A rational method is presented to determine the locations within a building where the highest average concentrations of contaminants may occur. Using this procedure, the number of sampling points necessary for indoor air quality (IAQ) evaluation of a building is reduced to a minimum. Thus the time and cost necessary for building evaluation and analysis can be decreased. Experimental measurements made in a research house are presented to validate the method.
A comprehensive theoretical framework is presented, based on the use of moments of concentration histories ie multiplying concentration readings by time of reading and then integrating with regard to time. The concept can be used to characterize either the diffusion of the supplied air or a contaminant released within the room. Results are presentd from about 50 measurements demonstrating the usefulness and practical applicability of the approach for assessing air quality in ventilated buildings. Different experimental procedures have been explored and are discussed.
Indoor air quality is determined by the sources of the contaminants and the methods used to control their concentrations. To predict the quality of air, algorithms are needed to model the rates of generation, transfer and removal of contamina
States that although the conditions for a comfortable climate are well known - especially temperature and air humidity - increased concern with energy conservation means it is important to discover what effect energy conserving measures have on the health,well-being and efficiency of people. Pressing questions are - how far can room temperature be lowered without affecting comfort and how is room air quality affected by a lower air change rate or a reduced fresh air supply. Summarises recommended room temperatures for various levels of activity.
Describes a mathematical model for the calculation of the expected values of radon and radon daughter concentrations in indoor air. Presupposes that it is possible to obtain or measure the parameters necessary for the calculation eg the radon emanation of the building material, the radon content of the soil air, and the leakage of air from the soil into the building. Research in these areas is in progress both in Sweden and abroad.
Despite having balanced mechanical ventilation, a large number of modern buildings in Sweden have unsatisfactory indoor climate. Problems include mould, irritation of the eyes, nose and throat, skin rashes, feelings of dryness, hoarseness andheadaches. To control ventilation according to requirements the right indicator variable must be selected and the system must permit the proper control in the occupied zones. Measurements of air pollutants were carried out outside and inside a mechanically ventilated office building.
Discusses the problems associated with poor air quality in tight buildings. Considers how problem conditions can be identified and evaluated, and gives some possible solutions to improving air quality. These include turning the thermostat down slightly, increasing ventilation levels, and ensuring that themechanical ventilation system is working properly, or calling in a specialist to identify the problem.
States that in localities which must be ventilated by law such as cinemas, restaurants and assembly rooms of various kinds the fresh air supply is often greatly in excess of what is strictly needed. This excess air has to be transported, and possibly heated, cooled, humidified and dehumidified. Describes how controlling the air quality makes it possible to restrict the quantity of fresh air to the basic requirements, thereby keeping ventilation heat losses to a minimum. The control variable is the room air quality as monitored by a sensor.
States that in a tight house with a vapour barrier, an air management system is needed to provide fresh air and remove the build-up of moisture generated by the occupants. Briefly describes a typical air management system,incorporating an air-to-air heat exchanger, and discusses the need to provide an acceptable ventilation rate, which controls pollutant level but minimizes heat losses.
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