Shutter insulation – Insulation is rated on its ability to insulate cold and warm from the exterior to interior. The rating used is based on an R-value rating. The higher the R-value the more insulated the product.
Attic space is R-19 to R-38,
Walls are R-13
Windows are only R-3.5
That is a high number when you realize it is the number for a brand new manufactured double or triple paned window. Unfortunately, the argon gas they sale you on between these windows disappears at nearly 9% per year which means by year 10, you have nearly lost all of your argon gas, which means it is time to buy a new window even though the window doesn’t have a single Crack in it.
When you add wood shutters, you add an additional R-3 to R-4 to your windows. That is right you will be around an R-6 to an R-8, nearly the insulation value of your wall. Here is the best thing wood does not dissipate, wood doesn’t slowly lose insulating value and require replacement. Shutters are a logical, sustainable, insulating product. It doesn’t only help the earth, it helps your wallet.