English

Completed studies indicate that emissions from indoor sources, including those from unvented gas appliances, do not cause any undesirable effects in buildings with normal ventilation rates. However, recent energy conservation measures aimed at reducing ventilation rates have increased the problem of indoor pollutant levels, and there is a need for new, more detailed data on the indoor environment. Describes a programme initiated by GRI to collect such data and to develop control techniques for indoor pollutants.

Describes a system installed in the EKONO office building in Helsinki which allows the amount of CO2 in the exhaust air to control the ventilation rate. Uses a CO2 indicator, and adjusts the mixture of exterior and recirculated air so that the amount of CO2 during working hours is kept on ca 700 ppm. Describes use of equipment during winter 1981-82, when exterior air flow is registered. Measures the proportion of CO2 locally in order to study occasional variations that may occur. Studies the proportion of other pollutants in the room air with a gas chromatograph.

Makes an experimental investigation of the distribution of pressure differences across the walls of a 20-storey student residence building at the University of Ottawa. Measures the wind velocity at the test building as well as the temperature distributions both inside and outside the building.

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.