Good indoor air quality and thermal comfort and good energy-efficiency can be achieved simultaneously only if the amount of ventilation can be demand-controlled. Two approaches are discussed in the article: CO2- control and use of so-called air quality sensors. The first experiments have been promising but further development of equipment is still needed, in order to improve the reliability and economy of demand-controlled ventilation.
Describes approach based on the Predicted Mean Vote concept as a suitable index of discomfort for housing with evaporative cooling. This index accounts for all important environmental factors and in addition allows dynamic modelling of human responses to the thermal environment, such as adjusting clothing levels and metabolic rate. The computer program TEMPAL is used to predict internal environmental conditions within a dwelling. TEMPAL is shown to be sufficiently accurate for this purpose by comparing predictions with monitored conditions.
Describes automatic equipment for measuring thermal comfort based on resultant surface temperature, convective heat flux density, air temperature and relative humidity. Results obtained in an environmental chamber are presented and evaluated.
The objectives of a ventilation system are to provide an aerial environment in which 1, animals' health and productivity can be maintained, 2, the stockman's comfort and health needs are satisfied, and 3, the building and equipment are protected from damage. Criteria for evaluating ventilation include: thecontrol of air temperature and air speed at animal height, the control of relative humidity and prevention of condensation, and the maintenance of tolerable concentrations of gases, dust, and airborne microorganisms.
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