Cooling

Here are some ways to reduce heat gain in the summer:

• Properly place and orient your building on the building site. This alone can make a huge difference in the heating and cooling needs of your home. By correctly orienting your home, you can take advantage of the natural elements on your building site.
• Properly place windows. For example, limiting the number of West facing windows greatly reduces heat gain in the summer. South facing windows let in light and heat in the winter.
• Design your home with larger overhangs on windows which create shade in the Summer but allow sunlight when you want it in the Winter. If you are retrofitting your existing home, you can use awnings or plant trellises to shade your windows. This can significantly reduce your need for cooling because about half of the heat gain in buildings in the Summer comes from unshaded windows.

• If its appropriate to the aesthetics of your home, you can plant vines or ivy that will grow on your home (especially on the West and South sides). This keeps your home cool in the summer but will not block the heat from the sun in the Winter when the plants die.
• Plant deciduous trees near your home. Trees are the Earths greatest temperature regulators. The typical home takes three tons of air conditioning to cool and each large tree is equal to approximately one ton of air conditioning. In the cooler months you are still able to take advantage of sunlight and heat gain because all of the leaves have fallen.

• Reduce the amount of concrete surrounding your home. Concrete absorbs and radiates the heat from the sun which raises the air temperature and increases your cooling load.

Here are some alternative ways to cool your home:

• Geothermal Earth Tubes: Have you ever noticed that the basement is always cooler than the rest of your home? This is because the earth's subterranean temperature is a approximately 55 degrees year round. Geothermal Earth Tubes are a way of taking advantage of the earths temperature to precondition the air entering your home by putting tubes in the ground that circulate air through your home. In the Iowa summer when it is 100 degrees outside, you can bring cool air in from underground. This air enters your home at about 70 degrees and mixes with the existing air to give you a temperature of approximately 80 degrees. You can keep your home nice and cool if you combine this technology with the methods for reducing heat gain that are given above. Earth Tubes are not only useful in the summer. In the winter, when the temperature is far below 55 degrees, you can raise the temperature in your home which reduces the heating load. For more information on Earth Tubes check out Links and Resources.
• Green Roofs: A green roof is simply covering your existing roof either partially or completely with light-weight soil and plants. It also includes a waterproof and root repellent layer, drainage layer, and filter membrane. Green Roofs are aesthetically beautiful and can lower your cooling load by up to 25%. As well as reducing the need for air conditioning, roof gardens have a number of other benefits:
  • Storm and sewer relief through water retention
  • Diminishing the urban heat island effect
  • Air purification
  • Water filtration
  • Improved insulation

• Super-insulation: Super-insulation techniques include R-40 insulation in the walls, R-60 insulation in the roof, and air-tight construction. This allows you to fully utilize the energy in your home. See the section on Efficiency for more information.