Both geothermal and air-source heat pumps heat and cool your home using electricity — no combustion, no gas bill. But they work very differently, cost different amounts, and perform differently in Oklahoma’s climate. Here’s what you need to know before choosing.
How Each System Works
Air-Source Heat Pump
Moves heat between your home and the outdoor air. In winter, it extracts heat from outside air (even cold air contains heat energy) and moves it inside. In summer, it reverses — extracting heat from inside and dumping it outdoors. Efficiency drops when outdoor temps fall below 20°F, requiring electric resistance backup heat.
Moves heat between your home and the ground (or groundwater). Below 6 feet, Oklahoma soil stays between 58–62°F year-round. Geothermal uses this stable temperature as its heat source in winter and heat sink in summer — regardless of whether it’s 105°F or 5°F outside.
Efficiency Comparison
In Oklahoma, geothermal heat pumps outperform air-source on efficiency (COP 3.5–5 vs 2–3), winter reliability, and operating cost — but cost $15,000–$30,000 installed vs $5,000–$12,000 for air-source. With CKenergy or OG&E rebates, geothermal payback runs 5–9 years. For Oklahoma’s 100°F summers and occasional ice storms, geothermal wins long-term if the budget allows. Air-source is the right call when budget is the constraint.
| Air-Source Heat Pump | Geothermal Heat Pump | |
|---|---|---|
| Heating COP | 2.0–3.5 (drops in cold) | 3.5–5.3 (stable year-round) |
| Cooling EER | 14–20 SEER2 | Up to 45 EER (ClimateMaster Q45) |
| Performance at 5°F | Reduced — backup heat activates | Full rated efficiency |
| Performance at 105°F | Reduced — hot outdoor air increases work | Full rated efficiency |
Installation Cost in Oklahoma
Air-source heat pump: $4,000–$10,000 installed for a standard split system. Ductless mini-split variants run $2,500–$5,000 per zone.
Geothermal: $18,000–$40,000 installed, depending on home size and loop configuration. Higher upfront cost is partially offset by Oklahoma utility rebates and lower operating costs over time.
Oklahoma Rebates: A Significant Difference
Oklahoma utilities offer meaningful rebates on geothermal that don’t apply to air-source systems:
- CKenergy Electric Cooperative: $2,000 per ton — a 3-ton system earns $6,000 back. Maximum $24,000.
- OG&E: $1,000 per ton geothermal; up to $1,500 for air-source heat pumps (max $3,000)
- Cimarron Electric: $600 for geothermal (new or replacement)
- CVEC, OEC, KPWA, Central Electric: Geothermal rebates vary — call your utility to confirm current amounts
The federal Section 25D geothermal tax credit expired December 31, 2025. Oklahoma utility rebates remain fully active and are the primary savings mechanism for 2026 geothermal installs. See the Oklahoma geothermal rebates guide for current amounts.
Which Is Right for Your Property?
Geothermal makes the most sense when:
- You have adequate land for a horizontal loop field (at least half an acre) or can drill vertically
- You’re in a CKenergy service territory — the rebate alone can change the math dramatically
- You plan to stay in the home 10+ years
- You want the lowest possible operating cost and no gas utility connection
Air-source makes more sense when:
- Your lot is small or drilling isn’t feasible
- Budget is the primary constraint
- You need a faster installation (air-source can typically be done in one day)
- You’re adding a single zone (ductless mini-split is hard to beat for additions and garages)
Not Sure Which System Is Right for You?
Hartzell’s installs both — we’ll give you an honest recommendation based on your property and utility provider.
Need service? See our Geothermal Overview page for pricing, service area, and same-day availability across central Oklahoma. Call 405-375-4822.
Also Serving
Kingfisher
Enid
Yukon
Mustang
Edmond
Guthrie
El Reno
Weatherford
Questions? Ready to Schedule?
Call 405-375-4822 or book online. Same-day appointments often available. Free estimates on new systems.
Related Services from Hartzell’s Heat & Air
- Geothermal Heat Pumps — full overview of geothermal systems for Oklahoma homes
- Geothermal Installation Oklahoma — our installation process and what to expect
- Oklahoma Geothermal Rebates 2026 — utility rebates that can offset the higher upfront cost
Frequently Asked Questions
Is geothermal worth it in Oklahoma?
For most properties in CKenergy territory, yes — the $2,000/ton rebate combined with 40–60% lower operating costs makes geothermal financially competitive over a 10-year horizon. Outside CKenergy territory, payback is longer but operating savings are still substantial.
Can a heat pump handle Oklahoma winters?
Modern air-source heat pumps with variable-speed compressors can operate down to -13°F, though efficiency drops below 20°F. Geothermal heat pumps maintain full efficiency regardless of outdoor temperature since they exchange heat with the ground, not the air.
What is the CKenergy geothermal rebate?
CKenergy Electric Cooperative offers $2,000 per ton of geothermal capacity, up to a maximum of $24,000. A standard 3-ton system earns $6,000 back. Hartzell’s handles the rebate paperwork as part of the installation.
Content reviewed by Dave Hartzell — Oklahoma Master HVAC License #00115936, IGSHPA Accredited Geothermal Installer, Mitsubishi Diamond Dealer, Trane Comfort Specialist TCS SELECT. Hartzell’s Heat & Air, Kingfisher OK, for 15+ years.