The ventilation heat loss has been assesed for twelve factory/warehouse buildings covering a range of construction types. This has been achieved by the design and development of a new mobile test facility which can pressurise buildings up to and beyond 20,000 m3, depending on their air leakage characteristics. The results of the measured air leakage characteristics have been translated into predicted air change rates for mean wind speeds and average internal/external temperature differences, from which the average ventilation heat loss has been calculated.
The heat loss associated with the external fabric of a building has been greatly reduced by the increased levels of modem insulation, but heating losses associated with cold external air flowing into a building via leakage points in the external facade are still a major problem. Some ventilation is necessary but a detailed knowledge of this leakage would enable the major heat loss routes to be blocked. A crack has been studied which has hot air of a known temperature and flowrate passing over it.
This handbook gives a comprehensive explanation of the theoretical and practical aspects of measuring important parameters for understanding air infiltration and ventilation within buildings. Discussed parameters include: airtightness of the building envelope and its component leakage paths; air exchange rates within a building and with the external environment; efficiency of the ventilation system; flow rates in the ventilation network. It has been designed so that material suited to differing levels of expertise is readily accessible.
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