With winter temperatures chilling much of the country, many homeowners want to be sure their houses are sealed and insulated from the cold. But not all so-called green insulation is created the same – and while the idea of adding insulation to save energy is solid, some insulating materials are surprising unfriendly to the environment.
R-Value & Air Sealing: Cellulose, Fiberglass, & Foam Insulation
If you’re building a new home from scratch, your options are wide open. But your choices are generally a bit more limited if you want to improve the insulation in an existing home. Regardless, this excellent Green Building Advisor article outlines the key advantages and considerations for the different types of fiberglass, cellulose, and foam insulations available. One of the most important lessons: R-value is only part of the story, since effectively sealing air leaks can be just as important.
Is Spray Foam Insulation Eco-Friendly?
An insulating material that seals air leaks (even in tough to reach nooks and crannies) and also provides excellent R-value must be a good choice right? Maybe not. FourSevenFive is a high-performance building supply company in Brooklyn, NY, and a recent article on their blog makes a serious argument against foam’s green-ness.
One of the biggest issues with whole-home spray foam insulation isn’t its performance, it’s the nasty HFC/HCFC refrigerants used in blowing the foam during installation. In fact, according to an article posted by contracting/design firm Eco Brooklyn, an average foam insulation job might use 10 pounds of HFCs, whose CO2 equivalent is a whopping 7-10 tons!
Eco Brooklyn also points out that for smaller gap-filling jobs, individual cans of expanding foam sealant like Dow Great Stuff are a fine option (since they typically use other less hazardous propellants).
(title image: EPA)