.
#NO 10436 Data for remedial measures against ventilation noise: the effect of fluctuations in level on perceived annoyance. Underlag for atgardermot ventilationsbuller - inverkan av nivafluktuationer pastorningsupplevelse.
Landstrom U, Soderberg L, Nordstrom B, Kjellberg A
Sweden, Swedish National Institute for Working Life, Interim Report No1995:29, 16pp, 12 figs, 4 tabs, refs.
Twelve subjects were exposed to simulated ventilation noises of varying character in a study of the effect on annoyance of level fluctuations which occurred above or partly below the threshold for hearing. The effect of the fluctuations was studied at constant sound levels or top levels. The sounds with the largest fluctuations were rated as most annoying. Sounds that passed the threshold for hearing in their fluctuations tended to be less annoying than those that always lay above the threshold. Annoyance was strengthened as the modulation frequency was raised from .5 to 2 Hz.
#NO 10437 Data for remedial measures against ventilation noise - the effect of constant relative bandwidths. Underlag for atgarder motventilationsbuller - effekten av konstanta relativa bandbredder.
Landstrom U, Soderberg L, Nordstrom B, Kjellberg A
Sweden, Swedish National Institute for Working Life, Interim Report No1995:34, 13pp, 7 figs, 1 tab, 7 refs.
24 subjects were exposed to four different sounds with the middle frequencies of 200, 300, 400 and 500 Hz at a level of 40 dB(A). The four sounds were made up by a tone and three sounds where the bandweight were kept constant over the four middle frequencies. For each sound the subjects rated their annoyance. The tonal exposures were considered more annoying than the broad band exposures. Among the three other bands, the largest was rated as more annoying than the two narrower bands. The 200 Hz sounds were rated as more annoying than the other frequencies for the tone and the narrowest band noise.
#NO 10444 Personal control systems still bring productivity gains.
Anon
USA, IEQ Strategies, April 1997, pp 10-12.
Outlines the operation of Johnson Controls' personal control workstations, which allow occupants to control air flow, temperature,under-desk heating, and to block some ambient noise.
#NO 10514 A field study of office thermal comfort using questionnaire software.
Newsham G, Tiller D K
USA, Ashrae Transactions, Vol 103, Part 2, 1997, proceedings of the Ashrae Summer Meeting, Boston, 29 June - 2 July, 1997 [preprint].
Custom software to automatically administer questionnaires on computer screens was installed on computers in four open plan offices. Five questions related to thermal comfort were presented twice per day for three months. Results indicate that this new method of subjective data collection was successful and efficient: the participants had few complaints about the method of questionnaire delivery; and a substantial literature review demonstrates that the results are comparable with results from other field studies of thermal comfort conducted using different methods.
#NO 10527 A thermal sensation prediction tool for use by the profession.
Fountain M, Huizenga C
USA, Ashrae Transactions, Vol 103, Part 2, 1997, proceedings of the Ashrae Summer Meeting, Boston, 29 June - 2 July, 1997 [preprint].
As a part of a recent Ashrae research project "Selecting and preparing a thermal sensation model for use by the profession", an MS Windows TM-based thermal sensation prediction tool has been developed. This paper introduces the tool, describes the component thermal sensation models, and presents examples of how the tool can be used in practice. Since the main end product of the HVAC industry is the comfort of occupants indoors, tools for predicting occupant thermal response can be an important asset to designers of indoor climate control systems. The software tool presented in this paper incorporates several existing models for predicting occupant comfort.
#NO 10531 Field study of occupant comfort and office thermal environments in a cold climate.
Donnini G, Molina J, Martello C, et al
USA, Ashrae Transactions, Vol 103, Part 2, 1997, proceedings of the Ashrae Summer Meeting, Boston, 29 June - 2 July, 1997 [preprint].
This paper presents the findings of ASHRAE research project RP-821, a field study of occupant comfort and office thermal environments in 12 mechanically ventilated office buildings in southern Quebec. A total of 877 subjects were surveyed during hot and cold months. Each interview provided a set of responses to a questionnaire and a set of physical indoor climatic measurements. The incremental effect of chairs was included in the estimates of clo values.
#NO 10551 Recommended ventilation strategies for new energy-efficient production homes.
Roberson J A, Matson N E, Brown R E, Koomey J G
UK, Air Infiltration and Ventilation Centre, proceedings of "Ventilation and Cooling", 18th Annual Conference, held Athens, Greece, 23-26 September 1997, Volume 1, pp 29-38.
The U.S. Environmental Protection Agency is seeking to improve the thermal quality of new homes, most of which are being built in the sunbelt by large building development companies. Low-infiltration production (tract) homes need ventilation systems that satisfy the low-cost priority of the builders as well as the safety, health and low operating cost expectations of homeowners. We evaluated ten ventilation strategies in order to recommend the most suitable systems for four climates: cold, mixed, hot-humid and hot-arid. We recommend that builders in mixed (cold and hot)' hot-humid and hot-acrid climates use supply ventilation, which provides the safety and health benefits of positive indoor pressure and the ability to filter and dehumidify ventilation air. When ventilation is integrated with forced-air conditioning, we recommend that ductwork be installed within conditioned space and buyers be offered the option of an efficient, variable speed fan. In cold climates we recommend that builders offer buyers the option of balanced heat recovery units, which significantly reduce operating costs. In hot-humid climates, we recommend that builders offer buyers the option of dehumidifying supply ventilation to control indoor humidity and improve occupant comfort.
#NO 10622 Evaluating and improving the environmental quality of building products with EQuity - some example applications.
Le Teno J F
France, Centre Scientifique et Technique du Batiment, proceedings of the Second International Conference on Buildings and the Environment, held Paris, June 9-12 1997, Volume 1, pp 257-264.
The EQuity model is a Life Cycle Assessment-based tool aimed at evaluating and improving building products Environmental Quality aspects. Unlike most "classical" LCAs, EQuity is strongly based on users' statements about their perception of environmental quality, as well as their goals and constraints pertaining to a given product study. Two applications of the EQuity model are presented in this paper. They illustrate the benefits of the case-by-case approach. Lessons drawn from these field-studies are detailed, and show that EQ can benefit from being integrated in all building products' life cycle steps.
#NO 10649 SEED Agenda 2000. Measurement based, "person centred" field data on the real building performance of public housing.
Walsh C J
France, Centre Scientifique et Technique du Batiment, proceedings of the Second International Conference on Buildings and the Environment, held Paris, June 9-12 1997, Volume 2, pp 445-453.
`SEED' Sustainable Energy-efficient Environment-friendly Development is a concept which has brought together for the first time three separate areas of concern and crystallizes the single idea that building energy performance cannot be evaluated in isolation from interrelated human and environmental factors. Allied to this working concept, the construction of a coherent philosophy, based on first principles are derived from interactive consultation with building users and the detailed observation / measurement of real building performance, has been a large factor in achieving effective results from a recent major study of public housing in Dublin, Ireland. This paper shows the resultant range / quality of the project observations and thermal comfort measurements in accordance with EN ISO 7730 : 1995 (1). Infra-red thermography (8 to 12 micron band) was of critical importance in understanding the real performance of each building and in suggesting new lines of investigation. Also illustrated are the results of an in-depth questionnaire survey with tenants on their own `comfort'. Finally, a strong linkage between energy efficiency, socio-economic status and health is demonstrated.
#NO 10652 Thermal and behavioural modelling of occupant-controlled heating, ventilating and air conditioning systems.
Glicksman L R, Taub S
UK, Energy and Buildings, No 25, 1997, pp 243-249, 10 figs, 1 tab, 21 refs.
Occupant-controlled heating, ventilating and air conditioning (HVAC) systems allow inhabitants of open-plan spaces some degree of control over their immediate microclimate. Typically, cooled air is supplied at floor or desktop levels. The amount and direction of air flow is under occupant control. Productivity increases have been attributed to this form of control. This paper proposes a simplified model of the thermal environment created by an occupant-controlled HVAC system and the behaviour of the occupants within it. The thermal environment is characterized by individual nodes representing sub-areas of the conditioned space and a single well-mixed ceiling space above the occupied zone. Random processes are used to simulate the comings and goings of individual occupants and their HVAC control behaviour. The model is used to identify the parameters which have the largest influence on the energy efficiency. Energy use of task HVAC with occupant sensors is found to be less than that of a conventional HVAC system by 13%. Individual HVAC control requires about 10% more energy than uniform temperature conditions.
#NO 10661 Low-energy local authority housing with reduced construction costs.
Energy Efficiency Office
UK, Energy Efficiency Office, May 1989, Energy Efficiency Demonstration Scheme, Expanded Project Profile 245, 4pp, 4 figs.
Describes a demonstration project whose aim was to show that two storey, low-energy housing when combined with a simplified heating system can be constructed at lower cost than housing equipped with conventional central heating. Ten houses on a new low-energy development were each fitted with a simplified gas-fired whole house heating system. The design allowed warm air generated by two heating appliances to migrate to all parts of the house, including the upstairs rooms which were not directly heated. Monitoring, including surveys of the occupants, confirmed that the simplified heating system operated satisfactorily with a small (13%) additional energy saving.
#NO 10676 CIBSE/ASHRAE joint national conference part 2, Volume 2.
CIBSE
UK, Chartered Institution of Building Services Engineers, CIBSE, 1996, proceedings of a conference held Harrogate, UK, 29 September - 1 October 1996, Volume 2, 412pp.
Volume 2 of the proceedings covers buildings and health; historic buildings; cooling; environment; building automation; user perception; maintenance; comfort; feedback; software; and poster papers.
#NO 10723 The effects of human behaviour on natural ventilation rate and indoor air environment in summer - a field study in southern Japan.
Iwashita G, Akasaka H
UK, Energy and Buildings, No 25, 1997, pp 195-205, 10 figs, 10 tabs, 5 refs.
Residents completed a questionnaire survey assessing indoor environment and residents' behaviour (i.e. when they opened windows/doors, when they operated air conditioners, and so on) during the period of ventilation measurement. The purpose of this study is to measure the ventilation rate in occupied dwellings in Kagoshima City, located in the southern part of Japan, using the tracer gas method and to investigate the relationship between the occupants' behaviour in each dwelling and the energy consumption for air conditioning during the summer period. Based on the continuous measurement of the ventilation rate in eight dwellings, the proportion between the total ventilation rate (ventilation rate during occupancy of the dwellings) and the basic ventilation rate (ventilation rate during non-occupancy and with door/windows closed) is discussed. The measuring principle applied is the constant tracer gas method. The main conclusion is that there is a large difference between the mean basic ventilation rate and the mean total ventilation rate. If the size of the basic ventilation rate and the user-influenced ventilation rate in the investigated dwellings are compared, it can be seen that 87% of the total air change rate is caused by the behaviour of the occupants.
