David Zalubowski/AP
As electric vehicles and solar energy panels become more common, heat pumps are another step on the road to “beneficial electrification.”
- Heat pumps aren’t really furnaces, but can heat buildings. They aren’t air conditioners, but can cool a building. Those pumps have compressors that exchange indoor and outdoor air. According to an explainer in Popular Mechanics, heat pumps in the winter take outside air and heat it with the compressor, providing heat to an interior space. In the summer, the compressor absorbs heat from inside a building and releases it outdoors.
According to Nikki Maline, the Energy Programs director at Walking Mountains Science Center, those units in the winter are three times more efficient than electric baseboard heat.
Maline said about 35 local homeowners this year will take advantage of various rebate programs to install heat pump units.
Maline said Holy Cross Energy has “very generous” rebates and tax credits available.
Depending on where a building is, those rebates can make heat pumps “worth considering,” Maline said.
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Those units come with a pretty significant caveat: Efficiency plummets as temperatures drop. Maline said technological improvements have made cold weather-rated units more efficient in colder climates. Still, she said, many systems installed locally have various kinds of backups, ranging from electric heating units to keeping an old gas furnace on hand.
Already in use
Eagle County has already installed heat pumps at its vehicle maintenance facility in Gypsum. County Facilities Director Jesse Meryhew said those units, mounted on the roof of the south side of the building, heat and cool the offices on that side of the building.
Just as important, the units can move heated and cooled air to various parts of that building, including the computer room, which needs to be held at a constant, cool temperature. It can also cool offices with south-facing windows.
The system, installed fairly recently, “seems to be working well so far,” Meryhew said.
That building is the first county facility to use heat pump technology, but may not be the last. County officials are looking into the prospect of using a different kind of heat pump — called “ground source” — for the county administration building in Eagle. That system uses geothermal heat from inside the earth to fuel the air exchanges.
But ground source heat pumps are expensive. Meryhew said a ground source system for the county building will require a still-to-be determined number of boreholes, all of which are six inches in diameter and between 400 and 500 feet deep, spaced roughly 20 feet apart.
Energy consultant David Petroy said ground source applications are worthwhile for government buildings, schools, hospitals and large homes. Petroy noted that the gigantic Ikea building in Centennial uses ground-source heat pumps.
Petroy said part of the expense is the limited number of firms that can drill holes that deep.
But, Meryhew said, once the holes are drilled, the basics of the system beyond the hardware can last for 100 years or more. The units that use the geothermal energy are relatively easy to swap out, and tend to be easier to service than conventional boilers.
The engineering isn’t finished yet, but it’s possible that ground source heat pumps will be used on a new county facility in Edwards, roughly between the Mountain Recreation field house and the Colorado Mountain College building.
Some of the county’s older buildings could be good candidates for heat pump conversions.
All about efficiency
The idea, of course, is efficiency and a transition to a greener energy environment.
“People are saying ‘what can I do,” and are becoming aware of heat pumps, Petroy said.
Petroy added that people building new homes should consider a heat pump system, along with rebates and tax credits. Those replacing their current heating or cooling units may have a bit more math to do before making a decision.
As just a furnace, a heat pump will cost more, depending on rebates. But, Petroy added, just about anyone who’s replacing a central air conditioning unit should replace that device with a heat pump.
While an air conditioner is used for about three months in Colorado, a heat pump can be a three-season device.
“A heat pump can still do a lot with a furnace supplement,” he said.
Heat pumps can help insulate users from variable natural gas prices. Maline said heat pumps can make even more sense in rural areas in which homeowners rely on propane. Prices for that fuel can be “very expensive,” she said.
The Dotsero mobile home park runs off propane. Walking Mountains has helped with heat pump installation in that area.
But, Maline added, rebates can make a big difference in the decision. Rebates can be available for households earning up to 150% of the area median income. In Eagle County, that’s an annual income of up to $177,000 for a four-person household.
“It can work for people,” she said.