Uses a simple computer simulation program for the assessment of the thermal performance of award-winning architect-designed houses in the Brisbane area.
States that windows and doors are the biggest source of energy loss in a house. This happens by air infiltration, conduction and radiation. Covers ways of cutting these energy losses to a minimum, including weatherstripping, installing storm doors and incorporating an air lock into the entrance door design.
Sets out the design and construction of pressure test rigs for use in studying leakage rates of windows and doorways in the Arts building of Sheffield University. Tests 7 doors (including fire doors) and selected windows, categorized according to deterioration of sealants. Finds that window leakage is far in excess of the suggested leakage from the CIBS guide (results of infiltration coefficients range from 0.911-6.097). Shows that 56% of the airflow across a doorway is due to the gap between the door bottom and the floor, and that weatherstripping the door reduces the flow by approx. 50%.
Briefly reviews definitions of airtightness, sources of leakage in buildings and describes the "blower door" method of measuring air leakage. Describes typical results obtained, names and addresses of some manufacturers of blower doors and the difficulty in relating air leakage results to air infiltration rates. Briefly discusses other methods of testing for airtightness.
Uses a two-region model to predict infiltration, to take into account non-ideal mixing of tracer gas in a building. Considers versions of this model:< 1. Fluid flows between the 2 regions and the environment in any manner provided steady state and mass balance are maintained.< 2. There is limited interchange between the regions< 3 Air flows into the first region and out of the second with (unbalanced) interchange between the two.< 4. The second region is a "dead-water" zone, which is not directly connected with the outside.<5.
Describes air leakage and tracer gas (SF6) measurements made in 42 Scottish houses. Finds that leakage in the "test" (better insulated) houses are on average 10% higher than that in the "control" houses. About 40% of the total leakage rate (at a pressure difference of 50 Pa) flows into houses through thefloor boards and the air-bricks under the crawl spaces. Tracer gas measurements indicate that average leakage rates with closed windows lie between 0.52-1.65 air changes per hour. Opening a window can increase the number of air changes by a factor of 2 to 5.
Describes the installation and use of the Gadzco blower door, as part of a house doctor's program for identifying source of air leakage before retrofitting. Discusses advantages and drawbacks of this particular type of blower door.
Reports a survey on both solar and conventional homes in north-eastern New York State. Finds that houses which are more airtight have 3 times the radon levels of conventional houses. The highest 2 levels of radon in the solar homes give doses over 30 yrs that are known to produce lung cancer in 1% of uranium miners. Summer readings in more than one half of the cases are different from winter ones by a factor of 2 or more, so that year-round measurements are necessary for precise dosimetry. The track etching technique is ideally suited for such measurements.
Compares measurements of surface pressure and response on the CAARC standard tall building model, made at 6 establishments. In general, the degree of accuracy is good and mostly within the scatter of reasonable experimental accuracy. Observes small trends in respect of pressure measurements which could be attributed to differences in the approaching longitudinal velocity spectrum and to the requirement for blockage corrections. Finds no obvious trends in the dynamic response measurements, where the majority of the data compares within +-15%.
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