Radiant barriers are materials installed into a home during the insulation process to prevent the conduction of heat. They help to maintain temperatures in your home, year-round but are of particular importance in the heat of summer. A radiant barrier- in the short version- is a shiny, flexible material used to slow heat transfer.
How Heat Travels
Heat travels from a warm area to a cooler area by way of conduction, convection, and radiation. Conduction happens when heat transfers location through a material, such as your home’s walls or roof. Convection is the transfer of heat through a liquid or gas, such as when the air is warmed, it becomes less dense and rises. When air is cooled, it becomes denser and sinks. Radiant heat transfer is when heat travels in a straight line away from any surface and heats anything solid that absorbs its energy such as your countertops and furniture when the sun shines through a window. Previous articles have discussed how to either harness these powers for passive solar heating or to reduce them from happening for passive solar cooling.
How Radiant Barriers Work
Insulation works by slowing conductive heat flow through the home’s walls. To a lesser extent, it also helps reduce some of the convective heat flow. Radiant barriers work by reflecting radiant heat away from the home.Radiant barriers consist of highly reflective materials, such as aluminum foil. It can be combined with many types of insulation materials as a facing material. A radiant barrier works the best when it is installed perpendicular to the radiant energy that strikes it, which is why it is much more effective when installed in an attic than a standing wall. Radiant barriers work almost completely opposite than solar panels, which are installed perpendicular to absorb solar power.
Think of radiant barriers as Thermos mugs, that help maintains the temperature of whatever is inside the mug, regardless of the external temperature. In the summer heat, radiant barriers reflect solar heat away from a home before the insulation and building material have a chance to heat up. Conversely, in the cold winter months, it acts a space blanket, keeping the warmth from escaping by being cooled when your walls absorb the external temperature.
How Radiant Barriers Affect Home Energy
Radiant barriers can reflect up to 97 percent of solar radiation. Research has shown that radiant barriers can reduce summer ceiling heat by 16 to 42 percent. Since the ceiling heat gains represent between 15 and 25 percent of the total cooling of the home. This means that there is an expected, overall, two to ten percent reduction in cooling summer home energy costs in warm climates. Bear in mind, in colder climates, radiant barriers may have as little as one percent reduction in summer cooling energy costs.
If you are concerned about your home energy usage or if your home has trouble maintaining a comfortable temperature without your heating or cooling system constantly running, call us at Apex Home Energy Savings. We specialize in home energy and can perform a home energy audit on your house to see where its strengths and weaknesses are. Call us today!