#NO 10843 Comfort and control in the workplace.
Lomonaco C, Miller D
USA, Ashrae Journal, September 1997, pp 50-56, 7 tabs, 25 refs.
Analyses various studies on worker comfort to state that the physical environment can have a measurable impact on worker productivity of about 3% to 15%. Also discusses the importance of individual control especially as it relates to diverse responses to environmental conditions. The ERW (environmentally responsive workstation) provides workers with complete control over such conditions as airflow, filtration, temperature, lighting and acoustics. Finds that updating HVAC systems, retrofitting lighting, offering flexible workstations, finding ways to dampen noise levels all on a system wide basis will generally help increase levels of productivity. The West Bend study demonstrates that the "experts", i.e. the individual, increase their productivity when in control of their own environment.
#NO 10850 John Cabot City Technology College.
Standeven M, Cohen R, Bordass B, Leaman A
UK, Building Services Journal, October 1997, pp 37-42, 3 figs, 4 refs.
Post occupancy report on a new college building. Assesses building design, ventilation performance, daylighting and shading, lighting and controls, central plant controls, energy and water consumption, facilities management, and occupancy issues.
#NO 10891 Passively cooled and ventilated learning resource centre: performance appraisal.
Robinson D
UK, Building Serv Eng Res Technol, Vol 18, No 3, 1997, pp 129-139, 10 figs, 7 tabs, 15 refs.
A quasi-automatic system has been developed to monitor the energy and environmental performance of a new university learning resource centre. The centre is a THERMIE demonstration project. Monitoring has concentrated on global performance indicators, to describe envelope and environmental provision effectiveness; Micro-performance indicators, to describe performance at the zonal level and ancillary performance indicators, to describe the performance of parameters which cannot be sensed automatically. The effectiveness of the building in reducing energy consumption and providing a pleasant internal environment has been quantified in both physical and psychological terms. Results suggest that, when designing similar buildings in future, greater attention should be paid to humidification, distributing daylight, and the provision and thorough commissioning of appropriate automatic and manual occupant controls.
#NO 10945 Results from field testing of a presence controlled ventilation system in an occupied office building.
Ducarme D, Wouters P, L'Heureux D
Belgium, Proceedings of Clima 2000 Conference, held Brussels, August 30th to September 2nd 1997, paper 333, 9pp, 9 figs, 2 refs.
The use of IR detectors to steer the ventilation is in principle an attractive approach for optimising the ventilation according to the occupants needs. In order to evaluate the performances under real conditions, one of the BBRI office buildings in Limelette (some 31 offices with in total 51 persons and a variable occupation load) was equipped with a mechanical supply ventilation system in which each terminal is controlled by an IR detector. During a two week period, the performances of the ventilation system were measured in detail (total air flow rate, functioning of each individual terminal, pressure control function, energy consumption, acoustical measurements,...). The paper presents first the concept of the ventilation system and some of the measured performances at component level. The overall performance of the system is then discussed as well as the impact of the building and ductwork airtightness. Finally conclusions and recommendations for further improvements are given.
#NO 10950 Effect of airflow direction on human perception of draught.
Toftum J, Zhou G, Melikov A
Belgium, Proceedings of Clima 2000 Conference, held Brussels, August 30th to September 2nd 1997, paper 366, 7 figs, 1 tab, refs.
Forty subjects, 20 women and 20 men, were exposed to airflows from five different directions: horizontally towards the front, the back, and the left side and vertically upwards and downwards. The subjects were exposed to stepwise increased air velocities ranging from less than 0.10 m/s to 0.40 m/s at three temperature levels 20, 23 and 26oC. The results showed that airflow direction has an impact on perceived discomfort due to draught. At 20oC and 23oC, airflow from below was perceived as most uncomfortable followed by airflows towards the back and front. At 26oC airflow from above and towards the back caused most dissatisfaction due to draught, but generally only a few of the subjects perceived discomfort at this temperature. Discomfort due to draught was most often felt at the body regions directly exposed to the airflow. These were the legs, the feet, and the lower back at airflow from below; the neck, the shoulders and the hands at airflow from above; the neck, the back, the shoulders and the legs at airflow from behind; the knee and the arm facing the windbox when exposed to air movements directed towards the side; and the hands and the knees when exposed to air movements towards the front.
#NO 10989 Do sunspaces work in Scotland? Lessons learnt from a CEC solar energy demonstration project in Glasgow.
Porteous C D A, Ho H M
Int. J. Amb. Energy, Vol 18, No 1, 1997, pp 23-35, 11 tabs, refs.
The paper examines the extent to which users' intervention may compromise the thermal performance of small sunspaces in the context of a Solar Energy Demonstration Project at Easthall in Glasgow which was monitored from September 1992 to May 1994. Results indicate a tendency to close down windows etc. late in autumn and open them up early in spring relative to heat demand. In other words a user-driven energy load due to ventilation is higher in autumn and spring than in the central winter period. However, effective rate of ventilation, taking account of the preheat effect of the glazed spaces, is found to be more steady over an entire heating season. Thus, inclusion of glazed buffers has been shown to lessen the thermal burden of window opening in autumn and spring; while saving in winter due to preheated air for ventilation tends to be slightly higher than predicted. Results also indicate that amount and frequency of opening/ventilation relates to specific social and occupancy characteristics; and that some users were able to trim their energy load by better use of the controls at their disposal in the second season. As a by-product, the monitoring has shown that energy models which take a steady rate of ventilation over a heating season are unrealistic.
#NO 11029 Simulating people moving in displacement ventilated rooms.
Mattson M, Bjorn E, Sandberg M, Nielsen P V
USA, Washington DC, Healthy Buildings/IAQ '97, 1997, proceedings of a conference held Bethesda MD, USA, September 27 - October 2, 1997, Volume 1, pp 495-500, 6 figs, 9 refs.
A displacement ventilation system works better the more uni-directional the air flow through the ventilated room is: from floor to ceiling. Thus, from an air quality point of view, there should be as little vertical mixing of the room air as possible. It is therefore comprehensible that physical activity in the room - like peoples movements - has been shown to influence the effectiveness of the ventilation. In this study we have compared results from previous tests, where a cylindrical person simulator was used, to results obtained when using a person simulator of more human like shape. The main results verify previous findings: of the movements are not very slow, they have a detrimental effect on ventilation effectiveness and on the air quality in the breathing zone of the inhabitants. Some quantitative differences were found between using the simple and the detailed person simulator, although the qualitative results were about the same.
#NO 11035 Control of occupant-generated indoor air sources in small buildings through ventilation system retrofit.
Bayer C W, Fischer J
USA, Washington DC, Healthy Buildings/IAQ '97, 1997, proceedings of a conference held Bethesda MD, USA, September 27 - October 2, 1997, Volume 2, pp 77-82, 4 figs, 6 refs.
A research study was undertaken investigating a retro-fit ventilation system a strategic ventilation to provide a better indoor environment to smaller buildings. A residential type HVAC unit interfaced with a desiccant energy wheel was retro-fitted into the ventilation system of a small office space built into a warehouse. The primary objective of this study was to minimize environmental tobacco smoke transfer from smokers offices to nonsmokers offices via the application of strategic ventilation.
#NO 11041 Displacement ventilation - effects of movement and exhalation.
Bjorn E, Mattson M, Sandberg M, Nielsen P V
USA, Washington DC, Healthy Buildings/IAQ '97, 1997, proceedings of a conference held Bethesda MD, USA, September 27 - October 2, 1997, Volume 2, pp 163-168, 9 figs, 9 refs.
Full-scale experiments were made in a displacement ventilated room with two breathing thermal manikin to study the effect of movements and breathing of the vertical contaminant distribution, and on the personal exposure of the occupants. Concentrations were measured with tracer gas equipment in the room and in the inhalation of both manikins. Trace gas was added in the heat plume above the sitting manikin, or in the exhalation through either the nose or the mouth. The other manikin moved back and forth at different speeds on a low trolley. The mentioned experimental conditions have a significant influence on contaminant distributions and personal exposures.
#NO 11043 Task conditioning + displacement ventilation, 1+1>2?
Loomans M G L C, Rutten P G S
USA, Washington DC, Healthy Buildings/IAQ '97, 1997, proceedings of a conference held Bethesda MD, USA, September 27 - October 2, 1997, Volume 2, pp 305-310, 7 figs, 2 tabs, 14 refs.
After a brief introduction of the desk displacement ventilation concept, which combines displacement ventilation with task air conditioning ,this paper describes the experimental set-up and preliminary results if full scale measurements and Computational Fluid Dynamics (CFD) simulations for an office configuration in which the concept is applied. Results are used to discuss the concept on micro/macro-climate and parameters as thermal comfort and cooling load. Main conclusion is that the separation between micro and macro climate, as is a characteristic of task conditioning, is less pronounced and may require improvement of the concept. Experimental and numerical results show differences when standard wall functions are applied in the turbulence model. Incorporation of measured heat transfer coefficient as one of the boundary conditions leads to a better agreement with the experimental results and affords a more reliable application of CFD for evaluation purposes.
#NO 11062 Interaction of air motion with the human body.
Myers J B, Hosni M H, Jones B W
USA, Ashrae Transactions, Vol 104, Pt 1, 1998, 20pp, 14 figs, 3 tabs, refs.
Proper distribution of conditioned air plays a major role in both human thermal comfort and indoor air quality. The objectives if this study were (1) to experimentally evaluate airflow conditions around the human body and (2) to characterise the interaction of the thermal plume from the body with the overall room air motion. Environmental conditions around the human body were examined by mapping temperature and velocity distributions around a thermal manikin using modern temperature and velocity instrumentation in an environmental chamber. Results are presented for three test cases: baseline velocity and temperature distribution without manikin, airflow blockage of the unheated manikin and mixed convection due to interaction of chamber airflow with the heated manikin. Air movement data collected near the thermal manikin demonstrate both the blockage effect of and thermal plumes from the thermal manikin. The unheated thermal manikin exhibited a localised blockage effect to a distance of 0.15m (6in.) behind the manikin. The velocity and temperature boundary layer of the thermal manikin expanded further from the body in the mixed convection case than in the unheated blockage case. Near the manikin skin surface, the velocity distribution for the mixed convection was primarily dependent on the room air motion and the blockage effect of the manikin and was independent of natural convective effects. The temperature boundary layer was substantially influenced by natural convection below chest level, while at and above chest level, the temperature distribution was affected by room air motion, the blockage effect, and the heating of the manikin. The total power to the heated thermal manikin was set at 164W (561Btu/h), to represent a person with a modest activity level (1.5 met). The distribution of the heat loss over the surface of the manikin was determined by the manikin's heaters and to a reasonable approximation, represents the head distribution of a person.
