On White Roofs and Energy Savings

Roof Painting in TaurangaGlobal warming is a real thing. Nobody knows how its detractors still claim it to be a hoax, but scientific data from the last few decades are more than enough proof. As a result, the world is doing everything it can to at least alleviate (if not put to end) the effects of climate change. Alternative energy and cutting back on fossil fuels seem to occupy headlines more often.

Some folk propose a simple yet apparently scientifically based trick: painting your roof white. But before you go ask any local roofer such as Kiwispout NZ LTD for a roof makeover, you must know how things work.

Black And White In The Sun

Painting your roof white can work in theory. After all, black (or any dark colour) absorbs light and converts it into other forms of energy. Often, this energy is heat. And anything that’s dark-coloured can get pretty hot and heat up everything else around it. In the case of roofs, it’s the interior underneath. Homeowners with dark roofs compensate by turning the thermostat further down, making their energy bills balloon.

White, on the other hand, reflects light and produces less heat. Nobel Prize winner Steven Chu says that painting roofs white or with another hue helps alleviate global warming by sending sunlight back into space. He claims that doing so is equal to the world going completely car-less for 11 straight years.

The truth is not that simple, however. Civil and environmental engineering professor Mark Jacobson claims that while white roofs cool homes down, the ground heats up. This is due to reduced cloudiness, which allows more sunlight to hit the ground. This conclusion complements the results of a study by the National Centre for Atmospheric Research in Colorado, U.S.A. The NCAR says that while white roofs can help in the summer, they won’t help much during winter.

Experts say that other climate change-fighting methods are better. They propose the pumping of sulphur particles into the atmosphere so they can reflect sunlight back, or just install more solar panels on roofs. But the world lacks both resource and more refined technologies to make such a reality.

It all falls down to necessity. A lighter-coloured roof can cool down a home. But you’ll have to live with various drawbacks, just like anything else. 

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