AIVC - Air Infiltration and Ventilation Centre

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air change rate

Measurements of air change and energy loss with large open outer doors.

The paper describes measurements made on large doors - 10 to 20 m2 in 2 buildings in Narvik. The air change was measured with the tracer gas (SFg). The method of constant concentration or decaying concentration of the tracer gas was used. The dosing, measuring and calculation of the air change was made with a Briiel & Kjaer gas analyser type 1302 and computer. Use of the decaying method was best with short opening times. The opening of the door in 5 to 7 minutes gives an air exchange of 500 m³ to 1300 m³ or an air change from 0.2 to 1.0.

The Influence of Indoor Tobacco Smoking on Energy Demand for Ventilation.

The number of smokers differs mainly with age, sex, education, profession, and cultural background. The change in habits from the 2nd World War till today in form of increasing number of female smokers and decreasing number of male smokers is significant. The smoking of tobacco causes pollutants in the form of volatile organic compounds, particles, and carbon monoxide. Many of the pollutants are carcinogenic. In some cases the concentration of specific tobacco smoke related pollutants in room air may be higher than the maximum allowable concentration.

The effect of Various Inlet Conditions on the Flow Pattern in Ventilated Rooms - Measurements and Computations.

A test room which was built at a scale 1:5 to the original one has been used to investigate air-conditioned rooms. The original room was specified by the international project IEA ANNEX 20. A lot of experiments were made on different inlet geometries and air change rates. Velocities and turbulent quantities were measured not only in the inlet plan but also in the room itselfby means of hot wire anemometry. The ammonia absorption method according to Kruckels has been applied to determine the heat transfer coefficients at the walls. Qualitative results were obtained by laser light sheets.

Tracer gas mixing with air.