BY PAT KEEGAN AND BRAD THIESSEN
An electric air source heat pump can be a good alternative to a furnace system that runs on propane or fuel oil. A heat pump is also a cost-effective alternative to electric resistance heat that’s used in electric furnaces, baseboard heaters and wall units.
Do you know how a heat pump works?
In the summer, an air source heat pump acts as an air conditioner that draws heat from your home’s air and transfers it outside. In the winter, the system’s direction is reversed, so heat is pulled from the outside air and moved into your home.
The heat pump has two major components: the condenser (also called the compressor) outside that circulates refrigerant through the system, and an air handler inside that distributes the conditioned air. Heat pumps distribute the hot or cold air through your home’s duct system.
In the past, heat pumps weren’t efficient enough to work in colder climates. In recent years, however, technology has advanced to make them viable in climates with long periods of sub-freezing temperatures, such as Iowa.
If your old furnace has an air conditioner attached, replacing both the heating and cooling system with the all-in-one solution of a heat pump could produce significant cost savings. If you’re currently cooling with window units, or have an older central air conditioner, moving to an air source heat pump could reduce your summer energy bills.
Heat pumps not only reduce energy costs, they can also eliminate the risk of carbon monoxide poisoning and problems that can occur with onsite storage of propane or heating oil.
The downside of using a heat pump – and it’s a much less significant problem than it was when heat pumps first came on the scene many years ago – is that a heat pump must work harder to extract heat as the outside temperature drops. At some point the heat pump switches to resistance mode, which operates the same way a toaster or an electric baseboard heater works.
Here’s what to look for
The ratings on a heat pump make a big difference in efficiency, and in Iowa you’ll need to consider both heating and cooling ratings. For heating efficiency, look for a unit with a high HSPF rating. On the cooling side, focus on the SEER rating, which measures cooling efficiency.
A basic standard heat pump is rated at HSPF 8.2 and SEER 14, but that kind of efficiency won’t have a big impact on your power bill. Instead, look for a heat pump that’s Energy Star® rated, which means it has a ratings of at least 8.5 HSPF and 15 SEER. If your budget allows, consider a top-of the line heat pump like the Carrier Infinity unit shown here; with an HSPF up to 13 and a SEER up to 20.5, it’s one of stingiest users of electricity on the market.
Visit touchstoneenergy.com, energystar.gov or your local co-op’s website to learn more about equipment, installation and qualified contractors. Also be sure to check into state and co-op rebates.
This column was co-written by Pat Keegan and Brad Thiessen of Collaborative Efficiency.