Using the Sun
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The passion for solar energy for homes is not what it used to be; enthusiasm peaked sometime in the late 1970s. Today, even energy-conscious builders focus on improving insulation and air tightness more than on how the remodeled house will interact with the sun. But the heating, lighting, and cooling benefits of solar energy are far from lost, even if they have been forgotten by some.
Remodeling is the perfect time to improve daylighting, solar heating, and shading for your home. Solar water heating and photovoltaics can also be included in many remodels.
Many of the latest advances in solar technology have been in off-the-grid applications for homes far away from power lines. But several innovative passive-solarstrategies are suitable for the average residence. The biggest developments have been in improved windows, which make it easier to capture solar heat and daylight. But many basic solar improvements can be part of your remodeling project, especially if the remodel involves moving windows, revamping floors, building an addition, changing landscaping, replacing the domestic hot water system, or reroofing.
Using Windows Wisely
Windows are the piece of "energy equipment" most likely to be replaced or added in a remodel, whether you're redoing a kitchen or bathroom; finishing an attic, basement, or garage; or adding a whole new wing to the house. Sunspaces are a popular addition, and they are almost nothing but windows.
Windows that face the sun heat the house with solar radiation, also called direct gain. Older windows, though they let in solar heat, also lose a lot of heat in winter through air leaks and poor insulation. Today you can choose windows based on their ability to do a variety of tasks—absorb winter sun, trap winter heat inside, block summer sun, let light into the house, reduce glare or drape-fading ultraviolet light, seal tightly when closed, and open wide for good ventilation. Chapter 12 (Windows) explains how to find the most appropriate window for each of these tasks. Using the right windows, and placing them where they take best advantage of the sun, is central to a passive-solar remodel. More on Using Windows Wisely...
Incorporating Thermal Mass
For passive-solar heating, thermal mass works in conjunction with lots of south windows to capture and store the sun's heat. Materials with high thermal mass, like masonry or stone, soak up most of the heat that hits them, and gradually release heat, moderating the temperature of the house. In the winter, thermal mass stores the solar heat collected through the windows during the day, and radiates it back to the living space at night.
A rule of thumb offered by the National Renewable Energy Laboratory is that the thermal mass should have nine times as much surface area exposed to sunlight as the area of the window glass, and that the materials should be 6 inches thick. The exact materials and amounts vary, depending on where the house is.
Solar Hot Water
Many people replace water-heating equipment or put in a new pool or spa when they remodel. If you have access to knowledgeable, reliable contractors, changing over to solar water heating can save you energy and money. Solar heating for pools and spas is cost-effective almost everywhere, and solar-heated tap water makes economic sense where the climate is relatively sunny and gas and electricity are expensive.
Choose a contractor with experience and several references. Far too many shoddy solar hot-water systems were built by fly-by-night contractors in the '70s—and then were left to fall apart. More on Solar Hot Water...
Excerpted with permission from No-Regrets Remodeling by Home Energy (1997)