#NO 11066 Statistical analysis of unsolicited thermal sensation complaints in commercial buildings.
Federspiel C C
USA, Ashrae Transactions, Vol 104, Pt 1, 1998, 11pp, 12 figs, 10 tabs, refs.
Unsolicited complaints from 23,500 occupants in 690 commercial buildings were examined with regard to absolute and relative frequency of complaints, temperatures at which thermal sensation complaints (too hot or too cold) occurred, and response times and actions. The analysis shows that thermal sensation complaints are the single most common complaint of any type and that they are the overwhelming majority of environmental complaints. The analysis indicates that thermal sensations complaints are mostly the result of pool control performance and HVAC system faults rather than inter-individual differences in preferred temperatures. The analysis also shows that the "neutral" temperature in summer is greater than in the winter and the difference between summer and winter "neutral" temperatures is smaller than the difference between the midpoints of the summer and winter ASHRAE comfort zones. In average, women complain that it is cold at a higher temperature than men and the temperature at which men complain that it is hot is more variable than for women. Analysis of response times and actions provides information that may be useful for designing a dispatching policy, at it also demonstrates that there is a potential to reduce the labor cost of HVAC maintenance by 20% by reducing the frequency of thermal sensation complaints.
#NO 11088 Relationships between the indoor environment and productivity: a literature review.
Sensharma N P, Woods J E, Goodwin A K
USA, Ashrae Transactions, Vol 104, Pt 1, 1998, 16pp, 2 figs, 4 tabs, refs.
Results of studies assessing the relationship between indoor environmental quality and productivity are often divergent. Additionally, these results provide little direction to design and construction professionals for achieving environmental quality that supports occupant performance and productivity. The objective of this literature review was to identify commonly used measures of productivity and their links with factors in the indoor environment related to HVAC system performance. This literature research identified 262 references, 53 of which were found to be relevant in addressing these issues. As a means to analysing the results reported in the literature, measures of productivity were classified in terms of traditional and nontraditional figures of merit (FOMs). It was found that office environments are the primary focus of current research and that most studies do not address the wide range of factors that may influence productivity. Additionally, contradicting results were found regarding the relationship between human responses, occupant performance, and productivity. It is concluded from these results that FOMs can be standardised for specific building functional categories (BFCs) but that site-specific modifications may be needed. To identify FOMs that are measurable and controllable, it is important to identify links between occupant performance and productivity and a set of factors including systems, exposures, and human responses. It is recommended that future research focus on defining reliable and valid FOMs, standardising FOMs for each BFC and clarifying the links in human responses, occupant performance and productivity.
#NO 11098 Field study of the impact of a desktop task/ambient conditioning system in office buildings.
Bauman F S, Carter T G, Baughman A V, Arens E A
USA, Ashrae Transactions, Vol 104, Pt 1, 1998, 19pp, 11 figs, 6 tabs, refs.
A field study was carried out to assess the impact of installing a desktop task/ambient conditioning (TAC) system at 42 selected workstation within three San Francisco office buildings occupied by a large financial institution. In this study, field measurements, including subjective surveys and physical monitoring were performed both before and after the TAC system installation to evaluate the impact of the TAC system on occupant satisfaction and thermal comfort, as well as the thermal environments within the office buildings. For comparative purposed within each building, a control group consisting of workers who did not receive and desktop TAC unit, was studies concurrently. During the follow up field tests, performed three months after the TAC system installation, measurements were repeated under three different room temperature setpoint conditions (normal set-up and set-down) to investigate the ability of the occupants to use the desktop TAC units to control their local environment in response to a wider range or ambient temperatures. Survey results show that among the six building assessment categories investigate, installation of the desktop TAC system provided the largest increases in overall occupant satisfaction for thermal quality, acoustical quality and air quality. In terms of specific environmental factors, increased occupant satisfaction levels among the TAC group were strongly significant in comparison to changes within the control group for both temperature and temperature control. A large majority of the workers in the control group indicated a preference for higher air movement at operative temperatures of 73oF (23oC) and above. The percentage preferring higher air movement with the TAC group was significantly lower. Workers in the TAC group had the ability to use their TAC units to adjust the air movement in their workstations in response to changes in the ambient temperature. Over the range of operative temperatures covered by this field study, air movement preference and thermal sensation votes by workers in the control group indicated that they were more than twice as sensitive to changes in temperature than those in the TAC group.
#NO 11114 Probe: some lessons learned from the first eight buildings.
Bordass W, Bunn R, Cohen R, Standeven M, Leaman A
UK, Chartered Institution of Building Services Engineers, 1997, proceedings of CIBSE National Conference held Alexandra Palace, London, UK, 5-7 October 1997, Volume 1, pp 7-16, 2 figs, 2 tabs, 14 refs.
Eight published post occupancy surveys have focused on building services and energy performance, management and occupant satisfaction in buildings of technical interest. All the buildings are relatively good; and two of them had unusually high occupant satisfaction: a sophisticated deep-plan air conditioned office which demanded (and received) a high level of management; and a simple, low energy, largely naturally-ventilated medical centre, in which occupants were prepared to forgive some of the inefficiencies in lighting, ventilation and summertime temperatures. Very good energy performance was delivered in three of the naturally-ventilated buildings, but in the more advanced of them, difficulties with control, commissioning, usability and management - problems which also afflict air-conditioned buildings - had affected occupant satisfaction. The results indicate the need for better briefing; more recognition and discussion of the demands buildings are likely to make on their occupants and management; more robust and sometimes simpler solutions with downside risks considered and minimised; intrinsically efficient systems with more usable controls and feedback; and better industry support to occupiers after handover.
#NO 11123 Modern ventilation techniques - the indoor environment and occupant perception.
Williams R N, Booth W B, Kirby L
UK, Chartered Institution of Building Services Engineers, 1997, proceedings of CIBSE National Conference held Alexandra Palace, London, UK, 5-7 October 1997, Volume 1, pp 206-226, 16 figs, 9 tabs, 6 refs.
In recent years there has been a gradual re-emergence of the use of passive or "low energy" ventilation and cooling techniques including mixed mode application. It is apparent that many clients, developers and agents are reluctant to make a commitment to such "low energy" buildings due to concerns, albeit unsubstantiated by hard evidence, that such buildings will provide acceptable comfort levels for occupants. The project included the measured assessment of three buildings which utilise these modern "low energy" ventilation techniques, evaluating the internal environment performance with particular reference to occupant comfort and perception. The monitoring was carried out in both the winter and summer seasons on a zonal basis using both long and short term logging techniques. BRE/RSH style questionnaires were also used in both seasons with the personal well-being questions asked only during the winter monitoring. The results of the three larger buildings are given relating the measured environmental parameters to the occupants' perception of their environment.
#NO 11124 Occupant satisfaction with environmental conditions in naturally ventilated and air conditioned offices.
Oseland N A, Brown D K, Aizlewood C E
UK, Chartered Institution of Building Services Engineers, 1997, proceedings of CIBSE National Conference held Alexandra Palace, London, UK, 5-7 October 1997, Volume 1, pp 227-135, 10 figs, 3 tabs, 10 refs.
During the past three years, BRE has conducted winter and summer occupant surveys on satisfaction with environmental conditions in 23 buildings. These were a mixture of naturally ventilated and air conditioned buildings. The results presented in this paper are based on a secondary analysis of 5136 completed questionnaires. The aim of the analysis was to determine the effect of ventilation type and season on occupant satisfaction with key environmental parameters: thermal sensation, thermal comfort, humidity, air movement, stuffiness, air quality, lighting and noise. Although 3% more occupants were satisfied with the environment in air conditioned offices than in naturally ventilated ones, this difference does not justify the 60% extra energy consumption and the additional installation and maintenance costs associated with the air conditioned offices.
#NO 11172 Investigating the use of displacement ventilation in large meeting rooms. Untersuchung zum Einsatz von Quelluftanlagen in grossen Versammlungsraeumen.
Maennel J, Hoffmann M
Germany, HLH, Vol 48, No 12, 1997, pp 38-42, 9 figs, 1 tab, 5 refs.
Notes that large meeting rooms with strongly differing usage are not the preferred domain for displacement ventilation since free three-dimensional flows affect the supply air distribution. Describes laboratory investigations and investigations carried out in a lecture theatre and a concert hall under conditions of differing degrees of occupancy and concludes that the existing displacement ventilation model can in principle be applied to rooms with high rates of heat release. Makes recommendations for calculating the correct location of the displacement air diffusers and their influence on the overall room flow.
#NO 11198 Displacement ventilation - effects of movement and exhalation.
Bjorn E, Mattsson M, Sandberg M, Nielsen P V
proc of "Healthy Buildings '97", 5th International Conference on Healthy Buildings, September 27-October 3, 1997, Washington DC, USA, 6pp, 9 figs, 9 refs.
Full-scale experiments were made in a displacement ventilated room with two breathing thermal manikins to study the effect of movements and breathing on the vertical contaminant distribution, and on the personal exposure of occupants. Concentrations were measured with tracer gas equipment in the room and in the inhalation of both manikins. Tracer gas was added in the heat plume above a sitting manikin, or in the exhalation through either the nose or the mouth. The mentioned experimental conditions have a significant influence on contaminant distributions and personal exposures.
#NO 11199 CFD models of persons evaluated by full scale wind channel experiments.
Brohus H, Nielsen P V
Proceedings of ROOMVENT '96, Fifth International Conference on Air Distribution in Rooms, Yokohama, Japan, July 17-19, 1996, Vol 2, pp 137-144, 6 figs, refs.
This paper presents three different CFD models of a person. The models are discussed and evaluated by comparison with full-scale measurements comprising a breathing thermal manikin standing in a wind channel. The three CFD models are made in a rectangular geometry. The most simple one is a heated cuboid with the same surface area and heat flux as a human being. The most complex one also includes "legs" and "head". The models are evaluated in a steady-state CFD simulation of personal exposure to a contaminant source in a uniform velocity field. It is found that the models of a person are capable of simulating the important main features in the flow around a person. In all cases the simulated exposure approaches the same order of magnitude as the measured exposure. It is also found that inclusion of "legs" in the model might improve the result, especially when the contaminant source is located close to the floor.
