infiltration

Evacuation of people from their homes and workplaces is a standard response to the hazards created by the release of toxic gas. However, by staying indoors a person can take advantage of the clean air stored within the house volume, as well as the damping the house provides for sudden changes in outdoor toxic gas concentration. The relation between indoor and outdoor concentration is explored in this study, where it is shown that in most cases the risk of exposure to high concentration levels is substantially reduced by remaining indoors during the entire period of toxic gas release.

Discusses energy saving measures taken in the Ekono office building, headquarter of Ekono consulting engineers, situated near Helsinki. Describes the use of hollow slabs for intermediate floors, tight window construction, the extract air window system, efficient lighting and computer control of ventilation. It is planned to control ventilation by monitoring the concentration of carbon dioxide in the building. Reports measurements of infiltration rate with nitrous oxide as a tracer gas using both constant concentration and decay rate techniques.

Discusses standards and guidelines used for calculating the heat demand over a heating season. Notes inadequacy of current methods, in particular the inadequate account taken of certain environmental conditions and of particular window constructions. Proposes improved sizing procedure to take into account heat loss due to infiltrating air. Discusses simplifying assumptions. Gives expressions for critical heat output and for the quantity of air infiltrating a room.

Presents a technique using fan pressurization results and weather data to calculate infiltration. The geometry, leakage distribution, and terrain and shielding classes are combined into two reduced parameters which allow direct comparison of wind-induced and temperature-induced infiltration. Using these two parameters and the total leakage area of the structure (found from fan pressurization) the infiltration can be calculated for any weather condition. Presents experimental results from 15 different sites for comparison with theoretical predictions.

There is a need for correlating results of pressurization tests with infiltration tests, making it possible to predict the infiltration rate of a building on the basis of a pressurization test. Discusses problems with calculation models

A bibliography of references on the subject of air infiltration, lists references in alphabetical order of author and gives short index to broad subject headings.