Saving energy in buildings becomes more important every day. A significant percentage of our nation’s energy is used to heat, cool and operate our homes and buildings. Energy lost through walls, roofs and windows is the largest single waste of energy in most buildings. Energy loss in buildings means extra operating costs, loss of comfort, and reduced productivity. When it comes to energy efficiency in buildings, plastic-based products such as rigid polyurethane foam (PUR), spray polyurethane foam, and polyisocyanurate foam insulation (PIR or polyiso) are at the center of the discussion because they are some of the most efficient thermal insulating products for buildings. They work to reduce heating and cooling loss, improving the efficiency of the building envelope.
Insulation performance is typically measured by R-value, or thermal resistance. The higher the R-value, the better the material insulates against heat transfer. PUR and PIR foams have some of the highest R-values per inch of all commercially available insulation products. With typical R-values in the range of R 3.6 to R 7.2 per inch, polyurethane products allow for energy efficient designs featuring thin walls and low profile roofs. This allows the architect or engineer to maximize the usable space in a building while reducing operating costs.
Innovative material design and technology advancements have resulted in high quality polyurethane insulation products that reduce energy loss. In a one-year study by Franklin Associates, plastic building and construction materials saved 467.2 trillion Btu’s of energy over alternative construction materials. The energy saved by using plastic building and construction materials in one year is enough to meet the average annual energy needs of 4.6 million U.S. households. In fact, the U.S Environmental Protection Agency estimates that homeowners who air seal and insulate their homes can save up to 20 percent of heating and cooling costs. Energy efficiency impacts more than just operating costs. Highly efficient walls and roofs may allow heating and cooling equipment to be downsized by as much as 35 percent. This may translate into more floor space for the same total price.
Traditional fibrous insulation products must be supported or protected by surrounding materials because of their low density. These insulation materials may be soft or sensitive to moisture, which is not the case for polyurethane insulation products. Polyurethane foam is a thermosetting insulation, providing structural performance and fire resistance. Polyurethane products have a strong yet lightweight structure, are dimensionally stable, moisture resistant and durable. This combination of properties allows manufacturers to design polyurethane thermal insulating products for many diverse applications and allows it to be attached to a wide range of substrates. In addition, when combined with the proper materials, they can perform as external air barriers, helping prevent the infiltration of outside air and the escape of indoor air.
This high performance combination is unique, encompasses a wide range of manufacturing processes, and results in thermal insulation products with multiple functions. For example, spray polyurethane foam (SPF) insulation products can be spray applied to various substrates and others can be molded to special shapes in relatively large sizes. High-density SPF has a high mechanical strength that can add rigidity to lightweight walls or roof decks. As a roof covering, high-density SPF can increase the wind uplift resistance of existing roof coverings. PIR sheathing products can practically eliminate thermal shorts and allow homeowners to get excellent value from all the insulation in the wall, which can reduce heating and cooling costs. Structural Insulating Panels (SIPS) are pre-manufactured in a variety of sizes, allowing for quick on-site assembly into a building using a minimum number of workers.