#NO 11244 Online outdoor air flow control by estimating occupancy.
Wang S, Jin X
Air conditioning in high rise buildings '97, proceedings of international symposium, September 1997, Shanghai, International Institute of Refrigeration, Vol 1, pp 126-131, 12 figs, 5 refs.
This paper presents a dynamic method to estimate the actual occupancy in indoor space by measuring the carbon dioxide concentration of return air and outdoor air flow rate. The accuracy and response speed are tested and compared with the steady-state estimating method under various occupancy profiles. An on-line outdoor air control strategy using dynamic estimating method and the validation of the method are presented. The indoor air quality and energy performance of demanded ventilation using these strategies are evaluated under various indoor occupancy and outdoor weather conditions.
#NO 11250 Personal exposure to contaminant sources in ventilated rooms.
Brohus H
Denmark, Aalborg University, Department of Building Technology and Structural Engineering, Doctoral Thesis, December 1997, 264pp.
Exposure models usually treat the indoor environment as well-mixed compartments without concentration gradients. However, in practice concentration gradients will occur, for instance, in the vicinity of contaminant sources or in the case of displacement ventilation. When a person is located in a room where concentration gradients prevail, the local concentration distribution may be changed significantly and thus the personal exposure. Three different tools for personal exposure assessment are presented. They are all able to consider the local influence of persons in ventilated rooms where concentration gradients prevail: - the Breathing Thermal Manikin - the Computer Simulated Person - The Trained Sensory Panel The tools are applied on the two major room ventilation principles, namely the displacement principle and the mixing principle. This is done in order to examine the tools and to investigate how the exposure assessment is influenced when concentration gradients and persons are considered. A personal exposure model for a displacement ventilated room is proposed. Two new quantities describing the interaction between a person and the ventilation are defined. The findings clearly stress the need for an improved exposure assessment in cases where a contaminant source is located in the vicinity of persons. It is also shown that it is not sufficient to know the local concentration level of an empty room, the local impact of a person is distinct and should be considered in the exposure assessment.
#NO 11260 Enthalpy and perceived air quality - a paradigm shift.
Fanger P O
Germany, Heiz. Luft. Haustech., Vol 48, No 11, November 1997, pp 8,10, 1 fig, 5 refs.
Argues that the impact of indoor air humidity on people has been neglected for decades, since humidity in the comfort temperature band has a minor effect on the thermal sensation of the entire human body. In addition, ventilation rates required to obtain a certain perceived air quality have also been assumed to be independent of humidity. The thinking has been that pollutants generated indoors need to be diluted with outdoor air to a level perceived to be acceptable. Refers to new studies at the Technical University of Denmark showing that perceived air quality is also strongly influenced by the temperature and humidity of the inhaled air. People like a sensation of cooling of the respiratory tract each time air is inhaled. Illustrates in a diagram perceived air quality (and acceptability) as a function of the enthalpy of air polluted by typical building materials. Sets out measures which will improve perceived air quality or make possible reduced rates of ventilation by lowering the enthalpy of the indoor air.
#NO 11264 A Uniclima reception guide on mechanical ventilation systems in collective dwellings. Guide de reception Uniclima des installations de ventilation mecanique en logements collectifs.
Moysan B
France, CVC, April 1998, pp 29-32.
Ventilation in dwellings needs to provide healthy air to occupants, to protect the building envelope from unwanted condensation and to help clear specific pollutants. Occupants' lack of understanding of the objectives does little to help promote the public image of ventilation. Poor quality of building envelope tightness can also lead to malfunctions in exhaust ventilation systems. Since ventilation professionals have little influence on these two points, regulations must be responsible for changing attitudes. Describes how Uniclima and UCF have worked to develop an exhaust system precontrol method for fitters.
#NO 11391 Perceived air quality and ventilation requirements at higher latitudes.
Fanger P O, Fang L, Tanabe S
Iceland, ICEVAC, The Icelandic Heating, Ventilating and Sanitary Association, Proceedings of the Cold Climate HVAC '97 Conference, held in Reykjavik, Iceland, April 30-May 3, 1997, pp 25-35, 6 figs, 1 tab, 40 refs.
Over the last two hundred years, dramatic paradigm shifts have taken place in the philosophy behind ventilation. Why are we ventilating buildings and how much ventilation is required? These are the fundamental questions with which engineers, architects and hygienists are faced. The paper will review the thinking behind the very different answers that have been given to these questions in the past. Models used in new ventilation standards in progress will also be discussed, including the addition of sensory pollution sources, the acknowledgement of building materials and ETS as pollution sources, and the impact of filtration, temperature and humidity on required ventilation. Special attention is given to humidity and temperature at higher latitudes. Comprehensive future changes in HVAC technology are foreseen, involving a paradigm shift where indoor air designed not only to be acceptable and to limit dissatisfaction, but also to be perceived as pleasant, fresh and stimulating.
#NO 11407 Sick building syndrome and psychosocial factors - a literature review.
Lahtinen M, Huuhtanen P, Reijula K
Indoor Air 1998, Suppl. 4, pp 71-80, 2 tabs, refs.
Sick building syndrome (SBS) with an unknown etiology has led researchers to focus on the role of psychosocial factors in the work environment as well as on individual characteristics in SBS. Recent research has suggested that psychosocial factors are quite strongly associated with SBS. The associations have been confirmed in buildings that were beforehand considered to be problem cases, and also in buildings whose condition was not known in advance. However, SBS symptoms could not be attributed to psychosocial factors alone. Most of the previous studied have supported the conclusion that SBS most likely is of a multifactorial origin related to chemical, physical, biological and psychosocial factors that interact or coincide with one another. Unfortunately, for the time being, it is not possible to characterise adequately the relationship between the various risk factors and the possible mechanisms of SBS. There is an urgent need for more empirical research, especially follow-up studies and interventions, for development of the methodology and for new theory-building in order to better understand the relations between environmental factors, personal factors and the symptoms of SBS. In this literature review, SBS is viewed from an occupational stress perspective.
#NO 11410 Discomfort caused by odorants and irritants in the air.
Fanger P O
Indoor Air, 1998, Suppl 4, pp 81-86, 4 figs, 1 tab, refs.
Why are we ventilating buildings and how much ventilation is required? These are the fundamental questions that engineers, architects and hygienists have tried to answer over the past two hundred years. Dramatic changes in the philosophy behind ventilation have occurred but during the last half century, buildings have been ventilated primarily to avoid discomfort caused by odorants and irritants in the air, i.e. to establish an indoor air quality that is perceived acceptable for humans. This philosophy is still behind ventilation standards at present being revised in different parts of the world, although health effects are also being considered. The historical development will be briefly reviewed and common new trends in the revisions of European and American standards will be discussed. New data on the additivity of sensory pollution sources and on the impact of temperature and humidity will be reviewed. A new paradigm shift in the philosophy behind ventilation is predicted.
#NO 11411 The ethics of using human panels in the indoor air sciences.
Molhave L
Indoor Air, 1998, Suppl. 4, pp 87-95, refs.
The Helsinki Declaration and similar national regulations require that the ethical aspects of all intended experimental exposures of humans should be evaluated and found acceptable, using the best available toxicological principles and data. In the low-level exposure ranges of indoor air, very little is known about the principles for such evaluations and few health data exist. This paper discusses principles for such evaluations in relation to experimental exposures of IAQ panels. The acceptability of chemical exposures of human subjects in IAQ research should be based on the following principles. a) Only reversible non-adverse health effects can be accepted. The risk of adverse effects associated with exposure must be documented to be acceptably low. b) Exposures to well-known chemicals or emissions from commercially available sources can be accepted if these sources have a history of many years' problem-free use on the free market and if their use during the experimental exposures corresponds to normally encountered exposures. Studies including exceptional exposures or sensitive subjects should be registered and evaluated by the local ethics committees. c) Exposures to emissions from new types of source can be accepted if the exposures are chemically identified and are below official, indoor, outdoor or occupational guidelines for exposures. Procedures for the evaluation of exposures to compounds lacking toxicological data are discussed. These exposures should be registered and evaluated by local ethics committees. d) The selection of subjects must include special pre-tests and defined exclusion criteria to exclude risk groups.
#NO 11412 Influence of different indoor activities on the indoor particulate levels in residential buildings.
Chao C Y H, Tung T C W, Burnett J
Indoor and Built Environment, No 7, 1998, pp 110-121, 9 figs, 2 tabs, 17 refs.
This study reports 24-hour measurements of indoor particulate levels in 8 residential premises in Hong Kong. The 24-hour respirable suspended particulate (RSP) levels varied from 44.9 to 119.4 ug.m-3 and the corresponding total suspended particulate (TSP) levels varied from 45.8 to 122.2 ug.m-3. These levels are higher than those measured in other countries. This was found to be related to the poor quality of outdoor air found in Hong Kong and also to the different indoor activities practised by these families. During the measurements indoor activities were recorded and ventilation rates at some of the sites were also measured using the carbon dioxide decay technique. A significant rise of particulate level was detected during cooking, smoking and burning of incense. In the study, particulate levels over 5,000 ug.m-3 were observed during some cooking activities. Particulate levels when people were smoking were 2-3 times higher than the relative background level. Incense burning in some families produced a peak concentration of particulates around 2,000 ug.m-3 if the ventilation was poor. The effect of rain was to wash the outdoor particulates from the air and at the same time the indoor particulate level fell if the ventilation rate was high enough. It was observed that about 20% of the indoor dust level could be reduced in less than 1 h when there was heavy rain. It was also found in the study that a very high indoor RSP to TSP ratio of 82-98% existed indoors.
#NO 11428 Modelling people.
Riordan P
UK, Building Performance, No 1, Spring 1998, pp 14-15, 2 figs, 3 tabs.
Describes results of work on occupants' heating and cooling behaviour in temperate climates. Explains the difficulties of building simulation in relation to occupant behaviour. The underlying assumption in most thermal simulations is that building occupants seek "thermal comfort". These assumptions have a crucial effect on energy consumption predictions and design messages. Key facts about occupant behaviour are observed. People have a variety of ways of dealing with being too hot or cold, and thermal neutrality is not necessarily the desired state: they apparently often alter controls in order to feel the change. Results of a survey are tabulated.
#NO 11429 A study of occupant cooling by personally controlled air movement.
Arens E, Xu T, Miura K, et al
UK, Energy and Buildings, No 27, 1998, pp 45-59, 11 figs, 4 tabs, 23 refs.
