Geothermal heat pumps deliver ultra-efficient heating and cooling, but they still feel out of reach for many homeowners, either because of their cost or because they may be too difficult to add to a home.

Here's what to know

After installing an air-source heat pump and saying they "absolutely love it," the homeowner turned to Reddit to ask whether geothermal systems justify their upfront expense. Users in Colorado, Michigan, Arizona, and Massachusetts responded to the original poster.

In the OP's words, the trade-off is straightforward: "It's supposed to be way more efficient to run… and expensive to install." 

The Reddit discussion showed how uneven the real-world math can be: one Colorado resident said their system cost $50,000 before incentives (and $24,000 after), but now they pay nothing for AC.

For the Colorado owner, comfort mattered as much as efficiency. They wrote, "Cooling is almost free. Heating is about on par with natural gas," and said the variable-speed equipment was much quieter than the 80%-efficient single-stage furnace it replaced.

Not every comment pointed in the same direction. A resident of Western Massachusetts said 2022 quotes ran $40,000 to $60,000 and did not look likely to deliver meaningful savings over municipal electricity plus natural gas, while a Michigan homeowner said a $20,000 WaterFurnace system ($14,000 after incentives) has had "No issues in 15 years, just minor maintenance."

More background

Posters from hotter climates highlighted the limits of simple payback comparisons. In Southern Arizona, one homeowner said a 5-ton horizontal loop system buried 8 to 9 feet down performed well early in the summer but later ran "nearly 24hrs a day" once the harsher heat set in.

In that Arizona setup, loop temperatures reportedly climbed above 100 degrees Fahrenheit, prompting the owner to add loop pumps and heat exchangers and to consider drilling vertical wells later. 

Another commenter described a geothermal system that was easier to justify because it went into a new two-story home: the house uses two units connected to six wells, each 150 feet deep, and the drilling cost about $10,000. They also noted that retrofits can be tougher because wells have to be placed around existing water, sewer, and gas lines.

What can be done?

Homeowners need to match the system to the property, the climate, and the household's energy use before committing. While some commenters praised horizontal loops as the cheaper option, the Arizona example showed how quickly soil moisture and extreme heat can affect performance.

For homeowners weighing that kind of upgrade, Palmetto can help homeowners understand their HVAC options and reduce their energy bills with newer, more efficient HVACs and heat pumps, while its Comfort Plan network can help connect them with vetted installers.

For homeowners who are not ready to spend heavily up front, Palmetto says its Comfort Plan includes $0-down HVAC subscription options that can lower heating and cooling costs by up to 50%. Palmetto Comfort Plans also include 12 years of free maintenance.

Where can I learn more?

If you're sizing up geothermal against other HVAC upgrades, these stories show why the math can look so different from one home to the next. 

• Across U.S. homes, geothermal heat pumps have lowered utility bills despite steep upfront costs.

• In Colorado, Eagle County says utility costs will fall after a $15 million geothermal investment.

• In Maryland, officials are embracing geothermal power for schools.

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