Stay Cool with Paint, Part II

In Stay Cool with Paint, Part I, we explained the connection between colour and temperature: pale colours reflect more light than dark ones. There's another aspect of reflection that also affects temperature, and that's the fact that some materials reflect more than others.

We see this in daily life, of course, because we can see our reflection in highly polished silver but not in paper. We also know that metal left in the sun will get very hot, while rubber left in the sun won't get as hot. Some things reflect better and some things absorb better.

Titanium dioxide, a mineral used in high quality white paints, reflects better than a diamond. It's also used in sunscreens, so we shouldn't be surprised that this is one of the paint ingredients that protects our homes from the heat of the sun.

Calcium carbonate and other chalk-like minerals are sometimes used as a substitute for titanium dioxide to keep paint costs down. These paints will reflect more sunlight than dark paints if they are light coloured, but they still won't reflect as much heat away from your home as titanium dioxide will. Talk with your professional painters about the kind of paint they choose, and make sure that they're using paint that will reduce your energy costs and keep you cooler and more comfortable in the summer.