Comparison of ventilation systems in an experimental building in Helsinki. Ilmanvaihtojarjestelmavertailu koerakennuskohteessa kasarminkatu 24

Performs an investigation concerning the operation of ventilation systems in an old building (a museum) after extensive repairs have been made. The new ventilation system is a supply and exhaust type. Measures ventilation rate and energy consumption for 1. mechanical air supply and and exhaust 2. Mechanical exhaust only 3. Exhaust from the secondary space only with other ventilation ducts closed. Uses nitrous oxide as tracer gas. Measurement of radon concentration shows that concentration is lower in 1 than 2, in spite of the fact that the air change rate is the same in both (0.7 ach). Difference in radon contents between 2 and 3 is small however despite the fact that 3 has a quarter of the ventilation rate of 2. Energy consumption is largest in 1 and lowest in 3.