Airtightness of office and educational buildings in Sweden – Measurements and analyses

The airtightness of office and educational buildings influences energy use and thermal comfort. A leaky building is likely to have a high use of energy and thermal discomfort. The knowledge of real airtightness levels of entire buildings and their impact on the energy use is very low, except for a study carried out in the USA. Therefore two different methods of airtightness testing were applied to six entire Swedish office and educational buildings built since 2000. The first method involves using the ventilation system of the building and the second one to use a number of blower doors. Information on 30 other airtight tests was collected. During the airtightness testing the air leakage paths were detected using infrared scanning and smoke sticks.
The two methods are useful for testing entire office buildings, apartment buildings, industrial buildings and other premises.
The thirty-six tested buildings show a very good airtightness level, close to the Swedish passivehouse requirements. All previously tested office buildings in the USA, Canada and the UK are much leakier. The tested buildings showed some leakage paths, which could easily have been taken care of during construction, but are rather difficult to stop now.
The paper describes and evaluates the airtightness tests of thirty-six Swedish office and educational buildings and their implication for energy use.