The share of ventilation in the energy demand in Finnish building stock is about 50 per cent. An essential part of the ventilation heat losses is uncontrolled due to air infiltration, which only partly serves the demand of ventilation. The aim of improving the airtightness of windows and other leakpoints is to prevent the infiltration. But then, if the supply air intake is not mechanical, certain risks of insufficient ventilation occur. In thereport, the interconnection between the building envelope and ventilation system is studied.
Uses a model to estimate the incremental risk of lung cancer associated with increased radon concentrations in indoor air resulting from decreased air infiltration caused by increased air tightness of dwellings. Gives results for selected changes in the air exchange rate. Discusses findings.
SINTEF, The Foundation for Scienti f ic and Industrial Research at the Norwegian Institute of Technology, has monitored a number of experimental low-energy houses, and also undertaken measurements in some other houses to establish the energy consumption, air tightness, ventilation rates etc. Some of the experimental houses are extremely air tight. In connection with these measurements we have made some observations on the occupants behavior related to ventilation, and their satisfaction with the ventilation system.
After years of intensive studies on indoor air pollution sources, pollution levels, condensation effects, building airtightness, and air change rates, we are now at the point to discover that no solution whatsoever to the ventilation problem is possible if compatibility with user comfort and user habits are not properly taken into account. User compatibility of aventilation strategy under todays conditions in dwellings must in fact be understood as a requirement equivalent to the purely functional ones of pollutant removal and of economy.
An important function of the Air Infiltration Centre, Bracknell, Berkshire, Great Britain, is to keep research organizations informed of on-going research into air infiltration if buildings. To fulfil this need, the Centre regularly undertakes aworldwide survey of current research. In this report, theresults of the Centre's most recent survey, completed in 1983, are used to provide a background to present European airtightness and air infiltration measurement practices. A wide range of research activities are summarized involving the use of both pressurization and tracer gas techniques.
Seven federal buildings ranging in size from 1900 to 48000 m2 of floor area were pressure tested to determine the airtightness of the building envelopes. These tests are part of a larger project to evaluate the thermal integrity of the envelopes of federal buildings. The buildings were pressurized using the air-handling equipment in the buildings and a constant-injection, tracer gas technique to measure the airflow through the fans. In addition, selected windows in some of these buildings were pressure tested separately to determine the airtightness of individual components.
The airtightness of 82 passive solar homes located throughout the United States was studied using tracer gas measurements of air infiltration and pressurization testing. The air infiltration measurements employed the tracer gas decay technique in a low-cost mode employing air sample bags and off-site infiltration determination. The infiltration rates measured under natural conditions ranged from about 0.05 to almost 2 air changes per hour (ACH). The pressurization test results ranged from 1 to more than 30 ACH at 50 Pa, with an average of about 10 ACH.
Discusses the various causes of unwanted air infiltration in dwellings. Illustrates diagrammatically the commonest structural faults leading to adventitious air infiltration and gives methods of overcoming them. Notes the average cost of such improvements.
Sick building syndrome has up until recently been diagnosed from complaints by the users of the building. Specific causes of complaints symptoms usually have not been identified. Inspection methods have been limited. Frequency of sick buil
Approximately 40% of the energy consumption in Sweden is utilized in the heating of buildings. In order to reduce the amount of energy utilized for heating purposes, more stringent thermal insulation requirements for buildings were introduced.
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