This study addresses the effectiveness of air movement cooling, an alternative to compressor-based cooling of the air itself. Subjects in an environmental chamber were exposed to a range of warm temperatures and allowed to adjust air movement to suit their individual preferences, while answering a series of questions about their comfort. Air movement was from the subject's side, in two modes of turbulent flow. The air speeds chosen by the subjects, and their subjective responses, are evaluated in the context of existing comfort standards and prediction techniques. Choosing air speeds up to 1.4 m/s, over 80% of subjects at 1.2 met were comfortable up to 29 Deg C, and at 1.0 met up to 31 Deg C. The cooling effectiveness was significantly affected by the nature of the turbulence. A zone is proposed within which personally controlled air movement provides a likely alternative to mechanical air conditioning.
#NO 11454 Probe 14: Elizabeth Fry building.
Probe Team
UK, Building Services Journal, April 1998, pp 37-42, 3 figs, 5 refs.
Examines how one of the first buildings in the UK to use the Termodeck mechanical ventilation system and various other Swedish detailing has fared. The building is an academic facility at the University of East Anglia. A report by BRECSU, the result of detailed monitoring of the building's energy and environmental performance between January 1996 and August 1997 is due shortly. An occupant survey was conducted among office staff. Scores were very high for overall comfort, winter and summer air quality and lighting, and a lower than benchmark number of occupants were dissatisfied with the lack of control over heating.
#NO 11472 Occupant interaction with a mixed media thermal climate control system improves comfort and saves energy.
Rowe D M, Forwood B, Dinh C T , Julian W G
Morocco, Marrakesh, ITEEC 1997, proceedings of ITEEC 97 International Thermal Energy and Environment Congress, held 9-12 June 1997, Marrakesh, Morocco, pp 568-573, 6 figs, 6 refs.
Occupants of a suite of seven offices intervene to adjust their thermal environments by manipulation of ventilation through doors and windows and by operation of supplementary cooling and heating equipment when considered necessary. Intervention actions, space temperatures and energy consumption have been monitored continuously for twelve months. Energy simulation models have been used to compare the energy consumption with an estimate of what might be expected with a conventional ducted air conditioning system for the same space. It is reported that the recorded energy consumption is approximately one quarter of that estimated for the alternative system. Occupants rate the space highly for satisfaction with the thermal environment and air quality.
#NO 11497 Case Study on Prevalence and Possible Causes of Sick Building Syndrome Symptoms
Taki A H, Moore T
Sweden, Stockholm, KTH Building Services Engineering, 1998, proceedings of Roomvent 98: 6th International Conference on Air Distribution in Rooms, held June 14-17 1998 in Stockholm, Sweden, edited by Elisabeth Mundt and Tor-Goran Malmstrom, Volume 1, pp 155-162.
Offices are assumed to be more healthy places to work in than factories and thus problems with occupational health ought to be minimal. However, many maladies can be attributed to the modern office environment, to include legionnaires disease, Pontiac fever, humidifier fever and one for which as yet no specific cause has been identified i.e. Sick Building Syndrome (SBS). This paper assesses the prevalence and nature of symptoms of building sickness, together with possible causation of these symptoms. Incidence of SBS symptoms involving 36 occupants in their own offices were investigated in a naturally ventilated building based in Leicester, UK. Furthermore, an objective study was undertaken to include the measurements of the environmental variables within the space offices. The level of symptoms was found to be significant and strongly correlated with air temperature, stuffiness, odourless, air quality, noise and overall thermal comfort. The results suggest that indoor air pollution can be the prime causal agent behind symptoms, where source of the pollution is from within building materials. High level of dry eye symptoms was strongly associated with dust; headache symptoms were linked with noise level; and blocked nose with higher air temperatures. Air temperatures were strongly correlated with symptoms while ventilation rates were not found to be contributory factors. In addition, other possible causes for SBS symptoms are discussed.
#NO 11511 Study on Thermal Comfort of Task-Ambient Air Conditioning System
Nakamura Y, Mizuno M, Ueno O, Sekimoto Y, Akagi K, Mishima N, Otaka K, Kohyama M
Sweden, Stockholm, KTH Building Services Engineering, 1998, proceedings of Roomvent 98: 6th International Conference on Air Distribution in Rooms, held June 14-17 1998 in Stockholm, Sweden, edited by Elisabeth Mundt and Tor-Goran Malmstrom, Volume 1, pp 257-264.
Task-ambient air conditioning system is one of the systems developed to achieve quality indoor thermal environment and energy conservation simultaneously. The purpose of this study is to find the optimum supply air conditions of floor air outlet required to make thermally comfortable environment in the task area without cold draft. To achieve the purpose were carried out the experiments with subjects, who were allowed to control the supply air volume and the direction of inclined jet according to their tastes. The main results are as follows: the suitable combination of the room air temperature and the supply air temperature is 28_C-20_C under which thermally comfortable environment is created in the task area without cold draft. And the subjects have a tendency to use positively the cooling effect of the air flow by leading the jet to their bodies no matter whether the jet hits them directly or indirectly.
#NO 11557 Comparison of IAQ performances of French ventilation systems in residential buildings.
Millet J R, Villenave J G
UK, Air Infiltration and Ventilation Centre, proceedings of "Ventilation Technologies in Urban Areas", 19th Annual Conference, held Oslo, Norway, 28-30 September 1998, pp 233-241.
Until now, there is no widely accepted way to express any index for this purpose and taking into account the large variety of possible pollutants. Things can be simplified if the aim is more to compare different systems and strategies than to give an absolute value of quality. For the study of a pollutant source, the main important point for comparison is the pattern of its production, whatever this pollutant is. For human feeling and health we defined 5 main generic pollutants: constant emission related to the room area; human metabolism (using CO2 as a tracer); emission due to cooking activities; passive smoking; indoor humidity related to the dryness feeling. The detailed data is for each inhabitant the curve of the number of hours above a pollutant level concentration Ci : Nh (Ci). A condensed one is calculated as the cumulated value above a threshold limit Cimax. This is the basis for the results presented here. Other parameters are also calculated as pressure difference between outdoor and indoor, room related parameters (humidity, condensation, hazards), and energy parameters (heat needs and fan energy). This methodology was defined and used in the framework of IEA annex 27 "domestic ventilation". The main ventilation systems used in France have been described based on the Ann27 approach, applied by using the ventilation code SIREN, developed by CSTB. The sensitivity analysis presented in the paper takes into account different climates, dwelling types, airtightnesses, dwelling occupancies, water vapour production.
#NO 11563 Building performance evaluation for indoor air quality using occupant contaminant inhalation and attribution to contaminant sources.
Takemasa Y, Moser A
UK, Air Infiltration and Ventilation Centre, proceedings of "Ventilation Technologies in Urban Areas", 19th Annual Conference, held Oslo, Norway, 28-30 September 1998, pp 293-304.
The emissions of building materials like volatile organic compounds and indoor airborne contaminants such as environmental tobacco smoke expose occupants to hazardous substances. Although impacts of indoor air quality problems on human health, comfort, and productivity are quite large, no adequate evaluation methodology exists to assess contaminant source control techniques and building equipment systems. Even if instant indoor concentrations of many contaminants are not always high, continuous exposures to these contaminants may cause severe problems such as manifested by the sick building syndrome.
This paper proposes a method for evaluating long-term building performance in terms of indoor air quality. The approach applies exposure assessment but focuses on building performance. It employs the concept of using the total amount of substance inhaled by persons who occupy the room. This indicator is expressed by kilograms of each contaminant inhaled by persons ever present in the building during its operational life. The values include the effects of occupant rates. Concrete procedures for deriving variations of the indicators for both gaseous and particulate contaminants are described in detail. Another concept of contribution rates of contaminant sources is introduced both for instant values and on the inhalation basis. Evaluation examples of these indicators for a simple office geometry are shown for particulate matter, carbon dioxide, and formaldehyde. The results of the case studies strongly suggest the importance of indoor material selection and ventilation strategies. The contribution rate of contaminant sources makes it easier to plan a remedy for bad indoor air quality. The applicability of these indicators and future research requirements are also discussed.
#NO 11564 Improvement of indoor climate and ventilation system in a renovated multistoried residential building.
Palonen J
UK, Air Infiltration and Ventilation Centre, proceedings of "Ventilation Technologies in Urban Areas", 19th Annual Conference, held Oslo, Norway, 28-30 September 1998, pp 305-313.
The goal of this project was to improve the quality of indoor air in a multistoried residential building of 81 flats built in 1960. The building is located in a heavily built urban area of Helsinki. The building had a mechanical exhaust ventilation system without outdoor air inlets. A questionnaire was sent to occupants and a condition survey was made prior to renovation. The main indoor climate problem was draught with a prevalence of 60%. Other almost as common problems were traffic noise also during nights and dust coming from the street. The ventilation system was fully unbalanced with reduced exhaust air flows partly due to uncleaned exhaust air vents. A new type of fresh air window with air filtration (EU 5) and good acoustic performance was developed. The sound insulation value measured in field was 42 dB(A). When these new windows were installed in the dwellings a new questionnaire was sent to occupants. The results showed clear improvement in all indoor climate related factors. The habitants were much more satisfied with the performance of ventilation system after the renovation measures.
#NO 11567 Displacement ventilation in a classroom - influence of contaminant positioning and physical activity.
Mattsson M
UK, Air Infiltration and Ventilation Centre, proceedings of "Ventilation Technologies in Urban Areas", 19th Annual Conference, held Oslo, Norway, 28-30 September 1998, pp 333-341.
This study describes how the air quality in a displacement ventilated classroom can be influenced by the position of a contaminating person, and by the activity of a person who walks around in the room. Tracer gas measurements have been performed in a full scale mock-up of a classroom, with person simulators at the students' desks.
The spreading of contaminants from a person seems to be strongly dependent on the position of the person. The closer the contaminating person sits to the outlet terminal(s), the less of his/her contaminants are spread in the room. Paradoxically, people sitting furthest away from the air supply were found to be provided with the least contaminated air. Physical activity, produced by a walking person, tends to increase the concentration of contaminants emitted from people in the room, whereas the air exchange efficiency actually can benefit from it. At all levels of activity tested in this study the displacement ventilation system provided significantly better air quality than a mixing system would.
#NO 11579 Modern passive stack and ventilated schools - evaluation of ventilation and moisture conditions.
Blomsterberg A, Sikander E, Ruud S
UK, Air Infiltration and Ventilation Centre, proceedings of "Ventilation Technologies in Urban Areas", 19th Annual Conference, held Oslo, Norway, 28-30 September 1998, pp 450-457.
