Think about the effectiveness of some common foam products that we use on a regular basis:
The Foam Coffee Cup
Just 1/8” of foam with an R-value of less than 1!! Go to your favorite fast food restaurant or convenient store and buy a cup of coffee. Hold the foam cup in one hand and pour yourself a cup of steaming hot coffee with the other hand. Go ahead…you won’t burn your hand. The foam cup will only be warm to the touch. In fact, if the foam was a bit thicker, it is doubtful that you could feel whether the coffee was hot or cold. Only the steam would give it away. In this example, we think you’ll agree that just 1/8” of foam is a pretty effective insulator.
The Foam Picnic Chest
Just 1/2” of foam with an R-value of only about 2 This is the classic example of the insulating power of foam and a great illustration of the importance of air sealing the area you want to heat or cool. You can learn a great deal about insulating your house from its performance. You buy a foam cooler for a couple of bucks and you entrust it to keep your beverages cold for the weekend. Put in drinks and a bag of ice on Saturday morning, put the lid down tight, and it’s pretty likely that you’ll still have some ice left on Sunday night.
You have just proven the insulating power of about 1/2” of foam with a relatively low R-Value (resistance to heat flow) of only about R-2. If your house was as efficient as this foam cooler, you’d be ecstatic!
Let’s say, for example that you put in the beverages and the ice in the foam cooler above, but didn’t put the lid down tight. The ice would only last a few hours at best, and your drinks would probably be lukewarm (or hot) by mid-day Saturday. What happened? This is an extremely important question.
The R-Value didn’t change… it’s still an R-2! So why did the ice melt? Because you allowed air to leak into the cooler. The efficiency of the cooler does depend on the insulating power of the foam (it’s R-Value), but its insulating ability is somewhat irrelevant if you don’t control air infiltration.
What does this have to do with your house?
We think the same is true for your home, and we believe that your experience with a foam cooler is the most convincing argument that you should insulate your home with foam. Why? Because foam not only insulates extremely well, but will also stop air infiltration far better than fiberglass products!
Source: Green Insulation Technologies