Thermal sensation of tropically acclimatized subjects performing sedentary tasks under personalized ventilation (PV) was explored in this study. The study was conducted in an Indoor Air Quality (IAQ) chamber, which is capable of simulating typical office conditions in Singapore. An experimental design involving interventions in indoor ambient temperature, PV supply temperature and PV supply airflow rate, introduced blind to subjects, was conducted.
This paper introduces a manual of thermal comfort in heated rooms. The manual is a design tool to help choose structural measures and make decisions regarding building energy systems for residential and office buildings and comparable room categories. Details are given concerning the calculation algorithm and the related boundary conditions. The major part of the manual contains diagrams illustrating thermal comfort for the most various structures and installation. Some selected diagrams and figures are presented in the paper.
The segmental equivalent temperature determined by means of a thermal manikin is often correlated with the local thermal sensation of people and is used for indoor environment assessment. It is also used to assess performance of heated/cooled/ventilated car seats, etc. However, the body of the thermal manikins used at present is not as flexible as the human body and is divided into body segments with a surface area that differs from that of the human body in contact with a surface. The area of the segment in contact with a surface will depend on the shape and flexibility of the surface.
We report on a series of measurements of the temperature at Houghton Hall, Luton,over the Spring and Summer of 2003. The data show that the building tracks the externaltemperature, but that the amplitude of diurnal temperature fluctuations typically lies within 2-6 C,while the external fluctuations may be as large as 15-25 C. This buffering of the internaltemperature is largely due to the thermal mass of the space which introduces a time-lag ofbetween 0.5-3.0 hours in the response time of the interior to the exterior space, over the periodof our survey.
Underfloor air distribution (UFAD) strategy is gaining popularity during the last years, howeverresearches about the performance of such systems still need to be deepened.One of the appreciated features of this technology is the use of an underfloor plenum below a raised floor. This plenum is used to distribute the conditioned air in the rooms and makes possible to avoid large air ducts to be installed.
This paper deals with how to visibly render the thermal climate in the design and presentationtools used by different participants in the building process. The focus is on those ventilation/coolingsystems where cool air is supplied directly into the occupied zone and therefore have a potential ofgenerating a volume close to the device with poor comfort. This volume could be described as a spreading bubble. In the paper a practical procedure for rendering the spreading bubble is presented. This is achieved in a number of steps.
This paper discusses the concept and performance of a naturally ventilated building with a double-skin facade in Tokyo. The building incorporates a hybrid ventilation system (natural ventilation integrated with air-conditioning systems) that makes use of buoyancy forces generated in a vertical airshaft in the center of the building. Field measurements were made in order to evaluate the performance of the double-skin facade during the summer and winter and also the performance of the hybrid ventilation system during the spring and autumn.
We investigate two different natural ventilation regimes of an auditorium or other occupied open-plan space which is equipped with pre-cooling. The room has a low-level vent and a high level vent. The occupants act as a source of heat, which if without pre-cooling, can lead to the room becoming too warm for comfort. In the first ventilation regime, a chiller is fitted to the low-level vent, and the occupants provide positive buoyancy which drives the ventilation upwards and draws fresh air through the pre-cooling system.
Rising energy prices have contributed to the development of heat pump-based heating systems in Sweden. Low flow temperature in the secondary heat distribution system to rooms is a requirement for energy-efficient systems. This increases the thermal efficiency of the heat pump and decreases thermal losses in the distribution system. Flow temperatures in water-based systems for heat distribution in buildings have been decreased from 55C to temperatures around 30C. This is to maximize the efficiency of heating systems that are based on heat pump technology.
Equivalent temperature is a thermal index used today for assessment of the thermal comfortin vehicles. Prediction of the percentage of people dissatisfied by the thermal environment iscalculated by implementing equivalent temperature in the PMV/PPD thermal index. In this work,PMV/PPD and PD (draft rate) indices are compared for vehicle conditions, with respect to air velocity and turbulence intensity. Results indicate that turbulence intensity must be taken in consideration for higher air velocities and that PD is the predominant thermal index after a certain air velocity is reached.
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