It is very common to have interior window treatments that are there for privacy and to add to the décor. Many people use blinds, drapes and shades as a way to keep the heat inside in the winter and prevent the sun from heating the house in the summer. The right type of window treatments can save a significant amount of money on your heating and cooling expenses. Once you understand how the heat from the sun can heat your home, you will understand why you need exterior sun screens to save the most energy.
Radiation from the Sun
Sunlight hits the walls and windows of your home by short and long waves of radiation. The material in the walls can stop the penetration of the radiation, but the glass in the windows cannot stop the short waves. Any sunlight that streams in through a window will heat up anything it touches. Once heated, the air surrounding them will absorb the heat.
Interior Window Treatments
When you put up blinds or heavy drapes designed to reflect sunlight on the inside of a window, there is a gap between them and the glass. The sunlight penetrates through the glass and into your home. The window treatment will reflect the waves back toward the glass, but reflection changes the short waves into long waves that cannot pass back through the glass. Instead, they heat up the glass. The heated glass then heats the surrounding window frames and allows the heat to transfer to the air in our home.
External Window Treatments
Using External solar screens stops the short waves from entering your home. Instead, they are reflected back into the air outside. Your home will not be heated by the sun's rays and your cooling bill will be lower. In addition, the screens will prevent heat loss from your home in the winter. As the sunlight hits the sunscreen and bounces back through it, the screen itself remains warm. Any heat that penetrates through the glass of the window from inside the house is not needed to heat the screen and is reflected back to heat the glass. This will then create a pocket of warm air and stop any further heat transfer.
Of course it is always a good idea to have some type of interior window treatment that you can open to allow in light but not heat and then to close in the evening to maintain privacy. However, if you are looking for a way to reduce your heating and cooling bills, add external sun screens to the windows too. To do so, contact professional providers, such as Desert Shutters and Shades / Solar Screens.