Though it remains invisible, hidden behind the walls, insulation is an important component of a home. It traps heat and serves as a buffer against the flow of heat from warm spaces to cooler spaces. According to the U.S. Department of Energy, homeowners use about 50% of household energy on heating and cooling. This demonstrates the importance of proper insulation, which makes homes more energy-efficient by trapping heat and keeping out the cold. Insulation quality depends on several factors, including eco-friendliness, effectiveness in insulating, safety and durability.
Cellulose insulation has several benefits. It is environmentally friendly as it is made from recycled paper. Additionally, it is considered harmless to a home's air quality, as compared to more synthetic materials such as fiberglass, which can be harmful if its fibers are breathed in. Cellulose is inserted into walls via holes drilled into the wall. Cellulose is more cost-effective than fiberglass, but has a tendency to retain moisture.
Fiberglass is produced by a chemical process that involves melting recycled glass and silica sand together. The cooled product is then fit for insulating homes. Loose-fill fiberglass is ideal for installation in small spaces since it can be blown in. Fiberglass insulation impedes adverse air flow from the outside to the interior as well as heat loss from the inside to the exterior. One drawback is that it is potentially harmful to humans if installed improperly, since this can result in the release and circulation of microscopic fiberglass particles, which are potentially harmful when inhaled.
Another insulation option is mineral wool. Required by federal regulations to be composed of at least 70% recycled material, mineral wool is an environmentally friendly option. It is composed of mineral strands from rock or recycled slag from furnaces. Mineral wool is more costly but also more durable and resistant to breakdown over time, and can effectively insulate even when it has collected moisture. Moreover, the material is flame-resistant.
Installing foam insulation is rather complex, as it requires mixing and spraying the foam into walls, attics and other desired areas. This type of insulation takes one of two forms: closed or open cell. One variety of foam insulation is polyiso, which is a foam board typically joined with a layer of foil to repel vapor. This type is flame retardant but uses minimally toxic flame retardant chemicals. It has a high R-value, which refers to the industry standard for measuring insulation performance. There are other foam board varieties, but their chemical components are more toxic and their R-value is lower, making polisyo foam a more optimal choice.