Aside from taxes and legal documents, there are few subjects that might cause your eyes to glaze over faster than insulation. It’s just the stuff that goes in the wall, right? Well, there’s a lot to be gained both in comfort and money by a little extra knowledge of the subject. Every material has a specific ability to resist heat traveling through it; this is its R-value. Higher value = better insulation. Insulation can range from plain fiberglass batts (R-2.2) to high-tech aerogel based products (R-50). For the residential market, however, there are essentially three forms of insulation: flexible sheets, rigid boards, and spray or blow-in products. Rather than get too in-depth here, you can visit the DOE website for a better breakdown, or check back this week for a more complete discussion on the pros and cons of typical insulation and some of the more environmentally friendly alternatives.