The aim has been to determine ventilation rates and risk of moisture damage in three modern schools with passive stack ventilation. The users are supposed to control the ventilation by using the lantern windows and the outdoor air is assumed to enter through an underground duct. The paper presents results, analysis and conclusions from the performed measurements and calculations. The ventilation rates are sometimes low and vary with the use of the windows in the facade and the lantern. It is, however, always possible to arrive at a sufficient ventilation rate. The supply air flow through the underground duct can, without a supply fan, be low and even go backwards during warm weather. To obtain desired ventilation rates and energy conservation the building must have a good airtightness. High relative humidities and even periods with condensation occur in the underground supply duct during spring and summer. Microbial growth has been found in two of the schools. Two important factors are choice of material and cleaning, where the knowledge is insufficient today. Moisture and microbial growth have been found in the roofs. The leakage paths, supply of moisture indoors and an interior pressurisation have contributed. In order to reduce the risks the building must have a good level of airtightness.
#NO 11592 Nitrogen dioxide levels in homes in Avon, England.
Coward S K D, Raw G J
in: Healthy Buildings '95, an international conference on healthy buildings in mild climate, Milano 10-14 September 1995, proceedings, volume 1, pp 379-384, 3 tabs, 7 refs.
A survey of nitrogen dioxide (NO2) levels in homes has been carried out by the Building Research Establishment (BRE) as part of the Bristol University "Avon Longitudinal Study of Pregnancy and Childhood (ALSPAC)". This paper describes the background, method and simple descriptive statistics to show what NO2 concentrations were found. Bivariate and multivariate analysis were also carried out to identify associations between NO2 concentrations and possible determinants (e.g. the presence of a gas cooker); all but the most basic of those results are given in a companion paper.
In ALSPAC, women are recruited in early pregnancy, and the health of the children will be monitored for seven years from birth. The county of Avon was considered suitable for the English study because it has a mixture of urban and rural areas, varied industry, and a population which is demographically representative of the rest of Britain. To be eligible for the study, subjects had to be resident in the study area while pregnant and have an expected date of delivery between 1 April 1991 and 31 December 1992. Approximately 14,000 women entered the English study.
BRE conducted the "ALSPAC Indoor Environment Study" which was a survey or air quality in 174 homes of participants in the main study. Approximately ten women were recruited each month from November 1990 until March 1992, from a list of volunteers supplied to BRE by Bristol University. Participants completed initial and post-natal questionnaires, and up to twelve monthly updates on their homes and activities. The initial questionnaires were completed in conjunction with the placing of samplers to detect levels of NO2 and other pollutants inside and immediately outside the home. This paper is concerned only with results for NO2.
#NO 11606 Laboratory simulation of human bioeffluents sources using carbon dioxide as a tracer gas.
Auger M R, Farant J P
Canada, Concordia University Centre for Building Studies, 1995, Indoor air quality ventilation and energy conservation in buildings. 2nd International Conference, volume 2, pp239-246, 4 figs, 1 tab, 6 refs.
An experimental setup is presented that can measure concentrations generated around a pulsating source of carbon dioxide (CO2) that simulates human respiration. The experimental setup is used to study the relationship between the ventilation efficiency and the pollutant removal efficiency of a space. These are two key parameters which describe the ability of a space in providing a comfortable and healthy environment for its occupants. Preliminary results obtained so far have focused on the conditions inside a small test chamber. Some preliminary results are presented after a discussion on current tracer gas techniques used in the field.
#NO 11644 Rules for cooling through motorized vent windows.
van Paassen A H C, van Galen P J M
Netherlands, Apeldoorn, in: proceedings of the 19th International Congress of Refrigeration, Den Haag 20-25 Aug, 1995, pp 1089-1096.
Describes an investigation carried out in Japan into how people use the various possibilities to influence their environment, such as opening the window, switching on the air conditioning unit, use the sunshading and so an. The results revealed that most people would open windows first and switch on air conditioning last. The so called "passive climate system" has been designed with this tendency and the necessity to save energy in mind. Goes on to describe the new system in full. The passive components are: sunshading awning; high and low placed windows, motorized and automatically controlled together with the active components. Active components are: the radiator or air conditioning unit; the lighting. Sensor are: indoor air temperature; sensor detecting the presence of people; weather station on top of the building, measuring windspeed, wind-direction, outdoor temperature and solar radiation.
#NO 11685 Natural ventilation and automation with manual overriding are health solution.
van Paassen A H C, Lute P J
TVVL-REHVA Symposium: Healthy Buildings in Relation to Building Services, 17-21 February 1992, Utrecht, The Netherlands, pp 79-92, 8 figs, 1 tab, refs.
The need for individual control with manual overriding combined with controlled natural ventilation is discussed. It is made plausible that with these two facilities problems related with the Sick Building Syndrome can be avoided.
This principle is applied in a so-called passive climate system. A system is devised setting the level of heating and ventilation by controlling motors fitted to radiators, ventilation openings in window, Venetian blinds and outside shading. Moreover, it will switch on the lighting when natural lighting is inadequate. The system comprises a weather station on the roof, a network of sensors and controllers in each room hooked up to a control computer. The room controllers can be overridden manually by the occupants.
With computer simulations it has been demonstrated that through nocturnal air cooling with opened windows and predictive control a comfortable indoor climate can be realised year round, provided that the internal load lies between 15 and 20 W/m2. Higher loads require additional mechanical cooling. Moreover, it is shown that a proper combination of controlled natural ventilation and mechanical cooling leads to an enormous reduction in energy consumption. It can be reduced to 20% of the amount that is normally required in buildings with closed facades. Moreover, the capacity of the cooling room unit can be reduced with 50%. The ability to remove internal heat and the costs of the passive climate system is compared with that of more conventional systems. It has been shown that the passive system is very promising and that the option with the additional cooling unit is superior to all the other systems.
#NO 11690 Impact of temperature and humidity on the perception of indoor air quality.
Fang L, Clausen G, Fanger P O
Indoor Air, No 8, 1998, pp 80-90, 7 figs, refs.
Sensory responses to clean air and air polluted by five building materials under different combinations of temperature and humidity in the ranges 18-28oC and 30-70%RH were studied in the laboratory. A specially designed test system was built and a set of experiments was designed to observe separately the impact of temperature and humidity on the perception of air quality/odour intensity, and on the emission of pollutants from the materials. This paper reports on the impact on perception. The odour intensity of air did not change significantly with temperature and humidity; however, a strong and significant impact of temperature and humidity on the perception of air quality was found. The air was perceived as less acceptable with increasing temperature and humidity. This impact decreased with an increasing level of air pollution. Significant linear correlations were found between acceptability and enthalpy of the air at all pollution levels tested, and a linear model was established to describe the dependence of perceived air quality on temperature and humidity at different pollution levels.
#NO 11691 Zusammenhang zwischen Empfundener Luftqualitaet und Prozentsatz Unzufriedener. Relationship between perceived air quality and percentage of dissatisfaction.
Spiess T
Germany, HLH, Vol 49, No 7, July 1998, pp 69-71, 3 figs, 2 tabs, 13 refs.
Describes developments in Fanger's procedure for measuring indoor air quality as a result of studies undertaken at the Hermann-Rietschel-Institut. They have shown that good to excellent air quality can be obtained, and continue to compare perceived air quality and percentage dissatisfied.
#NO 11695 The influence of human activity on the vertical distribution of airborne particle concentration in confined environments: preliminary results.
Micallef A, Caldwell J, Colls J J
Indoor Air, No 8, 1998, pp 131-136, 6 figs.
Vertical concentration profiles for various size fractions or airborne particulate matter have been measured in a non-smoking indoor environment used mainly as a meeting point during coffee break (11.00 am) and tea time (4.00 pm). This monitoring exercise was carried out using a novel sampling system specifically designed for measuring concentration gradients of airborne particles (but which can be easily modified for gaseous pollutants) over the first three metres from ground. The results show substantial gradients in concentration, with the highest occurring at around 1.3 m height. A plausible explanation for the measured time series of concentration at different levels from ground, and the vertical distribution of concentration, is thought to be human movement and activity in the confined environment. The implications that the results of this experiment have for indoor air quality standards for airborne particulate matter are discussed.
#NO 11775 The environmental protection agency's research program on total human exposure.
Ott W, Wallace L, Mage D, et al
Environment International, Vol 12, 1986, pp 475-494, 6 figs, 2 tabs, refs.
The U.S. Environmental Protection Agency's (U.S. EPA) research program on total human exposure to environmental pollution seeks to develop a newly emerging concept in the environmental sciences. Instead of focusing purely on the sources of pollution or their transport and movement through the environment, this research focuses on human beings as the receptors of these pollutants. People and daily activities become the center of attention. The methodology measures and models the pollutant concentrations found at the physical boundaries of people, regardless of whether the pollutants arrive through the air, water, food, or skin. It seeks to characterize quantitatively the impact of pollution on people by determining if an environmental problem exists at the human interface and, if so, by determining the new sources, nature, extent, and severity of this environmental problem. By exploiting an emerging new arsenal of miniaturized instruments and by developing statistically representative survey designs for sampling the population of cities, significant progress has been made in recent years in providing previously unavailable human exposure field data needed for making valid risk assessments. The U.S. EPA total human exposure research program includes: development of measurement methods and instruments, development of exposure models and statistical protocols, microenvironmental field studies, total human exposure studies, validation of human exposure models with empirical data, and dosage research investigations.
#NO 11788 Indoor air quality and the use of energy in buildings.
Baldwin R (ed.)
Luxembourg: Office for Official Publications of the European Communities, 1996, EUR 16367 - European collaborative action 'Indoor air quality and its impact on man': Indoor Air Quality and the Use of Energy in Buildings, Environment and quality of life series, 68 pp, 3 figs, 7 tabs, ISBN 92 827 6347 1.
This report provides information and advice to policy and decision makers, researchers, architects, designers, and manufacturers on (i) strategies for achieving a satisfactory balance between good indoor quality air (IAQ) and the rational use of energy, (ii) guidelines on the use of energy in buildings and IAQ currently available, (iii) significant trends in the building sector with implications for IAQ and energy use and (iv) current research concerns.
