Capturing Solar Energy for Home Heat
ONE OF THE KEY POINTS I drive home to students in my passive solar design classes at the Evergreen Institute is to design new homes and businesses around the Sun. Put another way, the passive capture of the solar energy for home heat should be the central organizing principle when designing a new home.
Architects are taught to design homes around use patterns – accommodating patterns of habitation and use preference and ensuring the smooth flow of traffic in a home. In rural areas, home design often revolves around a client’s desire to capture views for which they’ve paid dearly.
Unfortunately, very little, if any, thought is given to designing homes to capture the low-angled winter Sun, which can provide free heat for life in many areas. Doing so can dramatically reduce home heating costs and the carbon footprint of homes while increasing comfort levels immensely.
To create truly efficient homes that tap into the Sun’s generous supply of energy for heating, all homes should be designed around the sun. Begin by orienting the house to the south, so the long axis runs east to west. Then concentrate the windows on the south side. Doing so permits the low-angled winter Sun into your home, providing free heat. Once the home is properly oriented, arrange rooms accordingly to solar heat demand.
Ideally, a house should be designed so that each room becomes an independent solar collector. This requires a rectangular design – basically a one-room-deep home.
To avoid the solar trailer syndrome (long skinny homes), most passive solar home designs are two-room-deep rectangles. In such instances, it is best to place rooms that require more heat on the south side of the home. Living rooms, dining rooms, and home offices are good candidates for direct solar gain. Rooms that require less heat or are used less frequently, such as pantries, bedrooms, utility rooms, and bathrooms should be placed along the north side. The same goes for rooms like kitchens that generate their own heat.
These and a few other measures, like providing adequate overhang to shade a home in the summer, airtight design and construction, and high levels of insulation, will result in a home that heats itself naturally.
The cool thing about passive solar is that they generally cost about the same to design and build as conventional homes. A little foresight and intelligent design can reap huge financial benefits. The question is not “Why should I build a passive solar home?” but rather “Why wouldn’t you? Why wouldn’t you build a home that heats and cools itself naturally and that’s going to cost the same as a home that’s going to relegate you to exorbitant heating and cooling costs?”