Q-We plan to paint the outside of our house this spring. What are the best colors to keep our house cooler in summer?
A-White paint does the best job of reflecting the sun’s heat. Light-colored walls will keep a home the most comfortable and keep air-conditioning usage to a minimum in the summer. In general, the lighter the color of paint you use, the more energy-efficient it will be.
Researchers say that white paint on plywood does the best job of reflecting the sun’s heat (only absorbing about 15 percent of the heat), followed by white on wood siding, white stucco, flesh-colored stucco, cream color and white/gray aluminum siding. Each will absorb less than 50 percent of the solar heat striking its surface.
These colors are followed, in order of increased solar absorption, by light gray, medium gray/blue and tan/brown (which absorbs about 80 percent of the solar heat).
If your home is brick, you would get best results by using a light-colored surface; burnt-red bricks have the highest solar absorption.
If you decide to use a darker color, however, be sure that trees or porches shade the outside walls.
Q-The air in our house feels dry. How much does it cost to operate humidifiers?
A-A humidifier can be used to add controlled amounts of moisture into the air in your home to bring the humidity to a comfortable level.
According to the experts at the Air-Conditioning & Refrigeration Institute, humidifiers don’t cost much to operate. The average home needs about a 15-gallon central unit, which actually uses less energy than does a 25-watt light bulb. Because the heat needed to vaporize the water into the living space of your home also contributes to heating the space, you can say that these systems are virtually 100 percent energy efficient.
The most effective type of humidifier is installed permanently as a central system. Just as you need to size an air conditioner properly for your home, you also should properly size a humidifier. The capacity of these systems is expressed in gallons or pounds per day and is based on the size of the space to be humidified. You or your contractor should be able to calculate the size you need.
A room with the proper humidity level ought to feel as comfortable at a lower temperature, allowing you to reduce the thermostat setting and save even more money.
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Ken Sheinkopf, with the Solar Energy Research and Education Foundation in Washington, will answer questions about energy conservation and home comfort. Write to him in care of The Orlando Sentinel, P.O. Box 211, Orlando, Fla. 32802-0211.
