The Benefits of Reflective Foil

February 6, 2015
niki dube
Photo by flickr user: natural flow

Photo by flickr user: naturalflow

The benefits of reflective foil are similar to the benefits of any insulation: reduced cost and increased comfort. The differences appear in the way those benefits occur. To understand those differences you need to have a basic understanding of the way heat transfers: convection, conduction, and thermal radiation.


Convection occurs with air movement. A primary example would be the way a southerly wind usually indicates warmer temperatures in the forecast. In your home, convection occurs when you use a slow-moving ceiling fan to circulate the warmth from your fireplace.


Conduction happens when heat transfers between solid materials that are touching. An example would be a pan sitting on top of the burner on your stove. Heat transfers from the burner to the bottom of the pan to the food in the pan.

Thermal Radiation

Thermal radiation (or radiant heat) is a bit more complicated because it involves electromagnetic waves. Radiant heat is what you experience in your car on a sunny day or when you stand near the oven while baking cookies. You can feel the heat even though you’re not touching the heated surface.

How Reflective Foil Works

Reflective foil works to prevent heat transfer that occurs during thermal radiation. It does so by using a reflective barrier to prevent the heat from one side of the insulation from transferring to the other side. This reduces the radiant heat that travels through the insulation by conduction. Instead of absorbing the heat, it reflects the heat back to its source.

How does that help you, the homeowner?

Reduce Summer Heat Gain

Well, think of the sun blazing down on your roof on a hot, summer day. It heats the shingles, which transfer the heat via conduction to the under side of your roof. In most homes, the under side of the roof is an attic. Heat travels from warm to cool, so once the heat is in the attic, it “wants” to transfer via conduction through the ductwork or ceiling into your DC home. When that happens, your air conditioner has to work harder to keep your home cool. When the air conditioner works harder, you pay more to keep your home cool.

If, instead, you had a reflective barrier between the under side of your roof and the rest of the attic, that heat would be reflected instead of absorbed, keeping your ductwork and attic cooler. This means your air conditioner doesn’t have to work as hard to fight the heat transfer from the attic, saving you energy and money.

Proper Installation is Critical

In order for reflective foil to work most effectively, it needs to be properly installed. This means facing the foil properly and maintaining a pocket of air between the heat source and the reflective barrier. To ensure that your reflective foil insulation is installed properly to reduce your summer heat gain, contact the professionals at Max Insulation. Insulation is our specialty. Let us help you keep your cool, make your home comfortable year round, and save energy costs.