The report discussed the relationships and potential conflicts between the IAQ and the efficient use of energy in buildings and related factors such as the influence of occupancy and occupant activities, energy use and sustainability, indoor air pollution and its control, and health and comfort aspects of indoor air quality and climate. The influence of climatic conditions and their variations across Europe on IAQ and energy use, socio-economic costs of poor IAQ and its relation to the use of energy and trends for the future in the building sector are also briefly addressed. Current research concerns in the field of IAQ and energy use in buildings are highlighted and gaps in knowledge and research needs are identified.
Key elements of a strategy by which designers, engineers, manufacturers and other decision makers can achieve a good balance between energy use in buildings and indoor air quality (IAQ) are proposed. Following the recommended procedure will reduce the risk of poor IAQ and waste of energy.
#NO 11789 Energieeinsparung durch Wohnungslueftungsanlagen? Energy conservation by ventilation systems for dwellings?
Hartmann T, Oschatz B, Richter W
Germany, Ki Luft- und Kaeltetechnik, No 12, 1998, pp 562-568, 8 figs, 18 refs, in German
Building tightness, ventilation behaviour of the inhabitants and the system air changes have an important influence on the energy requirement of buildings. Under the conditions of today no energy conservation in relation to free ventilation (window ventilation) can be obtained by the application of mechanical ventilation systems. Only the optimization of the total system "ventilation system + heating system + buildings" as well as an adapted ventilation behaviour of the users enable the development of energy saving potentials.
#NO 11790 Energy audits.
Anon
USA, Home Energy, July/August, 1998, pp 22-24, 4 figs.
Describes a project carried out by Massachusetts Division of Energy Resources to find out if its home energy audit program was effective. A survey carried out found that customers wanted the audits, but that few were using the results to improve energy efficiency in their homes. The project concluded that by installing only 16% of the recommended measures (and tending to install the cheaper measures), customers had realized only 10% of potential energy savings from the audit recommendations.
#NO 11794 Impact of psycho-social factors on perception of the indoor air environment studies in 12 office buildings.
Haghighat F, Donnini G
UK, Building and Environment, No 34, 1999, pp 479-503, 14 figs, 7 tabs, 11 refs.
The main function of a mechanically ventilated office building is to provide a healthy and comfortable working environment for occupants, while maintaining minimum energy consumption. Twelve mechanically ventilated buildings were selected. They varied greatly in surface area, number of floors, occupant density, and building use. The indoor air quality, thermal comfort, energy consumption, and perception of occupants were investigated in these buildings. A total of 877 subjects participated in the questionnaire survey during the hot summer months of June, July and August, and during the cold winter months of January, February, and March. The questions included in the questionnaire dealt with health, environmental sensitivity, work area satisfaction, personal control and the workstation's environment, and job satisfaction. Measured parameters concerning the quality of indoor air included ventilation rate, concentration of TVOC, CO2, CO, RH, and formaldehyde. The thermal comfort parameters included room air, mean radiant, plane radiant asymmetry, and dew point temperatures, as well as air velocity and turbulence intensity. Monthly energy consumption data was also gathered for each building. Ventilation performance, in terms of air flow rate and indoor air quality, was compared with the ASHRAE Standard 62-89R (Ventilation for Acceptable Indoor Air Quality, Atlanta: American Society of Heating, Refrigerating, and Air Conditioning Engineers, Inc. U.S.A. [1]). The measured and calculated thermal environmental results were also compared with the ASHRAE Standard 55-92 (Thermal Environmental Conditions for Human Occupancy, Atlanta: American Society of Heating, Refrigerating, and Air Conditioning Engineers, Inc. U.S.A. [2]). CO2 and CO levels satisfied the recommended limits. The outdoor airflow rate was half that recommended in only one building. The formaldehyde and TVOC levels were moderately higher than suggested comfort levels. However, more that 56% of the occupants rated dissatisfaction with the indoor air quality. Only 63% of the indoor climatic observations fell within the ASHRAE Standard 55-92 summer comfort zone; 27% in the winter. However, only 69% of those surveyed agreed with the comfort zones. More symptoms were reported by workers who perceived IAQ to be poor. Positive relationships were observed between the job satisfaction and satisfaction with office air quality, ventilation, work area temperature, and ratings of work area environment. However, job dissatisfaction did not correlate with symptom reports. The occupants were more dissatisfied with IAQ when they preferred more air movement. In other words, the higher the perceived air movement, the greater the satisfaction with IAQ.
#NO 11800 Determination of exposure-response relationships for emissions from building products. 
Knudsen H N, Valbjorn O, Nielsen P A
Denmark, Indoor Air, No 8, 1998, pp 264-275, 9 figs, 1 tab, refs.
Building products have been shown to affect the perceived indoor air quality in buildings. Consequently, there is a need for characterizing the emissions from building products in sensory terms to evaluate their impact on the perceived air quality. Determining the exposure-response relationship between concentration of the emission from a building product and human response is recommended. A practical method is proposed based on an air-dilution system connected to the exhaust of a ventilated small-scale test chamber. The method was used to determine the exposure-response relationships for eight building products. For each building product, samples were placed in a test chamber. A typical room was used as a reference to calculate a building-realistic area-specific ventilation rate in the test chamber. A sensory panel assessed the immediate acceptability of polluted air at four different concentrations 3, 10 and 29 days after samples of the building products were placed in the test chambers. The exposure-response relationships show that the impact of dilution of polluted air on the perceived air quality varies between building products. For some building products it may only be possible in practice to improve the perceived air quality marginally by increasing dilution. The results of the present study suggest that for such building products, source control is recommended as the remedy for poor indoor air quality, rather than an increase of the ventilation rate.
#NO 11842 The simulation of adaptable components in the external envelope of a building.
Van Loeij J, Mollaert M
UK, James & James Ltd, 1988, proceedings of "Environmentally friendly cities", PLEA 98 (Passive and Low Energy Architecture) conference, held Lisbon, Portugal, June 1998, pp 341-344, 18 figs, 2 tabs, 9 refs.
This paper considers the building's envelope in the design phase. Energy related decisions during the design phase have great influence on the life cycle cost of the building. 
Since sunlight and climate are changing factors, the envelope is equipped with mobile and adaptable components (shading devices, movable insulation, opening window schedules ...) which can react to climatic conditions.
Architects use computer aided design tools to describe a building and its envelope. A lot of objects and parameters for the heating, cooling, lighting, ventilation and acoustic simulations during the design process are already specified in the architect's computer model of the building.
With a few test cases the data exchange between the architect's software tool (e.g. AutoCAD, Speedikon) and the building physics software for the different application fields (Trnsys, ESP-r, Radiance, Raynoise ...) is analysed.
The main goal is to obtain a good performance for each of the mentioned disciplines. Several simulations are performed to evaluate the effect and the sensitivity of the adaptable components (changes from season to season, or from day to night) on the efficiency of the building.
Based on these studies a conceptual data model can be presented to support integrated studies in the preliminary design stage.
#NO 11850 Using night cooling in a temperate climate.
Nicol F, Robinson P, Kessler M R
UK, James & James Ltd, 1988, proceedings of "Environmentally friendly cities", PLEA 98 (Passive and Low Energy Architecture) conference, held Lisbon, Portugal, June 1998, pp 467-470, 3 figs, 10 refs.
In 1993, the Open University in Milton Keynes, UK, refurbished the open-plan first floor Design Studio in their Publishing Department to use natural ventilation to keep the interior cool. At the same time the third floor, which was not suitable for passive cooling, was fitted with mechanical comfort cooling units and the intermediate floor was not changed. This paper compares the thermal performance of the three floors and discusses the results of a staff-satisfaction survey conducted among the occupants. It shows that despite conditions being cooler on the third floor in the very hottest weather, the passively cooled floor was preferred overall. Lessons can be drawn for the successful use of passive cooling in temperate climates.
#NO 11893 Architecture for intelligent thermostats that learn from occupants' behaviour.
Boisvert A, Rubio R G
USA, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc (ASHRAE), 1999, in: the ASHRAE Transactions CD, proceedings of the 1999 ASHRAE Winter Meeting, held Chicago, USA, January 1999, 7 pp, 8 figs, 2 tabs, refs. 
This paper proposes a new approach to thermostat design. For many years, thermostats have been "dumb" devices, meaning that they react to their environment either by direct user control or by previous user programming. This new approach details an intelligent thermostat that learns about the behaviour of the occupants and their environment and controls ambient temperature to maintain comfort according to human specifications. In that way, the thermostat reduces the number of interactions with the user and eliminates the need for them to learn how to program the device. Additionally, the thermostat reduces energy consumption by setback when occupants are absent, While the proposed architecture fundamentally changes the functionality of today's conventional thermostats, it retains their simple user interface.
This article presents the modular software architecture of this new intelligent thermostat design. The functionality of the thermostat in different states is described and how each module specializes in learning a certain pattern is explained. At the end, the results obtained using neural networks as a technique for learning are presented.
#NO 11954 Thermal plumes above a person.
Hyldgaard C E
Sweden, Stockholm, KTH Building Services Engineering, 1998, proceedings of Roomvent 98: 6th International Conference on Air Distribution in Rooms, held June 14-17 1998 in Stockholm, Sweden, edited by Elisabeth Mundt and Tor-Goran Malmstrom, Volume 1, pp 407-413, 11 figs, refs.
Comprehensive air velocity measurements were carried out above a thermal manikin to find the velocity distribution in the plume above the head. The thermal manikin was either standing or sitting in a climate room (6 x 8 x 4.6m) in quiet, isothermal surroundings. The air velocities in the plume were measured at different heights above the top of the head. The manikin's heat effect was varied within a wide range. The measurements were made with both a breathing and a non-breathing manikin. The velocities were measured by means of a flow analyser equipped with 24 hot ball probes mounted on a measuring cross. The measurements were complemented with measurements made with a Laser-Doppler anemometer.
#NO 12010 A two compartment model for determining the contribution of sources, surface deposition and resuspension to air and surface dust concentration levels in occupied rooms.
Schneider T, Kildeso J, Breum N O
UK, Building and Environment, No 34, 1999, pp 583-595, 6 figs, 4 tabs, 48 refs.
A semi-empirical two-compartment, constant parameter model is used to predict airborne and surface dust concentrations. The model parameters are air in- and exfiltration, internal particle sources, surface deposition caused by settling, Brownian and turbulent diffusion and thermophoresis, track-in of dust particles and resuspension. Model predictions are calculated for some typical scenarios, and the soiling rate of a vertical surface is calculated for a range of friction velocities and electric field strengths. Model sensitivity is determined based on input parameter value distributions for a population of rooms estimated from published data. The predictions are sensitive to track-in and resuspension rates on which field data thus are needed.
#NO 12064 Analysis of thermal sensation in a radiant cooled room by modified PMV index.
