Harnessing solar energy does not mean you need photovoltaic panels on your roof and technological solutions. There are many ways to design passive solar into a home that will allow you to lower your heating and cooling costs year-round, and make your home more environmentally friendly.
What is Passive Solar?
Passive solar means using the building’s windows, walls, and floors to collect, store and distribute solar energy in the form of heat in the winter, and rejecting solar energy (heat) in the summer. It is called “passive” because it does not use mechanical means to distribute heat, but rather takes advantage of natural convection, radiation, and air flow.
Is it worth it?
If you’re adding energy-efficient features into an older home (built before 1993) that currently has little insulation, less energy-efficient windows, and non-EnergyStar appliances, you may be able to reduce heating and cooling costs by up to 50-60%. That savings will pay for itself year after year, and many of the passive solar design features also add aesthetically to the house and increase the house’s market value (see “Going Green Can Add Value to Your Home”).
10 Ways To Incoprporate Passive Solar
If you are not building a new home from scratch, you may not be able to take advantage of all of the suggestions below, but, the more you can do, the more you’ll save.
- Use wide overhangs on your house to shield the house from the sun in summer. Western or eastern-facing windows are particularly vulnerable to overheating in summer, so these should be shaded using overhangs and large leaf-bearing shade trees that shed their leaves in the fall.
- Have south-facing windows that have an unobstructed view of the sun (no big trees or tall buildings in the way). Keep these windows clean and keep the drapes, blinds, or shutters open during the cooler months while the sun is shining. In the warmer months, place a removable reflective film on these windows or keep the drapes, blinds or shutters closed to block the sun. Remember: if light can get in, so can radiant heat.
- Capture and store the sun’s heat in thermal masses inside the house. This can be concrete, brick, stone, or tile which is used on walls or floors. The thermal mass absorbs heat from sunlight during the heating season, and absorbs heat from the air during cooling season. You can easily create a thermal mass by having a brick or stone fireplace which extends up the entire wall, or adding tile or decorative concrete flooring in the room containing the best sun exposure.
- Take advantage of the “chimney effect” (natural convection). Since heat rises, install operable skylights (skylights that open) in the upper-most areas of the house, such as an upper floor or vaulted ceiling.
- Use clerestory and transom windows or light tubes to let natural light in year-round, so you minimize the use of electric lights. Convert all lights in the house to LED bulbs, which radiate far less heat.
- An open floor plan takes advantage of passive solar the best, as do open stairwells and atria.
- Install EnergyStar-certified appliances and fans throughout the home, and energy-efficient double or triple glazed windows. Casement windows offer the best air flow.
- Add insulation to your attic. This will help year-round (see our post “5 of the Best HVAC Investments You Can Make”).
- Make your roof reflective with a light color paint, or by using reflective paint, shingles, or tiles. Roofs receive the majority of solar radiation delivered to a house, so a cool roof will dramatically cut air-conditioning bills.
- Allow the landscape design to work in your favor. Use evergreen hedges and shrubs as windbreaks. Use deciduous trees (trees that drop their leaves in fall) near the house, to provide shade in summer and allow light in in winter.
The real joy comes in living in an energy-efficient, eco-friendly, passive solar house that is not only beautiful, but saves you money every single day.
If you live in the Nashville or surrounding area, Interstate AC Service can help with all your heating and cooling needs. Call on us at 615-832-8500. We’re here for you!