What is an Air Test?
Air Tests are known by a few, various terms including Air Leakage Testing, Air Tightness Testing or Air Permeability Testing. These tests are carried out to ascertain the amount of air that is able to escape through the outer shell of a building over a given time. It then gives you the ability to highlight / eliminate the areas where air is currently escaping where it shouldn’t be.
How Does it Work?
The test works by using a large electric fan to depressurise the building to a specific level. As it does this, air from outside will be drawn in via any gaps in its outer shell. The test equipment can calculation the amount of air leakage by measuring the resistance against the fan. We can identify where air is escaping from the building by using smoke which will blow into the room in the vicinity of any leaks. At the moment the regulations require a maximum air leakage rate of 10m3 per hr/m2 @50 pascals, but targets can vary depending on the components used in the construction of the building.
Why Air Test?
When you heat a house, warm air rises. It will try to find its way out of a building as quickly as it can, therefore drawing cold air in from outside. The more air tight a building is, the less often less often the air is changing within the property meaning, less energy is required to maintain the warmth inside the building. A building needs to breathe non the less, so must have forms of ventilation. But the test is in place to make sure the ventilation is controllable. UK Building Regulations now specify that all new dwellings meet a certain level of Air Tightness as specified in the SAP Calculations.