Although infiltration of outside air across the envelope of a building has been considered of prime interest in relation to energy conservation and indoor air quality, it also important to understand the way in which air moves between zones within a building. A knowledge of the air movement pattern enables the transfer of pollutants or heat to be determined. In order to achieve this, a number of experimental methods have recently been developed, using either single or multiple tracer gases. (See, for instance, references 1,2,6,7,9) .
A multicell air flow computer program is used to determine the influence of 1) open windows and 2) closed internal doors on the ventilation rate of a semi-detached house. The changes in interzone air movement and room air change rates are also examined. Tracer gas field measurements used to validate the multicell program show good agreement with the predicted values. Results show that opening windows can alter significantly, not only the overall ventilation rate of the building, but also the individual air change rates in rooms.
This report describes tracer gas measurements and pressurization tests made on two low-cost houses about one year after their construction. The influence of wind speed on the ventilation rate was found to be significant, whereas stack effect was found to have no significant influence. Infiltration rates of 0.24 and 0.34 h-1 were found. These values are very low for Belgian dwellings. A pressurization and depressurization test was performed for each house at pressure differences between 5 and 150 Pa. The ageing effect was found to be quite substantial.
Discusses the installation of mechanical ventilation with heat recovery in residential buildings. The various ventilation strategies are summarized for both blocks of flats and single houses. Building components and guidelines are described.
Discusses the problems arising from inappropriate ventilation in highly-insulated flats and houses: outlines the advantages of ventilating systems with heat recovery as a possible solution. Deals with the advantages of combined ventilating and space heating installations including those which can blow air directly into bedrooms.
Discusses the various measures used to achieve the energy-conservation aims of the Federal Republic of Germany thermal insulation regulations of 1 January 1984 and to counter the health problems that arose as a result of higher fuel prices leading to reduced domestic fuel consumption in conjunction with poor ventilation. Discusses the advantages of installing heat recovery based central air conditioning systems with filters which are eligible for tax relief.
Twelve energy-efficient houses in Eugene, Oregon, USA, were measured for effective leakage area using blower door fan pressurization. Air exchange rates over a period of several hours were determined by tracer gas decay analysis.
This paper describes the procedures used in residences for rapid grab-sample and time-dependent measurements of the air-exchange rate and radon concentration: the radon source magnitude is calculated from the results of simultaneous measurements of these parameters. Grab-sample measurements in three survey groups comprising 101 US houses showed the radon source magnitude to vary approximately log-normally with a geometric mean of 0.37 and a range of 0.01 to 6.0 pCi/l/h.
An energy-efficient residence in Mt. Airy, Maryland, USA, was monitored for aldehydes and radon in order to develop relationships between air infiltration rates and contaminant levels. One fifth of the measured formaldehyde concentrations were in the range that may cause health concerns. These concentrations were measured under very low air infiltration rates. Increased ventilation was effective in reducing high concentrations. Use of the heat exchanger led to an increase in the air infiltration rate which resulted in a substantial reduction of formaldehyde levels.
To quantify the inferred elevated radon concentrations in energy efficient homes caused by lower air infiltration due to airtightness, an attempt was made to eliminate some of the more important conflicting parameters by measuring pairs of adjacent homes i.e. comparing retro-fitted or new houses with a conventional neighbouring dwelling.