Major ventilation developments covering systems, measurements and design methods have taken place over the last 25 years. Our understanding about the impact of ventilation on the indoor environment and energy use has also evolved. This paper outlines these developments. Many future challenges are considered including minimum ventilation rates, energy efficient cooling, cost effective heat recovery and the development of calculation techniques.
This study deals with the ventilation performance of two storey dwellings employing stack effect ventilation to satisfy the overall ventilation requirement. The SRF (Supply Rate Fulfillment) index was used as a ventilation performance index. The experiments were implemented to measure effective fresh air rate by using tracer gas in a test house. Following are the results of the experiments and the theoretical calculations. The measured air change rate and the SRF value were fairly close to the theoretical calculation.
That study was performed in a call center. During nine consecutive weeks, temperature and outdoor air supply rate were combined and introduced to the occupants in a blind intervention approach.Those 2 variables had significant interaction effects on the workers' talk time.
Fresh air has a very important role in indoor air quality.This study aims at quantifying the costs and the gains of an increase of the ventilation rate, in an office building. Results show that a big increase of the ventilation rate leads to an increase of the installation costs, but to no change of the energy costs. The additional costs may be paid back quickly due to the productivity improvement.
This study estimated the health, energy and economic benefits of an economizer ventilationcontrol system that increases outside air supply during mild weather to save energy. A modelof the influence of ventilation rate on airborne transmission of respiratory illnesses was usedto extend the limited data relating ventilation rate with illness and sick leave. An energysimulation model calculated ventilation rates and energy use versus time for an office buildingin Washington, D.C., with fixed minimum outdoor air supply rates, with and without aneconomizer.
This paper is an overview of literature that investigates the effects of general environmentalquality, indoor air pollution, ventilation rates, thermal comfort, temperature control andnumber of persons per workspace on productivity and sickness absenteeism in offices. Thereview includes both self-reported effects and objective measurements of productivity andabsenteeism and both laboratory studies and field investigations. It turns out that a goodgeneral environmental quality increases productivity by 10-15% and decreases sicknessabsenteeism by 2.5 percentpoint.
This paper presents findings from a recent call centre study conducted in an air-conditionedoffice in the Tropics. The effects of temperature and outdoor air supply rate, each kept at twoset points within currently acceptable limits, were explored in a 2 2 balanced experimentaldesign over a 9-week period. The results indicate that both a slightly cooler thermalenvironment and improved indoor air quality improve performance by reducing average callduration. Temperature and outdoor air supply rate were synergistically related to one anotherin affecting operator performance (P < 0.062).
A 2 × 2 replicated field intervention experiment was conducted in a call-centre providing a national public telephone directory service: outdoor air supply rate was adjusted to be 8 or 80% of the total airflow of 430 l/s (3.5 h-1); and the supply air filt
Correlation analysis of subjective responses of tropically acclimatized office workers in a fieldstudy conducted over nine continuous weeks using a 2 2 balanced design with temperatureand fresh air ventilation rates as control variables revealed that several related SBS symptomsare highly correlated. Thermal comfort and acceptability of air quality exhibit a strongcorrelation, whereas perceived indoor environmental variables have poor correlations amongthemselves. Principal component analysis further improved measures to variability bycombining coherent variables into six factors.
In order to determine the a etiological factor of Sick House Syndrome (SHS), indoor airquality of 35 houses in Miyagi prefecture of Japan, where occupants are suspected ofsuffering from SHS, had been investigated during the summers in 2000-2002. Theinvestigation included the measurement of indoor chemical substance concentration and aquestionnaire regarding residential environment and subjective symptoms.As a result, the formaldehyde concentrations in 71% of all houses exceeded the guideline ofJapan.
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