How much money can I expect to save on my utility bills if I install a radiant barrier in my attic?
Although adiant barriers BLOCK 97% of radiant heat, your utility bills savings will vary because there are other forms of heat flow in a building that contribute to the total cooling (or heating) load. Data varies by region.
Based on a radiant barrier study performed by the Tennessee Value Authority, savings averaged approximately 9% with some results found as high at 17%.
Are radiant barrier tested by qualified independent testing agencies or governmental agencies?
The Florida Solar Energy Center at Cape Canaveral has tested radiant barriers in both small scale laboratory and full scale building models. Their results indicate that radiation barriers provide significant resistance to heat transfer. Current tests conducted by the Tennessee Valley Authority and the University of Mississippi support the findings at the Florida Solar Energy Center. Northeastern Illinois University conducted winter tests in residential and commercial structures using infra-red thermograph photography. The photos showed significant resistance to heat transfer over the regular insulation.
Is a radiant barrier the same as basic kitchen foil?
Basic kitchen foil is not the same as our radiant barriers. Basic kitchen foil is comprised of approximately 22% aluminum along with other alloys and minerals that will cause the kitchen foil to break down over time. Our products are made of 99.5% pure aluminum. The higher concentrated aluminum makes our products highly reflective allowing them to BLOCK 97% of the radiant heat. Our radiant barrier foil insulation products also contain small perforations so they breathe eliminating condensation issues.
How does radiant barrier insulation work?
Radiant barrier foil insulation is unlike mass insulation that merely slows down or resists heat transfer. A radiant barrier BLOCKS radiant heat. Heat always moves to colder areas by natural law - the problem is how to keep the heat in the winter and how to keep it out in the summer. There are three ways in which heat moves from warm spaces to cold spaces: CONDUCTION is the direct heat flow through a solid object such as a wall or a ceiling. CONVECTION is heat movement through air, occurring when air is warmed. The warm expands, becoming less dense and rising. RADIATION is the movement of heat rays across air spaces from one warm object to a cooler object. The heat we feel from a wood stove or a quartz space heater is radiant heat. ALL OBJECTS AND BODIES GIVE OFF RADIANT HEAT.
Radiant barriers BLOCK radiant heat by reflecting it back towards the direction it came as well as REDUCE convective heat by acting as a blockage against convective air flow. With a radiant barrier properly installed, you can significantly reduce the amount of heat that common insulation materials are designed to slow down thereby maximizing the efficiency of common insulation materials making your living space more comfortable and reducing your overall energy utility costs.
Can a radiant barrier keep me warmer in the winter?
Just like wrapping a baked potato in aluminum foil keeps a potato warm longer by holding the heat in, installing a radiant barrier in your attic will help hold heat in the house. Another analogy would be that radiant barrier foil insulation in the winter works just like a space blanket, which, although very thin and lightweight, holds your body heat in. A thin space blanket can keep you warmer than several heavy wool blankets.
What is the "R" value of a radiant barrier?
Radiant barriers do not "absorb" heat like mass insulation (fiberglass, cellulose, foam, etc). Instead, our radiant barriers, with their highly reflective surfaces, reflect 97% of the radiant heat that hits it and therefore, have no R-value rating.
Installing a radiant barrier between the heat source (sun) and an existing R-Value rated insulation will improve the effectiveness of the R-Value rated insulation. Why? Because only 3% of the heat is now hitting the R-Value rated mass insulation giving it more time to absorb heat before becoming saturated and passing the heat into your living spaces.
Do I have to have other insulation in my attic for a radiant barrier to be effective?
No. Radiant barrier foil insulation actually makes your present insulation more effective. Installing a radiant barrier between the heat source (sun) and an existing R-Value rated insulation will improve the effectiveness of the R-Value rated insulation. Why? Because only 3% of the heat is now hitting the R-Value rated mass insulation giving it more time to absorb heat before becoming saturated and passing the heat into your living spaces.
I already have plenty of insulation in my attic. Do I really need a radiant barrier?
Regardless of how much insulation you have in your attic, adding radiant barrier foil insulation will save on your heating and cooling expense, and keep you much more comfortable. Energy savings for heating and cooling can be as much as 17%, depending on a number of factors, including climate, building configuration, materials used, site, family size and lifestyle.
A1 SUMMER: "A radiant barrier system can stop 97% of the thermal radiation across an attic space. If it is not stopped, that radiant energy would be absorbed by the ceiling insulation and eventually be transferred to the living space below." "The Solar Collector," Quarterly Newsletter of the Florida Solar Energy Center.
"The heat storage capacity of reflective insulation is low. As a result, it does not store heat during summer days, only to pass it on down into the rooms of the house from the attic at night when coolness is most apt to be desired from the point of view of sleeping comfort." "Progressive Architecture," Nov. 1949, Page 76.
A2 WINTER: "CONCLUSIONS: Reflective foil retrofitted to fiberglass insulated . . . buildings is demonstrably effective in reducing heat loss . . . Installation of foil in uninsulated buildings would show even more pronounced reduction in heat loss." "Effects of Reflective Foil On Heat Loss in Attic Floors and Metal Building Installations," Northeastern Illinois University, Prof. Charles Shabica, May 20, 1986.
Will the radiant barrier aluminum corrode over time and lose its effectiveness?
A1 "Hundreds of samples of aluminum foil have been stored in the laboratory for various periods of time up to 10 years with no visible signs of deterioration." "American Society of Heating & Air Conditioning Engineers' Journal Section."
A2 "Aluminum is highly resistant to the effect of corrosion . . . Aluminum is constantly being used where it is exposed to weather, salt spray and other conditions, which would adversely affect most metals." The United States Rubber Co. Booklet, "Serving You Through Science." Page 5.
As long as radiant barriers products are properly installed and not exposed to outdoor weather conditions, they are expected to last the lifetime of the building structure in which they are installed.
Do I need a a radiant barrier or bubble insulation for my my attic?
There is no need to purchase and install the more expensive reflective bubble insulation for your attic space as it will end up performing exactly the same as a radiant barrier which is almost 1/2 the cost. However, you certainly can install the reflective bubble insulation in your attic space but stapled to the roof decking or underside of rafters only. You cannot lay a bubble insulation product over the attic floor because it is a vapor barrier and will trap moisture that rises from your living space thereby causing condensation and potentially causing water damage in your attic space.
