Recent research from CSR highlights how better ventilation practices and control of air leakage will achieve far superior results in residential energy efficiency.
CSR House is located in Schofield in outer Sydney and its 8 star quality design continually yields important research results for architects, builders and homeowners nationally. An 8 Star NatHERS rated home like CSR House has a theoretical heating and cooling load roughly 50 per cent lower than a comparative 6 Star home (i.e. of the same location, orientation, size and layout).
CSRnrsquo;s research shows that by improving the air tightness of the 8 Star home, the actual energy required for heating and cooling can be as much as 72 per cent lower than a standard 6 star house.
The NatHERS rating system uses air leakage factors for various elements of an entire house: for the CSR House it was predicted the air inside the house will be replaced or infiltrated with outside air every two hours. This means the heating or cooling systems will need to re-heat or re-cool the air within the house every 2 hours. Initial air leakage tests confirmed this result.
Thermal images showing air leakage from (l to r): architraves; between studs; and powerpoints
Using thermography to identify the major leaks within the CSR House, the air conditioning ductwork, grilles and return air register were sealed after the initial test. After this additional sealing work was conducted the infiltration rate was improved, so the re-heat / re-cool rate was improved to 2.5 hours.
Also producing moderate air leaks at CSR House were the bathroom exhaust fan dampers; after further sealing the air exchange rate was over 2 hours and 45 minutes.
Once all the large and moderate sources of air leaks were addressed, small air leakage paths were nonetheless still occurring through the building envelope, such as at window/door architraves and reveals.
When all these items were retrospectively sealed, the infiltration air would then take three hours to fully replace the indoor air, boosting the energy efficiency measures by a further 50 per cent.
