Having a well insulated and air-sealed home is essential to comfort, affordability, and sustainability. When our Home Energy Performance Division conducts home energy audits, the insulation and air-sealing of most homes are often found to be seriously insufficient. Efficiency improvements like insulation are typically the most cost effective way to reduce energy usage and costs, and improve the comfort and safety of your home. They are also necessary if you want to consider renewable heating systems in the future.

Types of Insulation

Not all insulations are created equal. Traditional insulations like fiberglass actually allow air to pass through them quite easily, and are given their R-value rating in a 70 degree-no wind test environment, which is very different from the real world. In our experience, we have found spray foam insulations to be the most effective at stopping air infiltration and providing a good conductive and convective barrier.

Fiberglass

This is the most common insulation and the  least effective. The R-value of any fiberglass product should be down-rated to its actual effective R value when air movement is take into account.

Cellulose

This is another common insulation, especially for walls and attic flats. It, however, is also not a very effective air barrier, and also tends to shift once in place, especially if not dense packed and in walls. Like fiberglass, but not to the same extreme, the R-value of cellulose should be down-rated to calculate its actual effective R-value. The most effective form of cellulose if it must be used, is high-density cellulose when blown into a wall cavity.

Sprayfoam

We have found spray foam to be the best insulation for most applications. There are several type of spray foams, and they are primary categorized by chemical composition, density, and cell structure type (which affects rigidity and moisture properties). We have had excellent experience with the Demilec products, including the Heatlok Soy closed-cell 2 lb foam and the Sealection Agribalance open-cell 0.7lb foam, as well as the Air Krete cementitious foam product, which is designed especially for retrofitting existing wall cavities.

Types of Spray Foam

• Polyurethane vs Urethane Polystyrene Polyisocyanurate Polyicynene (Longevity, Indoor Air Quality)
• Closed Cell vs Open Cell (Interaction with Water, Rigidity)
• Density (Rigidity)