Solving house heat problems
Over the years we have had many discussions with people who find their home to be hot and uncomfortable, and want a cooler house. Here are is one such case that we come across and how we solved the problem:
We installed Insulation but house still gets hot
“Our whole house gets quite hot and uncomfortable, particularly in the afternoons. We installed ceiling insulation to keep us cool, but the house still heats up and stays too hot inside the rooms. The house is an old Queenslander type with a high-pitched metal corrugated roof.”
Here’s what’s happening
The roof is acting like a giant solar collector, getting hot during the day, and heating up the roof space. Even the insulation in the roof cavity resting on the ceiling is getting quite hot. There is no airflow in the roof cavity to allow the heat out. The built-up heat in the roof space, including the insulation, then radiates heat down into the rooms underneath all day, and even for many hours after the sun has gone down for the day.
Our suggested solution
The obvious solution is to fit a solar roof ventilator to continuously remove the hot air from inside the roof space, starting from early morning, as the roof starts to heat up during the day. This begins from first light in the morning. Because the solar roof ventilator extractor fan is removing the heat all day, the roof space never gets the chance to heat up at all. It will always remain measurably cooler in that space. The ceiling insulation does not get the chance to get warm, and therefore it cannot radiate heat down into the rooms underneath.
Install at least four metal eave vents.
Any hot air that is removed needs to be replaced by cooler fresh air, so if the roof space is sealed up, you need to let cool replacement air in. You can do this by installing at least four metal eave vents per solar ventilator, evenly around the perimeter of the house. This will allow cool fresh air to enter and move across the ceiling from all directions, picking up the heat, before being expelled as warm or hot air through the solar ventilator.
