Everyone for years has known that if your home was shaded by trees that your utility bill would be greatly reduced each month. Radiant barriers work by blocking the radiant heat from the sun being absorbed by your home, office, shop, or other space. Radiant barrier simply reduces the amount of heat that your home absorbs from the sun and in doing this takes less energy to run your air conditioning to cool your home down. Less heat absorbed equals less energy needed to run the AC to counteract the heating your home gets from the sun.
If you have ever walked in front of a window reflecting light on a bright sunny day then you have experienced radiant heat. You may see the light illuminating you and your clothes, but your skin feels the heat. The heat you fell is radiant heat, radiant heat is invisible but it's there and can really raise the temperature quickly.
When it comes to your home it is much the same, the sun shines on your house and the heat is transferred and begins in the early morning heating your house and all the air pockets such as the attic and walls. This thermal heat raises the temperature of your house and return you lower the temperature using more electricity to cool down the house.
To counteract this effect you would need to plant a bunch of trees and wait 30 years or call us to install radiant barrier to block and reflect the invisible radiant heat back outside. When radiant barrier is in place it is like having a shaded house.
How much electricity would you save if your roof was shaded? This is realistically the most you will save by installing a radiant heat barrier in your attic. Nothing more, probably a little less. On a 90ºF day are you still going to run the air conditioner? Yes, it's 90°F!
After installing a radiant barrier your air conditioning will run less and more efficiently, but it will still run. However, on a 75ºF day the radiant barrier might just keep you from having to run your A/C at all. Remember, reflective foil insulation is like shade, so the more coverage you have, the better your results.
From our experience in the DFW Metroplex you can expect to save from 10% to 30% on your utility bill. Since the savings is derived from shading your home from the sun those house with larger roof areas will save the most. For example a single story ranch home has more roof area than a two story home of the same square footage so you would experience a greater savings on the single story ranch style house than the two story home.
On a two story home, you might have only half the savings compared to a single story home but you also probably only installed half the amount of foil and had a lower total installation cost. So no matter your investment, it will match your return.