Insulation South Burlington VT
St. George, VT
Essex Junction, VT
Home Renovation, Interior Painting, Drainage Systems, Foundation Repair, General Contractor
Years in Business
Essex Junction, VT
Insulation Choices and Strategies - Zero Energy Homes
Insulation levels throughout the house are where zero energy buildings diverge from conventional energy code requirements most dramatically. To reduce net energy use to zero, houses need significantly higher insulation levels than conventional buildings that rely on abundant and inexpensive fossil fuels.How Much Insulation is Appropriate
It depends on climate. The real issue is now to get the heating and cooling loads so low that a homeowner could heat the house with the refrigerator, a computer or two, and the dogs. Low heating and cooling loads are the magic bullet that allows zero energy houses to be cost-effective in any climate.
Insulation types and location determine how well the home will perform through the diversity of climate conditions and future challenges. For example, using spray foam to air-seal the house makes subsequent insulation strategies easier than trying to air-seal the house with just fiberglass.
Note: Fiberglass insulation that is installed over a couple of inches of spray foam is one way to make the house airtight and still affordable.Types of Insulation
Insulation R-Value Quick Chart
Conventional installation of fiberglass doesn't yield the performance required for a zero energy house. Typically, fiberglass is stuffed into wall cavities without regard for wiring, plumbing, or other obstacles already installed. Fiberglass requires conscientious air sealing before installation:All vertical and horizontal penetrations from the envelope need to be foamed to prevent air movement Attic/second floor connection requires perfect air sealing because fiberglass itself does very little to resist air movement Batts must be cut around every wire, electrical box, and pipe in the wall
Cotton batts are made from recycled materials. To work effectively, they require perfect installation around all obstacles in a wall cavity. The material is very difficult to cut: use an electric knife and a manual hedge trimmer for straight cuts.
Cellulose insulation has a high recycled content and is more affordable than foam. Make sure to use only borate-treated cellulose, as any moisture that gets into ammonium sulfate-treated cellulose will cause it to off-gas ammonia.
Note: It is recommended that you use a professional to install cellulose.
Cellulose can be installed two ways:
Dry as loose fill in wall and is kept in place behind netting. But be careful. Too dense, it fills out the netting and makes drywall difficult, if not impossible to install.
Sprayed on. It is mixed with an acrylic binder that holds it firmly in the wall cav...
Interior Versus Exterior Insulation
What are the advantage and disadvantage of interior and exterior insulation. Review the list below to learn more and decide which strategy is right for your project.Interior Insulation
AdvantagesIt is simpler to install on existing foundation walls. Material costs may be low since you can use almost an insulation material.
DisadvantagesMany types of insulation require separation from habitable spaces by a fire-resistant material, since they are often extremely flammable and will release toxic gases if ignited. It reduces usable interior space when retrofitted. It fails to protect the waterproofing membrane. It may become saturated by moisture. Exterior Insulation
AdvantagesIt minimizes heat loss through the foundation. It protects waterproofing membrane. It can serve as a capillary break to block moisture infiltration. It prevents freeze-thaw cycle damage to foundation. it reduces interior moisture. It does not reduce usable interior space when retrofitted.
DisadvantagesInstallation is more difficult than interior insulation in retrofits. Material cost is higher. Some exterior insulation materials are susceptible to insect infestation.