HeatPumpLab

Geothermal vs. Air-Source Heat Pump Cost Calculator

Compare a ground-source (geothermal) heat pump to an air-source heat pump on annual operating cost, upfront cost, simple payback, and 15-year total cost.

The short answer

Geothermal heat pumps always run cheaper than air-source — typically 25% to 50% less per year — because ground temperatures stay stable while air-source efficiency falls in the cold. But geothermal costs $15,000 to $25,000 more upfront for the ground loop. The 30% federal tax credit (through 2032) closes most of that gap. Geothermal usually wins the 15-year total in cold climates; air-source usually wins in mild ones.

Your home

Compare a ground-source (geothermal) heat pump to an air-source heat pump on operating cost, upfront cost, payback, and 15-year total.

15-year total cost verdict

Air-source wins the 15-year total by about $2,780 in your inputs.

Geothermal always wins on running cost — by $510/yr at these inputs. Whether that overcomes its higher upfront cost over 15 years depends on your climate, electricity rate, and loop type.

Geothermal's upfront premium of $10,500 pays back in about 20.4 years on operating savings alone.

Annual operating cost

Geothermal

$830/yr

4,900 kWh · heat COP 4.0 / cool COP 5.0 (flat)

Air-source

$1,350/yr

7,929 kWh · heat COP 2.4 (Cold) / cool COP 4.2

Upfront installed cost

Air-source

$10,500

No federal credit after 2025

Geothermal (after 30% credit)

$21,000

Gross $30,000 − credit $9,000 · standard loop

Geothermal premium over air-source: $10,500.

15-year total cost (upfront + operating)

Geothermal

$33,500

$21,000 upfront + 15 × $830/yr

Air-source

$30,720

$10,500 upfront + 15 × $1,350/yr

Geothermal ground loops typically last 50+ years; air-source outdoor equipment typically lasts about 15 years. A 15-year total cost understates geothermal's longevity advantage.

Practical caveats

  • Geothermal needs land or boreholes. Horizontal loops need yard area you can excavate; vertical loops need professional drilling. Dense urban lots often can't accommodate either economically.
  • Loop life vs equipment life.Ground loops typically last 50+ years; the indoor heat pump unit lasts 20–25 years. Air-source outdoor units typically last about 15 years. Over 30–50 years geothermal's advantage grows well beyond the 15-year total shown above.
  • Federal tax credit. Geothermal qualifies for a 30% federal credit through 2032 with no cap. Air-source heat pumps no longer qualify for a federal credit after 2025 (the prior 25C credit expired). State and utility incentives may still apply to both — check your local programs.

These are ballpark estimates, not contractor quotes. Geothermal cost varies enormously with loop type, soil conditions, drilling, and site access. The 30% federal credit's eligibility depends on your tax situation — consult a tax professional. Get written quotes from licensed geothermal and HVAC contractors before deciding.

How this calculator works

We estimate annual delivered heating and cooling, divide by each system's seasonal COP to get electricity input, and multiply by your electricity rate. The key difference between systems: geothermal's COP stays flat across climates, while air-source's heating COP drops in the cold.

  • Heat demand (H) = 5.5 kWh/sq ft × home size × heating climate factor (Hot 0.35 to Very Cold 2.30) × insulation factor (Poor 1.30 to Well 0.75).
  • Cooling demand (C) = 2.5 kWh/sq ft × home size × cooling climate factor (Hot 2.50 to Very Cold 0.25) × insulation factor.
  • Geothermal energy use = H ÷ 4.0 + C ÷ 5.0. Geothermal COP stays flat because ground temperatures below the frost line stay near 50–55°F year-round.
  • Air-source energy use = H ÷ air heating COP + C ÷ 4.2. Air-source heating COP varies by climate: Hot 3.2, Warm 3.0, Mixed 2.7, Cold 2.4, Very Cold 2.1. Cooling COP is 4.2 (flat).
  • Upfront cost. Air-source: $4,500 fixed + $3.00/sq ft. Geothermal gross: ($12,000 fixed + $9.00/sq ft) × loop factor (Horizontal 0.85, Standard 1.00, Vertical 1.15). The 30% federal credit (when on) cuts the geothermal upfront by 30%.
  • Simple payback= geothermal's upfront premium ÷ annual operating savings. Shown only when both are positive. Ignores future rate changes and state/utility incentives.
  • 15-year total= upfront + 15 × operating cost for each. Geothermal ground loops last 50+ years; air-source outdoor equipment about 15 years — a longevity advantage that isn't reflected here.

Frequently asked questions

Is a geothermal heat pump worth it?
It depends on your climate and how long you plan to stay in the home. In Cold and Very Cold US climates, geothermal usually wins the 15-year total cost despite its higher upfront — air-source efficiency drops sharply in the cold, while geothermal's COP stays flat. In Hot, Warm, and Mixed climates, air-source typically wins the 15-year total because the operating-cost gap is smaller and can't overcome the geothermal premium. Geothermal ground loops last 50+ years, so if you're staying long-term the math gets better.
How much more does geothermal cost than air-source?
A geothermal heat pump system typically costs $25,000 to $45,000 installed before incentives, vs roughly $10,000 to $16,000 for an air-source system. The ground loop — horizontal trenching or vertical boreholes — is the main extra cost. After the 30% federal tax credit (geothermal qualifies through 2032), geothermal's net upfront is typically $7,000 to $20,000 more than air-source for a typical home.
What is geothermal's payback period?
Simple payback on the upfront premium (after the 30% federal credit) is typically 6 to 10 years in Cold and Very Cold climates with high electricity prices, and 15+ years in Hot, Warm, and Mixed climates. The cooler your climate and the higher your electricity rates, the faster geothermal pays back — because that's where air-source operating cost is highest.
Does geothermal still get the 30% federal tax credit?
Yes — geothermal heat pumps qualify for a 30% federal investment tax credit through 2032, with no cap on system size. The credit applies to equipment and installation, including the ground loop. Air-source heat pumps no longer qualify for a federal credit after 2025 (the prior 25C credit expired). State and utility incentives may still apply to both — check your local programs.
How long do geothermal ground loops last?
Geothermal ground loops typically last 50 years or more — they're inert plastic piping buried below the frost line, with nothing to wear out. The indoor heat pump unit lasts 20 to 25 years, longer than air-source equipment, because it's not exposed to weather. Air-source outdoor units typically last about 15 years. Over 30 to 50 years of ownership, geothermal's longevity advantage is substantial and isn't captured by a 15-year total cost.
Why is geothermal better in cold climates?
Air-source heat pump efficiency falls as outdoor air gets colder — heating COP drops from about 3.2 in Hot climates to about 2.1 in Very Cold climates. Geothermal heat pumps draw heat from the ground at 50–55°F year-round (below the frost line), so their heating COP stays flat at about 4.0 regardless of climate. The colder it gets above ground, the bigger geothermal's efficiency advantage — which is exactly when heating demand is highest.

Disclaimer:These are estimates for budgeting, not contractor quotes. Geothermal installed cost varies enormously with loop type, soil conditions, drilling, and site access. The 30% federal credit's eligibility depends on your tax situation — consult a tax professional. Air-source heat pumps no longer qualify for a federal credit after 2025; state and utility incentives may still apply to both. Get written quotes from licensed geothermal and HVAC contractors before deciding. HeatPumpLab is independently operated and not affiliated with any installer network.