On a sunny summer day, with the hot sun blasting directly on the roof, attics can get up to 140°F when the inside of the house is 75°F. In the winter, cooler air enters the house in the lower areas and attempts to exit the house in the higher — and warmer — areas.
A house with a poor and leaky envelope will show significant heat loss through the attic and eaves.
Properly insulating your home not only reduces heating and cooling costs, but also improves comfort. It really pays to have the right amount of insulation.
How Insulation Works
To understand how insulation works it helps to understand heat flow, which involves three basic mechanisms — conduction, convection, and radiation.
Conduction is the way heat moves through materials, such as when a spoon placed in a hot cup of coffee conducts heat through its handle to your hand. Convection is the way heat circulates through liquids and gases. It is the reason lighter, warmer air rises, and cooler, denser air sinks in your home. Radiant heat travels in a straight line and heats anything solid in its path that absorbs energy.
Most common insulation materials work by slowing conductive heat flow and — to a lesser extent —convective heat flow. Radiant barriers and reflective insulation systems work by reducing radiant heat gain. To be effective, the reflective surface must face an air space.
Regardless of the mechanism, heat flows from warmer to cooler until there is no longer a temperature difference. In your home, this means that in winter, heat flows directly from all heated living spaces to adjacent unheated attics, garages, basements, and even to the outdoors.
Heat flow can also move indirectly through interior ceilings, walls, and floors — wherever there is a difference in temperature. During the cooling season, heat flows from the outdoors to the interior of a house.
To maintain comfort, the heat lost in the winter must be replaced by your heating system and the heat gained in the summer must be removed by your cooling system. Properly insulating your home will decrease this heat flow by providing an effective resistance to the flow of heat.
An insulating material’s resistance to conductive heat flow is measured or rated in terms of its thermal resistance or R-value — the higher the R-value, the greater the insulating effectiveness.
The R-value depends on the type of insulation, its thickness, and its density. The R-value of some insulations also depends on temperature, aging, and moisture accumulation. When calculating the R-value of a multilayered installation, add the R-values of the individual layers.
Installing more insulation in your home increases the R-value and the resistance to heat flow. In general, increased insulation thickness will proportionally increase the R-value.
On average, you can save up to 20 percent on your home’s heating and cooling costs or up to 10 percent on its total energy costs by adding insulation to attics, floors, and crawl spaces, and by reducing unwanted air leaks all around your house.
You may be eligible for an energy tax credit when you install insulation or complete other home energy upgrades. Learn more HERE.
Customers participating in the residential EnergyWise attic insulation program are eligible for an incentive of 30¢ per square foot with a maximum incentive amount of $600 per existing residential dwelling.
The following guidelines will generally apply.
- This program is for the installation of attic insulation only. All other insulation installations (i.e. – walls, floors, crawl spaces, foundations, etc.) do not qualify.
- Only residential customers/owners qualify for the attic insulation energy efficiency incentives. Duplexes and multi-family dwellings in which each residence is individually metered are eligible for one incentive per dwelling.
- To qualify, dwellings must use electricity as the primary fuel source for heating. Customers that have air source heat pumps with natural gas or propane backup furnaces do qualify. Also, existing attic insulation levels must average six (6) inches or less and six (6) inches or more or an R-19 value of new insulation must be added to the area insulated.
- Incentives are calculated at the rate of 30¢ per square foot insulated with a maximum of $600 per dwelling.
- New construction or additions to existing dwellings do not qualify.
- An incentive will be provided to the person responsible for purchasing the insulation after the insulation is installed. No incentive(s) will be paid without the completion of the application form. The application form must then be signed by the owner and installing contractor (if applicable). The completed application form will then be submitted to the electric utility for processing. Sales receipt(s) or invoice(s) itemizing the new insulation indicating the type, amount, and purchase date must accompany each energy efficiency incentive application. Insulation must be purchased and installed on or after January 1, 2023.
Learn more about our attic insulation incentive HERE.