The research described in this paper is part of a project aimed at improving energy costs and the indoor environment of atrium buildings. Tracer gas techniques were used to assess the ventilation performance in terms of air distribution and contaminant migration patterns and to measure the air infiltration rate of a three-storey atrium. This atrium serves as an entrance to a large office-laboratory complex.
A Probabilistic model of air change rate in a single family house based on full-scale measurements has been developed. The probability of air change rate exceeding certain prescribed limits (risk of improper ventilation or excessive heat flow) is evaluated by utilising the distribution function based on calculated air flow rate. In this way the results are expressed in terms of the R-S model generally used in the safety analysis of structures.
The common way to determine air infiltration, exfiltration and interzonal flows from tracer gas measurements in multizoned buildings is to rely upon the standard single or multizone model, Vc(t) = Qc(t)+p(t) . Here c, p are zonal tracer concentrations and injections, t is time and V, Q are the sought volumes and flows. This model may work well provided that all zones are sufficiently well mixed and all flows really are constant during the measurements. The latter can be doubtful in naturally ventilated buildings, especially as the measurements may require several hours.
Although the power law has been broadly accepted in measurement and air infiltration standards, and in many air infiltration calculation methods, the assumption that the power law is true over the range of pressures that a building envelope experiences has not been well documented. In this paper, we examine the validity of the power law through theoretical analysis, laboratory measurements of crack flow and detailed field tests of building envelopes.
It has been estimated in the Energy Conservation in Buildings and Community Systems Strategy Plan (IEA, 1994c) that about one quarter of all energy is consumed in dwellings within the countries of the Organisation for Economic Co-operation and De
The stack effect provides the driving force for vertical air movement within buildings. Its effects are especially pronounced in high rise developments, where the air leakage associated with elevators, stairs and service shafts can be a major concern. Stairwells and lift shafts themselves provide occupant access to those floors above or below ground level as well as providing routes for the movement of air. A knowledge therefore of the air movement characteristics if such shafts is vital in understanding the ventilation and leakage patterns in medium and high rise buildings.
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