Uh-oh. Turns out that many of the insulation materials we use to reduce our energy use (and thus reduce greenhouse gas emissions), are themselves producers of extremely potent greenhouse gases. How bad? Try up to 1,430 times.
Because it is made of hydrofluorocarbons, the worst insulation material is extruded polystyrene, (like in Dow Styrofoam or blueboard, and Owens Corning Foamular or pinkboard), which has a global warming potential (GWP) of 1,430 times that of carbon dioxide. It has R-5 insulating properties.
Spray polyurethane foam, typically air-sprayed into building cavities, onto a foundation walls, or onto roofs, has an R-6 insulating value, so it has slightly more insulation bang for the buck paid to future climates, because its global warming potential (GWP) is only 1,030 times that of CO2. But safer would be to use the water-blown kind of spray polyeurethane.
In the June issue of Environmental Building News John Straube and Daniel Bergey of Building Science Corporation join with Building Green to analyze in depth the cost/benefit ratio, including how much actually leaks out during a building’s typical 50 to 100 year lifetime versus how much fossil energy is not used to keep the house warm or cooled in that time.
Bookmark it to check out the pros and cons before you retrofit.
Source: Building Green