Miyanaga T, Nakano Y
Sweden, Stockholm, KTH Building Services Engineering, 1998, proceedings of Roomvent 98: 6th International Conference on Air Distribution in Rooms, held June 14-17 1998 in Stockholm, Sweden, edited by Elisabeth Mundt and Tor-Goran Malmstrom, Volume 2, pp 125-131, 8 figs, 4 tabs.
The objective of this study is to develop a method for analysing the thermal environment and the thermal sensation in the radiant cooled room.
In this paper, detailed three-dimensional models of the room and the indoor occupant were constructed and the steady-state thermal environment was analysed by the conjugate heat transfer analysis of thermal radiation and convection. The modified PMV index was proposed to evaluate the thermal sensation of the occupant in the asymmetrical thermal radiant environment such as the radiant cooled room. The modified PMV index was simply introduced by replacing the heat exchange by convection and radiation around the real human body, which approximately calculated in the Fanger's equations for the PMV index, with the analysed results around the body surface model.
The analysed values of air temperature and wall temperature distributions in the room were in good agreement with the measured values. The modified PMV index was closer to the actual thermal sensation by real subjects than PMV indices. The validity of the analysis method and models used were examined.
#NO 12065 CFD simulations of contaminant transport between two breathing persons.
Bjorn E, Nielsen P V
Sweden, Stockholm, KTH Building Services Engineering, 1998, proceedings of Roomvent 98: 6th International Conference on Air Distribution in Rooms, held June 14-17 1998 in Stockholm, Sweden, edited by Elisabeth Mundt and Tor-Goran Malmstrom, Volume 2, pp 133-140, 12 figs, 2 tabs, refs.
Experiments have shown that exhalation from one person is able to penetrate the breathing zone of another person at a distance. Computational Fluid Dynamics (CFD) is used to investigate the dependency of the personal exposure on some physical parameters, namely: Pulmonary ventilation rate, convective heat output, exhalation temperature, and cross-sectional exhalation area. Full-scale experimental results are used to calibrate/validate the CFD model. Respiration, although an inherently transient phenomenon, is simulated by steady-state CFD with reasonably good results. Different geometry's and grid distributions are tested to see what level of complexity is necessary. To further evaluate the experimental results, the CFD simulations are then used to perform parameter variations. The simulations show that the simulated personal exposure is very sensitive to variations in the convective heat output of both the exposed person and the exhaling person, and in the cross-sectional exhalation area and the pulmonary ventilation rate of the exhaling person.
#NO 12066 Combined simulation of airflow, radiation and moisture transport for heat release from human body.
Murakami S, Kato S, Zeng J
Sweden, Stockholm, KTH Building Services Engineering, 1998, proceedings of Roomvent 98: 6th International Conference on Air Distribution in Rooms, held June 14-17 1998 in Stockholm, Sweden, edited by Elisabeth Mundt and Tor-Goran Malmstrom, Volume 2, pp 141-150, 11 figs, refs.
As the thermal sensation of humans depends directly on heat transfer characteristics between the body surface and the surrounding environment, it is very important to clarify the heat transfer characteristics of a human body surface in detail. This paper describes a combined numerical (NOTE I ) simulation system of airflow, thermal radiation and moisture transport based on a human thermos-physiological model used to examine the total (sensible + latent) heat transfer characteristics of a body surface. The human body is assumed to be naked (NOTE 2). flow, temperature and moisture fields are investigated with 3-dimensional Computational Fluid Dynamics (CFD). The CFD uses a low-Reynolds-number type k- e turbulence model, with the generalised curvilinear coordinate system (Boundary Fitted Coordinates) to represent the complicated shape of a human body. Thermal radiation is calculated by means of Gebhart's absorption factor method, and the view factors are obtained by the Monte Carlo method. Gagge's two-node model is included to simulate the metabolic heat production and the thermoregulatory control processes of a human body. However, heat loss due to respiration is specified in advance and is not included in the simulation directly. The prediction results agree well with those of an actual human body in a similar situation.
#NO 12067 Integral simulation of the human thermal system.
Conceicao E Z E
Sweden, Stockholm, KTH Building Services Engineering, 1998, proceedings of Roomvent 98: 6th International Conference on Air Distribution in Rooms, held June 14-17 1998 in Stockholm, Sweden, edited by Elisabeth Mundt and Tor-Goran Malmstrom, Volume 2, pp 151-158, 8 figs, refs.
In this work a numerical model that permits to simulate the human body thermal system is presented.
This computational model is based on the integral energy balance equation for the human body tissue, arterial and venous blood and mass balance equation for the blood. In the simulation of the human body, which is divided in 105 nodes, the following phenomena are considered: heat conduction through the tissue, heat exchange by radiation between the external tissue and the surrounding surface, internal metabolism, heat loss by evaporation and respiration, blood circulatory convection and heat exchange by convection between the external tissue and the environment. It was used a thermoregulation model to control the body temperature.
The model reproduced well the experimental data and can be used to predict thermal comfort conditions and local discomfort in subjects inside an acclimated environment.
#NO 12068 A study of the air quality in the breathing zone.
Hatton A, Awbi H B
Sweden, Stockholm, KTH Building Services Engineering, 1998, proceedings of Roomvent 98: 6th International Conference on Air Distribution in Rooms, held June 14-17 1998 in Stockholm, Sweden, edited by Elisabeth Mundt and Tor-Goran Malmstrom, Volume 2, pp 159-166, 12 figs, 2 tabs, refs.
The paper deals with the differences in the air quality between that perceived by the occupants (breathing zone) and that in the occupied zone as a whole. An environmental chamber with a displacement ventilation system has been used to carry out the measurements with the presence of a heated mannequin and heat sources. Measurement of the age of air distribution in the chamber were carried out for different room loads. It has been found that the perceived air quality for a seated mannequin is about 40% better than the average value in the occupied zone. However, for a standing mannequin the difference is only about 10%.
#NO 12142 Dusty, dry air and sick building syndrome.
Burt T S
EPIC '98, Volume 1, pp 315-320, 3 tabs, refs.
This investigation was carried out on a mechanically ventilated office building with a high prevalence of occupant symptoms. The commonest complaints were of dry air, stuffy air and noise. Occupant symptoms, however, were most strongly associated with reports of dusty air and static electricity. Allergic and asthmatic people suffered the most. Cleaning standards were high, and upgrading the air filters failed to give improvements in occupant symptoms. Air flows to the rooms were adequate, but air movements in the rooms were poor. Remedial measures should focus on improving air distribution, rather than increasing air flows.
#NO 12144 Personal exposure to environmental tobacco smoke in eight European cities.
Phillips K, Howard D A, Bentley M C
EPIC '98, Volume 1, pp 345-350, 5 figs, 4 tabs, refs.
Exposures to respirable suspended particles (RSP) and both the particulate and vapour phases of environmental tobacco smoke (ETS) were monitored in eight European cities. Over 1500 housewives and office workers participated in the studies by wearing personal monitors over a 24-h period to assess exposures in the home and workplace. Based upon median 24-h time weighted average (TWA) concentrations, the most highly exposed subjects throughout Europe were office workers living and working with smokers. The median TWA RSP, ETS particle and nicotine levels for these workers across the eight cities were 58, 12 and 1.2 ugm-3 respectively, with highest RSP levels found in Barcelona and the lowest in Stockholm. Similarly for housewives living with smokers, the median RSP, ETS particle and nicotine levels were 52, 4.1 and 0.63 ug m3 respectively, with lowest RSP levels in Bremen and highest in Turin. ETS exposures were highest overall in the Mediterranean cities, Barcelona and Turin.
#NO 12151 Thermal comfort and indoor air quality in forty-three flights.
Haghighat F, Allard F, Megri A C, et al
EPIC '98, Volume 2, pp 439-444, 6 tabs, 3 refs.
This paper reports the results of thermal comfort and indoor air quality studies in forty-three flights with a duration of more than one hour. The measurements were performed continuously during the whole flight (from the departure gate to the arrival gate) and the parameters monitored were temperature, relative humidity and carbon dioxide concentration. The results were then compared with the ASHRAE Standards for the thermal and indoor air quality. The evaluation of the indoor air quality was based mainly upon comparison of the carbon dioxide concentration with standards in indoor environment: carbon dioxide, is an excellent indicator of indoor air quality.
The relative humidity level was far lower than the limit set by the ASHRAE Standard (55-92). The level of carbon dioxide concentration in most of the flight was higher than what recommended by the ASHRAE Standard (62-89).
The low level of humidity and high level of carbon dioxide concentration indicate that the crew and the passengers were dissatisfied with thermal comfort and the quality of the air in the cabin.
#NO 12185 The influence of nocturnal ventilation reduction on indoor air quality.
Gunnarsen L, Sakr W, Haghighat F, von Grunau M
UK, Garston, BRE, 1999, proceedings of Indoor Air 99, the 8th International Conference on Indoor Air Quality and Climate, and the Air Infiltration and Ventilation Centre (AIVC) 20th Annual Conference, held Edinburgh, Scotland, 8-13 August 1999, Volume 1, pp 1-6.
The energy saving practice of stopping ventilation systems at night may reduce the daytime air quality. Sorption phenomena where pollutants absorbed at night are remitted during the day and the general slower removal of pollutants at the reduced average ventilation rates will contribute to the deterioration of air quality at intermittent running systems. The purpose of the study was to investigate the impact on construction product emission during the day from reduced ventilation rates at night. Experiments were performed in three small-scale chambers of Climpaq type with dilution systems. An untrained panel of approximately 45 human subjects assessed the air quality in terms of acceptability. It was found that the intermittent ventilation reduces the daytime air quality significantly for the investigated new surface materials. If the ventilation is stopped 12 hours every night, the increase in ventilation rates required to maintain the same air quality as for continuous ventilation may be more than 100%.
#NO 12394 Modern ventilation techniques. Case studies scenario.
Booth W B
UK, Building Services Research and Information Association (BSRIA), Technical Note TN 3/99, 26 pp, 13 figs, 6 tabs, 5 refs.
Reports on an assessment of three headquarters type buildings which use mixed mode ventilation, to determine whether concerns about buildings which use passive ventilation and cooling techniques with some mechanical ventilation for peak loads will provide acceptable comfort conditions. The building indoor environment was assessed in a monitoring programme over two two-week periods (one winter, one summer). An occupant questionnaire was distributed. BRE building sickness index was determined for each building with one building being in the cause for concern category, and one in the cause for further investigation category, and one showing minimal problems.