Guides / Pools · Updated
Pool heat pump sizes
From each maker's own spec sheet and installation manual, read November 2026. Ratings are AHRI 1160, the test every maker uses.
Short answer
Residential pool heat pumps run from 85k to 145k Btu/h at 80°F air, and lose 32 to 46% of that at 50°F. Under California's sizing rule the biggest here, the Pentair UltraTemp 140, heats a pool up to 28,361 gallons. Their manuals call for a 230 V circuit rated 38 to 46 amps.
By maker
Btu/h is the heat it puts into the water. COP is heat out for each unit of electricity in: at 5.7, a kilowatt-hour of electricity puts 5.7 kWh of heat in the pool. “Biggest pool” is the largest it can warm 10°F in 17.5 hours at 80°F air and 63% humidity, California's rule.
| Model | Btu/h, 80°F air | Btu/h, 50°F air | COP 80° / 50° | Biggest pool | Circuit (MCA / max breaker) |
|---|---|---|---|---|---|
| UltraTemp 110 | 110,000 | 70,000 | 6.1 / 4 | 21,218 gal | 42 A / 70 A |
| UltraTemp 120Q | 127,000 | 80,000 | 5.7 / 4 | 25,210 gal | – |
| UltraTemp 140 | 145,000 | 90,000 | 5.8 / 4 | 28,361 gal | 43 A / 70 A |
| UltraTemp 120 H/C (heats and cools) | 125,000 | 80,000 | 5.5 / 4 | 24,790 gal | 42 A / 70 A |
| UltraTemp 140 H/C (heats and cools) | 140,000 | 85,000 | 5.6 / 4 | 27,731 gal | 43 A / 70 A |
| Model | Btu/h, 80°F air | Btu/h, 50°F air | COP 80° / 50° | Biggest pool | Circuit (MCA / max breaker) |
|---|---|---|---|---|---|
| HeatPro HP21105T | 110,000 | 75,000 | 5.7 / 4 | 21,008 gal | 38.9 A / 65 A |
| HeatPro HP21205T | 120,000 | 75,000 | 5.7 / 4 | 23,109 gal | 38.9 A / 65 A |
| HeatPro HP21405T | 138,000 | 82,000 | 5.7 / 4 | 26,891 gal | 42.5 A / 70 A |
| HeatPro HP31105T (heats and cools) | 110,000 | 75,000 | 5.7 / 4 | 21,008 gal | 38.9 A / 65 A |
| HeatPro HP31205T (heats and cools) | 120,000 | 75,000 | 5.7 / 4 | 23,109 gal | 38.9 A / 65 A |
| HeatPro HP31405T (heats and cools) | 135,000 | 82,000 | 5.7 / 4 | 26,261 gal | 42.5 A / 70 A |
| HeatPro VS HP51202T (heats and cools) | 120,000 | 65,000 | 5.8 / 4 | – | 45 A / 60 A |
| Model | Btu/h, 80°F air | Btu/h, 50°F air | COP 80° / 50° | Biggest pool | Circuit (MCA / max breaker) |
|---|---|---|---|---|---|
| Crosswind V 4550 | 85,000 | 56,000 | 5.8 / 4 | 16,807 gal | 38 A / 60 A |
| Crosswind V 5550 | 102,000 | 65,000 | 6.1 / 4.1 | 19,958 gal | 40 A / 70 A |
| Crosswind V 6550 | 118,000 | 75,000 | 6.1 / 4.1 | 23,109 gal | 46 A / 70 A |
| Crosswind V 8550 | 138,000 | 87,000 | 6 / 4.2 | 27,311 gal | 46 A / 70 A |
| Crosswind V 6550 heat/cool (heats and cools) | 115,000 | 72,000 | 6 / 4 | 22,689 gal | 46 A / – |
| Crosswind V 8550 heat/cool (heats and cools) | 137,000 | 85,000 | 5.8 / 4.1 | 27,101 gal | 46 A / – |
– means the maker's documents don't give it. MCA is the minimum circuit ampacity; the max breaker is the largest breaker or fuse the manual allows (Pentair's “max fuse breaker size”, Hayward's “MOP”, Raypak's maximum breaker). The electrician sizes the wire and breaker to the nameplate.
Size for the coldest air you swim in
A heat pump pulls heat from the air, so it makes less as the air cools. Every model above puts out 32 to 46% less at 50°F than at 80°F. If you want to swim in spring and fall, pick on the 50°F column, or put in your pool in the pool heater size calculator and choose 50°F air.
How the biggest-pool number works
gallons = Btu/h at 80°F air, 63% humidity × 17.5 hours ÷ (8.33 × 10°F)
A gallon of water weighs 8.33 lb and takes 1 Btu per pound to warm 1°F. California's energy code (Reference Appendix JA16.3) wants a pool heat pump to add 10°F in no more than 17.5 hours. Raypak publishes the same limit per model: 27,311 gallons for the Crosswind V 8550, which is what the formula gives.
Not here
Jandy: its website blocks automated reads of its spec sheets, so we couldn't check its numbers. AquaCal: its current site can't be read, and the documents we found may not be the models on sale now. Hayward's two “140,000 Btu” MCHX models are rated 138,000 and 135,000 in its own brochure, so those are the figures used.