Roof spaces can heat up to over 50°C on hot sunny days. While increasing ceiling insulation does thermally decouple the roof space from the living spaces, any services within the roof space such as ducted air-conditioning (a/c) can be severely affected by excess heat.
The overall ability of the a/c system to cool the living spaces can be compromised if the insulation of the duct is inadequate and if the joins in the duct are poorly sealed.
Minimum R1.5 duct insulation and sealing of joins in the duct can increase the efficiency of the a/c system by up to 30 per cent. Roof space ventilators will also help to make the a/c ducting more efficient.
Get up in your roof once a year (but not when its >50°C!) to check on your duct joins and ensure there are no splits in the insulation. If your ducting is old and leaking, get it replaced – it will pay itself back in no time.
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