Build a Solar Home and Let the Sunshine In

Article Tools

Image Gallery

Print

E-mail

Comments

RSS

6. Provide thermal mass (tile floors and brick or masonry walls) in the south side of the house. Mass absorbs and stores heat when sunlight strikes it or when its temperature is lower than the air temperature. As the room's air temperature drops below the mass' surface temperature, heat is released and the air is warmed. Temperatures indoors remain relatively stable and comfortable, despite dramatic oscillations in outdoor temperatures.

The mass in floors, framing, wallboard and furniture is usually sufficient to accommodate the solar heat in sun-tempered homes. But when you build a full passive solar design with 'up to 12 percent south glass, you need to add extra thermal mass in the form of tile, concrete floors, or masonry walls or planters. For optimal results, some mass should be in direct contact with the incoming sunlight throughout the day. The mass also should be distributed throughout the house. Add about 7 square feet of 4-inch-thick mass for every 1 square foot of south glass above the 7 percent minimum. One easy, inexpensive way to add this mass is to choose a concrete slab-on-grade foundation.

In addition to these solar design factors, follow these two principles that apply to all energy efficient homes:

7. Insulate and seal the structure well. Careful attention to detail is essential. Insulation should not be compressed and air should not leak in. If you can't get as much south glass as you would like, adding extra insulation can result in the same overall lower energy consumption. judkoff recommends insulating at least to the level prescribed by the International Energy Conservation Code or ASHRAE 90.2, which are region-specific recommendations for the building-envelope elements and mechanical systems. Choose energy-efficient windows and consider using insulated shades to keep heat from escaping at night (and to keep the heat out in the summer), especially in cold climates. Entryways separated from the main living space by an, inner door are especially helpful in preventing cold air from rushing in whenever the outside door is opened.

8. Correctly size the heating and cooling system. Many solar homes require almost no additional heat, so you will need a much smaller, less expensive heating system. A woodstove or natural gas wall heater may be sufficient, or you can connect baseboard radiators to your hot water heater. The insulation and thermal mass features of a solar home make it more resistant to summer overheating, and in some climates you may get by with using ceiling fans instead of air-conditioning.

RSS | Comments | E-mail | Print