“Roof spaces can get up to around 50 degrees in the New Zealand summer,” Paul says. “Without the right ventilation in the roof space, the temperatures in the house rise because of this ambient heat created.”
The solution to that, he says, is a product that’s been used frequently in the United States and Australia for a couple of decades, known as the Solar Star. It’s a solar-powered fan that’s installed on the roof to pull hot air out of the roof cavity and cool the house down.
“The Solar Star has a solar panel that drives a mechanical fan to remove heat in summer, and in winter, the fan removes moisture build up, reducing both heating and cooling loads throughout the year.”
While the reduction of heat in the roof space is vital in the summer months to cool the overall temperature in the house, in winter it is just as important for moisture to be removed, which often builds up in the roof space.
“That moisture can get into the insulation, which reduces its efficiency, and it can also move down into the house through the wall linings and ceiling. Dry air is easier to heat, which is why if the moisture is effectively removed, any heating system will work more efficiently.”
Because the Solar Star is completely solar powered, once installed, it is free to run, and over time, reduces the costs of heating and cooling the home.
“They’re also incredibly popular in commercial spaces like factories and warehouses where there is too much heat build-up, and work well to reduce this in these large-scale settings, as well as in domestic homes.”
The roof flashing system onto which the Solar Star fans are installed is BRANZ appraised. “These are also only installed by a nationwide network of certified, specially trained Hometech installers,” Paul says.