Insulation helps maintain thermal comfort in a home and contributes to energy efficiency by slowing down the heat transfer between the exterior and interior of a building. Insulation is typically used in floors, walls and ceilings.
Insulation is effective in stopping three forms of heat transfer: Radiation, Conduction and Convection. This resistance to heat flow is measured by R-Value. The areas in a home most commonly insulated are the Building Envelope: The Building Envelope (also Thermal Envelope) is the “skin” of a home. A major factor in the energy efficiency of the home, the building envelope is responsible for protection from the outside elements and moisture control. It consists of the structural materials and finishes that separate the inside of the home from the outside, including windows, walls, doors, roofs and foundations (Yudelson). Sometimes Interior Walls and ceilings are insulated, when there is separation between housing units (multi-family) or when there is need for soundproofing.
Some common insulation types are:
Batt – Batt insulation, the most common insulation used in homes, fits between studs or other framing. Batts are made of fiberglass or mineral wool and installed with or without a paper backing on one side that serves as a vapor retarder to control moisture. Batt insulation is easy to install, affordable and widely available.
Spray Foam – Spray foam is a two-component mixture sprayed into a cavity or surface. The mixture comes together and expands forming the foam insulation. It is effective in hard to reach or overhead areas. Most spray foams are made of polyurethane in two forms, open and closed cell which have different heat and moisture resistance properties. Spray foam insulation requires a trained contractor to install and typically has higher upfront costs than batt insulation.
Blown In – Blown in insulation is made of fibers, typically fiberglass, mineral wool or cellulose and often contain recycled content. The fibers are blown into wall cavities or attic spaces and can effectively fill voids in odd shaped cavities. Blown in insulation works well in home renovations as it can be applied to existing walls without having to deconstruct them.
Many alternative types of insulation are being made available. Materials vary from recycled jeans and sheep’s wool to highly engineered materials like Aerogel.
All of these insulation types have different environmental benefits and thermal resistance levels but are used less as they lack widespread availability, are usually higher cost and have not had long term testing in homes.
Make It Right has used batt, spray foam and recycled denim insulation on various homes across all our affordable building projects.
Insulation and sealing are important factors in achieving energy efficiency. High insulation values, coupled with correctly installed, argon-filled Low E windows allow our homes to have tight envelopes. This reduces the amount of energy our homes use to keep cool or warm.
Because our building envelope is so tight, we must ensure that the products and materials inside the home do not Off Gas The evaporation or emission of volatile chemicals at ambient atmostpheric pressure. Building materials such as paints, stains, sealants, varnishes, carpet, insulation, flooring, kitchen cabinets, countertops, plywood, particleboard and paint strippers can release chemicals into the air causing poor indoor air quality. (Yudelson) carcinogenic fumes. We use Cradle to Cradle certified carpet and countertops and zero VOC Gases that evaporate from building materials and home products, such as adhesives, sealants, paints, varnishes, carpet, furnishings, office equipment and upholstery. Can cause acute and chronic illnesses and lead to poor indoor air quality. (Yudelson) paint to maintain high indoor air quality.