Heating and Cooling
Heat pumps are electric systems that can provide both heating and cooling. They can replace a gas furnace and, where applicable, provide the cooling function of an air conditioner.
How It Works
A heat pump transfers heat from one location to another. During colder weather, it moves heat from outdoor air into the home. During warmer weather, the process reverses and moves heat from the home to the outdoors. Ducted heat pumps use a home’s existing duct system. Ductless mini-split systems mount on the wall and condition individual rooms or zones, making them an option for homes without ducts or with ducts in poor condition.
The performance and required size of a heating and cooling system depend on the home's characteristics, including insulation, air leakage, windows, and the condition of the ductwork. Ducts located in attics can be exposed to high temperatures and may develop leaks, or insulation may shift over time. Contractors determine the required system size with a heating and cooling load calculation, often called a Manual J calculation, which reflects the home's current electrical equipment usage. Sealing ducts, adding attic insulation, and sealing air leaks can reduce the required system size and your utility costs. California’s energy code requires duct testing and sealing for many equipment replacements. As much as 40% of your heating and cooling can be lost through inadequate weatherization and insulation.
Things to Keep in Mind
- Check the manufacture date on your furnace. A typical service life is 15 to 20 years.
- If your home does not have air conditioning, compare the cost of a heat pump with a new furnace plus a new air conditioner (AC), if you want AC, since a heat pump provides both.
- Consider whole-home weatherization or, at a minimum, having the ducts tested for leakage and the attic insulation checked before requesting equipment bids.
- Ask each contractor whether they performed a heating and cooling load calculation on your home, and request a copy.
- Ask your contractor whether your project requires duct testing and sealing under the state energy code.
