Now that we are in the throes of the dog days of summer, most of us in the Valley of the (Broiling Hot) Sun are thinking about ways to keep ourselves, and our homes, as cool as possible.
For example, you might have heard that painting your home white can help keep the interior and its residents cooler, so maybe you'rewondering if it’s time to repaint your abode.
But is this true, or is it just lore?
Toget the scoop, we consulted with experts in metro Phoenix who were able to shed some light on this heatedtopic.
More:Does opening the garage door just a crack help keep your house cooler?
Does painting your house white keep it cooler inside?
John Antioco, owner of CertaPro Paintersinnorth Scottsdale, saidpainting your house a lightcolor could definitely help to keep it cooler inside.
“Dark-colored homes absorb 70 to 90 percent of the radiant energy from the sun, which is then absorbed into the home. White —or other light, neutral colors —will reflect most of the heat away from your home,” he said.
What is the science behind this phenomenon?
Keeping your house cool relates to the ability of the paint to reflect heat as well as light, said Aashay Arora, Ph.D., chief technology officer and co-founder at EnKoat, a Phoenixcompany that makes an energy-efficient coating for building exteriors.
“The component of the light spectrum that causes surfaces to become hot is called infrared radiation. The ability of any paint to reflect infrared radiation depends on the composition of the paintand not just its color,” Arorasaid.
“Some paints contain pigments or additives which enable them to reflect this infrared radiation. These paints are therefore called cool-roof paints. Coincidentally, most of these cool-roof paints are also lighter in color.
"However, there are paints which have darker colors but reflect more heat than lighter colors, and as a result are cooler. Such a characteristic of the paint can be quantified using its thermal emissivity testing, which is a measure of how much heat a particular paint can reflect/absorb.”
Does a white house use less air conditioning?
“Yes, definitely,” said Matt Kowalski, founder and owner of Kowalski Paintingin Gilbert. “By painting your house white, you can reduce the overall temperature in your house, which in turn reduces your air conditioning use.”
Antioco pointed out that other factors affect your air-conditioning use, including the condition of the home’s stucco, wood, brick, insulation, substrate, window seals andshades.
“If there are cracks in the stucco, it’s important to have those repaired in addition to getting the house painted,” Antioco said.
He noted that using light paint colors inside the home also can make a difference.
“When you use dark colors in a room that gets a lot of natural sunlight, the sun will absorb into the room more, making it hotter and requiring your air conditioning to work harder,” he said.
Do other light paint colors keep your home cooler?
“The short answer is yes,” Antioco said, adding that any light neutral color will make a difference in light absorption, and therefore heat.
“All paint colors have an LRV, or light reflective value, ranging from 0 (black) to 100 (white). The lower the LRV, the darker the color. A higher LRV indicates a lighter color that reflects more sunlight and therefore absorbs less heat,” Antioco said.
How to choose the best paint color for your house
You've got a few factors to consider.
“In general, darker colors just don't hold up well in Arizona due to the extreme sun we get,” Kowalski said. “However, that doesn't mean you can't use high-quality products to extend the life of a paint job.
"When choosing a color, it’s important to think about durability and what will last the longest, but it’s equally as important to pick colors that you like. I always recommend going into a paint store and getting a few samples to test before making any big decisions.”
Checking with your homeowners association or city guidelines when choosing an exterior paint color is also important, Antioco said. And he has one more bit of guidance for homeowners:
“If your house hasn’t been painted in several years, when you repaint, even if it’s the ‘same’ color, it is going to look different than it does now,” Antioco said.
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