Passive Solar Home Design Helps to Save Money
Photo by Jeremy Levine Design
Also called climatic design, passive solar designs makes use of heat’s natural tendency to diffuse throughout a space.
Have you ever had the experience of walking into a back bedroom or other room in your home that has had its door closed all day? It’s colder than the rest of the house, especially if you heat your house with a localized source such as a fireplace. If you leave the door to that cold room open, it will eventually come up to the same temperature as the rest of the home. This is because heat naturally migrates to cold areas, continuing its dissemination until the temperature is even.
Heat travels and affects the temperature of air and matter by conduction, convection, and radiation:
- Conduction is how heat travels through solid matter – think of a silver spoon in hot coffee. The spoon handle becomes hot even though it’s not directly touching the hot coffee.
- Convection is the manner by which heat travels through air. You have probably heard it said that hot air rises; this is convection.
- Radiation is simply heat leaving an object and warming another one, or warming the air around that object.
With these three principles in mind, solar home design can begin. It’s easiest to incorporate passive solar design into a new home, but adaptations can be made to existing homes as well. A home’s windows, walls and floors can be designed in such a way as to absorb and distribute heat.
First, you have to have some means of collecting the sun’s heat. This is called the aperture, and consists of a large area of glass windows. Next, an absorber sits directly in the sunlight, and consists of a wall, floor, or water tank.
Behind or below the absorber is what’s known as the thermal mass. It is not directly exposed to the sunlight, but stores the heat collected by the absorber.
In a strictly passive solar home, the above three methods of distributing the heat – conduction, convection, and radiation – are the only means used. Less strictly passive homes may have fans, ducts, or other ways to move the warm air throughout the building.
In the summer, there are various means of controlling the heat so that your home does not become too hot. Shades, roof overhangs, awnings, or thermostat-controlled fans are some of the more common means of keeping the heat out in the summer.
Passive solar designs will certainly save the homeowner money; not having a heating bill to pay could save hundreds of dollars, depending on where you live. It is also eco-friendly, since it makes use of a renewable energy source (the sun) and doesn’t produce pollution.
