Although you may have spent the last few months figuring out how to keep your home warm, summer is fast approaching and it is now time to try and keep it cool. One of the most cost-effective ways for staying cool in the summer is to utilize passive solar design. And guess what? Doing so can also help you stay warm during the winter.
Passive Solar Principles By Master Builders
How to keep your home cool by passive solar cooling
Passive solar design involves using the sun to heat a building during the winter while blocking the sun out during the hotter months to keep it cooler. While these techniques can be used in conjunction with solar power, they do not need to be. Rather, the techniques of passive solar cooling focus more on how the home is built and used.
To keep a home cool during the summer, south-facing windows should be covered during the day. To keep the sun from shining through the windows and thereby heating indoor surfaces, use blinds, shutters, curtains, and/or sun block window films. Awnings are also great during the summer months when the sun is high in the sky (during the winter, the sun is at a lower angle in the sky and can still shine through the window). At night, when it is cool outside, the window coverings can be opened. Avoid having west facing windows.
Another way to keep the sun out is by having deciduous trees or bushes in front of the south sides of buildings (these can be helpful, even if you do not have any south-facing windows.) The added benefit of deciduous trees is that they have lost their leaves by wintertime, meaning that the sun can be allowed to shine through your home and heat the interior surfaces.
Another method of heating and cooling a home is called direct gain. Direct Gain involves having good thermal mass in the room. Dense and heavy materials like stone floor slabs or concrete walls, masonry materials are generally best. Because they absorb and release heat slowly. But any material in the home, including furniture, that absorbs and stores heat is considered thermal mass. The best thermal mass is that which is located in direct sunlight and of a dark color.
During the cold months, the sun shines through the window and heats the thermal mass, and the thermal mass heats thereby heats the room. During the warm months, you can prevent the thermal mass from receiving sunlight by keeping the blinds closed, etc. At night, the thermal mass cools down and stores this coolness and slowly releases it throughout the next day.
Ventilation is another important way of passive solar cooling that is being incorporated into buildings to lessen the costs (monetary and environmental) or air conditioning. Vents in upper levels of buildings allow warm air to rise by natural convection and flow to the outside. In connection with this, cool air can be drawn into a room through lower level vents.
Solar chimneys are also being implemented in some newer “green” homes to provide ventilation. A solar chimney is a vertical shaft which the sun heats during the day (including the air within it). This causes and updraft of air. Suction is created at the base of the chimney, drawing cool air in, thereby cooling the building.
Instead of simply turning up the air conditioning. Look for other more economical and more environmental ways to cool your home.