Radiant Barrier Insulation is a reflective insulation made mostly out of aluminum. There are lots of different types radiant barrier out there and they all have their specific applications. I know mostly about radiant barrier that is used to retrofit existing homes, specifically adding the insulation to the attic.
There are some radiant barrier types that are used in new constructions which are placed in the walls or under concrete etc but again, I’m focusing mainly on the addition of the material to an existing home on top of the existing attic insulation. When radiant barrier is rolled out on top o the existing attic insulation people can expect so see an average of 17% reduction in their heating and cooling costs.
Some people even claim as much as a 50% reduction in their monthly bills but that’s more of an extreme case. The difference comes in how you use your electricity and/or natural gas. If you have an enormous house with giant vaulted ceilings and live in Arizona and like to keep your house at 65 degrees Fahrenheit during the summer then adding radiant barrier might actually save you 50% or so.
But if you have a really small house and you live in a moderate climate and most of your electricity is used for your 5 giant plasma TV’s and you only turn the air conditioner on once or twice a summer, then you probably won’t see that large of a reduction in your utilities bills. Whether or not you see a reduction in your utilities bills you will most certainly be able to maintain a comfortable temperature in your house much more easily than with only the standard mass insulation (fiberglass, cellulose, styrofoam etc).
The most cost effective way to install the radiant barrier insulation into your attic is to simply lay it on top of the existing insulation. If you’re going to do this just make sure that you use material that allows water vapor to pass through it so you don’t have any moisture condensation problems. And just follow the directions provided to you by the manufacturer. If the manufacturer doesn’t provide instructions then you should choose a different manufacturer. If you’re going to hire someone to do it then make sure they are bonded and insured so that if they fall through your roof you won’t be stuck with the bill.