You're familiar with traditional fiberglass insulation – it's itchy, looks like cotton candy, and keeps hot or cold air from entering or exiting your home by absorbing and retaining it – rather than by reflecting the air back in the direction it originated from.
The only characteristic that this traditional insulation has in common with the newer foil insulation is it's insulating quality.
You've been using the same basic concept behind foil insulation in your kitchen for several years. When you cook a dish and want to keep it warm until it is served, you often cover it with aluminum foil, which prevents the heat from escaping by reflecting it back down onto the dish.
Foil insulation is made up of layers of aluminum foil, air bubbles, and wadding. And like the aluminum foil in your kitchen, it works by reflecting radiant heat. It is most often used in attics, where it can reflect the heat back out of your attic – either back outside or back down into your home. According to estimates by manufacturers, it reflects up to 97 percent of radiant heat, which can cut your heating and cooling bills by up to 25 percent – if it is installed correctly.
If you choose to install foil insulation in your home, there are a few things to take into consideration.
1. Location. It will provide the most benefit when it's placed close to the heat source. As most heat will enter your house through the roof, foil insulation will be most effective if it's installed on the inside of the roof tresses or rafters. It can also be installed on top of the previous insulation on your attic floor.
2. Moisture. Traditional fiberglass insulation absorbs moisture. Foil insulation is impenetrable and therefore can allow moisture to build up underneath it. To prevent this, ensure that you get perforated foil insulation so that moisture can not build up. In addition, leaving a gap at both the bottom and top of the trusses allows air to easily circulate on both sides of the reflective foil, which further any water vapor to escape the house via roof ridge vents or wind-powered turbine vents.
3. Seal. When you install foil insulation as a house wrap, you should ensure that you can get a tight seal. When you properly install the foil and make sure it has a tight seal, this ensures that the foil can act as a barrier against air transfer and drastically reduce drafting in your house.
Insulation Foil may not be the traditional method of insulating. However, it provides many benefits that traditional fiberglass insulation does not – including recyclability and providing a greater savings in heating and cooling costs.