Whether you’re a homeowner in sunny southern California, snowy central Montana, dry western Texas, or experience all four seasons in upstate New York, it’s safe to say that we’d all like to save a few bucks here and there on electrical costs whenever possible. What if it were possible to save 10% to 30% on your electrical bill no matter what climate you lived in, during both the winter and summer months. Would you take advantage of this resource? Well believe it or not there is such a solution and its a fairly simple one at that. It’s called radiant barrier, and it will make your home not only feel more comfortable but is energy efficient as well, thereby saving you money year round.
Scroll down for a video about radiant barrier installation.
What is radiant barrier?
Radiant barrier is a highly reflective material that reflects heat outwards back towards where it came from, similar to how a mirror reflects light. Usually made from aluminum foil, radiant barriers significantly reduce heat conduction – the transferring of heat passing through your roof into your home during the summer, or vise-versa, the transferring of heat from your home through your roof to the outdoors during the winter. Actually, by breaking down the name itself we can easily define what a radiant barrier is. Radiant refers to radiant heat, or heat transmitted by electromagnetic infrared waves to solid objects. The sun emits these waves on a daily basis directly to the rooftops of our homes where heat is then transferred from rooftops to attics, from attics to rooms (yes, even with proper insulation), and thereby causing our homes to increase in temperature. By installing a blockade in our attics we can interrupt this pattern of transferring heat and setup an interference in the form of a barrier. Hence the name: Radiant Barriers.
Can radiant barrier save electricity?
The main purpose of a radiant barrier is to break the path of radiant heat from the outside into the roof or attic of your home, but in reality how effective is it in blocking out that heat? You’ll be happy to know that radiant barriers reflect 97% of the radiant energy back to where it came from, 97%. This effectiveness in reducing the difference between inside and outside temperatures is important to energy savings, but it’s not the only factor. Radiant barriers reject heat from attics but attics account for less than a quarter of the total percentage of heat gain and loss in a home. Additionally, cooling and heating bills vary on the size of your home, the number of rooms and floors you have, the type of attic insulation and ventilation you have, what color your roof is, the climate, what temperature you set your thermostat at, and other varying factors. Furthermore, remember that electricity is used for more than just air conditioning and heating so energy saving costs are achieved through multiple solutions and practices. All that being said, the result of installation of radiant barriers on summer utility bills typically reduces electricity usage by 10% to 20% with increased savings in warmer climate locations. During winter months, heating bills are also reduced (although at a lower percentage than warmer months) as the radiant barrier prevents heat loss through the roof, trapping heat inside the house and reducing the need for use of a heating system.
How is a radiant barrier installed?
Depending on the your needs and how your house was built, there are two methods for installing a radiant barrier. Each method uses radiant barrier foil with perforated or naturally permeable – preferably with no form of insulation attached, that comes in industrial-sized rolls. It looks like your typical household aluminum foil, but bigger and more durable. In both cases it is best to measure and prepare the foil in a large space, or perhaps outside, in advance of installation. Beginning installation in the early morning hours will prove more advantageous to you as the temperatures in the attic dramatically increase throughout the day, so be sure to carry lots of water with you. Also be aware of lighting and the possible need to supply more lights to your work space.
Staple up installation method
If reducing the temperature not only in your house is a priority, but your attic too, then staple up installation is your best choice, especially if you have a wide open attic. The radiant heat is reflected back out through the roof before it has even has the chance to enter the attic space. This method is most efficient and best used in warm and hot climates.
Using a staple gun, the radiant barrier foil is stapled to the underside of the roof rafters. It is preferred to install the foil perpendicular to the rafters (horizontal), although the foil can be placed either horizontal or vertical, as the direction of the barrier has no effect on the performance of reflection. You may work from bottom up, or from top down, but in either case there should be no more than 2 inches of overlap on each row. Be sure to cut out holes for air vents, bracing, and other obstacles to allow air flow and access to desired needs.
Over insulation installation method
An easier method of installing your radiant barrier is to place it directly on top of your already existing attic insulation. Although this won’t reduce the temperature of your attic space, it will still reflect the radiant heat driven in through your roof. This method is best used in cold or mixed climates as it minimizes the radiant heat entering your home and minimizes the airflow in your insulation thereby making your regular insulation more effective during the cooler months.
Using an already prepared installation tool- a furring strip with a nail attached to the end of it is recommended of two or three varying lengths. Start in the far corner in one end of your attic and roll out the barrier across attic floor joists. Continue covering the attic floor, overlapping the foil sheets no more than 2 inches. While it’s not necessary to use staples small pieces of foil tape to attach the pieces together with help with the installation process. When installing do not push the foil down into the attic insulation. It is more effective with a couple of inches of air space. It is also not necessary to make the foil look perfect. Waves, creases, peaks and valleys are a natural part of the installation and will not affect the reflectivity effectiveness. Be sure to cut around any appliances, electrical boxes, vents, supports, braces, or other obstacles that would otherwise be covered by the radiant barrier.
What are the advantages of radiant barrier?
Well for starters, lower energy costs. As mentioned, your electric bill in the summer and your heating bill in the winter could be reduced between 10% to 30%. With the staple up installation method, attic temperatures decrease by 20 to 35 degrees in the summer. With the over attic insulation installation method your current insulation becomes more effective because the radiant barrier complements the existing insulation.
Because of its inorganic material, radiant barriers do not support rodents, birds, or insects. Its material makeup also means that there are no harmful particles that will be emitted from it. It’s non toxic and non carcinogenic. Aluminum foil is highly resistant to corrosion and therefore takes decades before visible signs of deterioration are seen. Additionally, it will not mold or mildew.
Installation of the radiant barrier is clean, easy to handle, and lightweight, and requires no special tools or clothing. Radiant barriers require little to no maintenance. It may increase the resale value of your home due to significant improvements in your energy bill. And it helps conserve energy and therefore helps the environment by reducing unnecessary gas emissions from overuse of heating and cooling systems.
If you are seriously considering radiant barrier for your home, here is a short video summarizing the installation process from an actual radiant barrier installer who has an entire library of YouTube videos on the topic.