One of the main enemies of home energy efficiency is the hot summer sun. Unimpeded, sunlight is applying about a kilowatt of energy per square meter. As you can imagine, it only takes a little direct sunlight coming in through the windows or glass doors to really make a big difference in your air conditioning bills. The average air conditioner uses about 6 kilowatts of energy, which means with just 3 south facing windows you may be using up half it’s capacity!
One way to counteract the heating effect of the sun’s rays is to block it with drapes and curtains. Various styles and designs of homes will have different window treatments that go with the decor. For instance, a balloon shade goes great with traditional country or ranch style homes. Whereas sheer blinds may go better with contemporary or modern house decor.
The problem with relying on curtains and shades for keeping the sun out is they don’t really keep the sun out at all. Instead, the sunlight is entering in through the window, where it is then blocked. Because of this, much of the heat is kept inside the home, even though the glare of the sun has been dealt with.
A better way to accomplish passive cooling of your home is to provide the shade outside the windows. Window awnings are great for this purpose, but may not fit with every home’s exterior decor. Some additions to the house can look great, but aren’t really that useful for providing shade.
The traditional pergola is a good example of this. There are however pergolas that can do a great job of this though. For instance, a metal pergola with canopy will allow you to block the sunlight when you don’t wan the heat, and then retract the canopy when you want the light (such as in the winter). This way you enjoy the best of both worlds, cool shade in summer, and warming sunlight in winter.