Airtightness Assessment of Residential buildings
blower door test, fan door, air permeability, air pressure testing, thermal imaging, thermography, condition monitoring
Airtightness - Benefits of improving the building:
- Identify contributors of heating, cooling and comfort issues which can be remedied to improve occupant comfort, typically decreasing unwanted draughts and hence allergens, dust and dirt.
- Increase the value and attractiveness of the property/development to future investors.
- Obtain verification of the actual building envelope performance. i.e. quantify how “leaky” your building is for comparison to benchmarks.
- Better building airtightness leads to a reduction in loss of conditioned air and hence lower energy bills, better rejection of outdoor noise, and helps make the building "feel" better to be in.
- An added benefit of having an airtight building is a reduction in your carbon footprint as you lose less energy through the building envelope. i.e. reduced environmental impact.
- Prior/during design to advise or offer direction in your approach to achieving an airtight building.
- Conduct an on-site briefing on how to build airtight with Builder and Site Manager who in turn can brief the trades people used.
- Inspection to check air sealing is being performed through the construction stages.
Airtightness/ Blower Door Test
- Gaps are often obscured by internal building finishes or external cladding. The only satisfactory way to verify that the building fabric is reasonably airtight is to measure the leakiness of the building fabric as a whole.
- We do this by performing a blower door/air pressure test of the building. The fan creates a pressure differential to outside and measures air leakage over a range of pressures to return an air leakage result, measure in ACH (air changes/hour).
- If the test result does not meet target, we can locate where air leakage is occurring.
- With the blower door running we use diagnostic tools such as an infrared camera and tracer smoke to locate leakage areas. The images and recorded data is compiled in an audit report which provides the customer/builder with specific areas for sealing/remediation.
Thermal image (left) shows air leakage at a window surround. The air leakage is the darker coloured streaks which indicate gaps whereby external air is entering the room (blower door depressurisation test in progress to exacerbate leakage areas).