Colorado · NOAA station KDEN
Heating with a mini-split in Denver, CO
The short answer
In Denver, a median ENERGY STAR cold-climate mini-split heating a 24,000 BTU/h design load should cost about $1,116 a year: $460 more than natural gas (90% efficient), and 61% less than electric resistance. The 99% design temperature is 6°F, so capacity at 5°F rarely decides anything here.
The winter you are actually buying for
This is Denver's average year of hourly temperatures from 2015 through 2024 (87,639 readings at Denver International Airport, 100% of all hours). The dashed line is the 99% design temperature: only 1% of hours are colder.
What it costs, by fuel
Mini-split modeled as a median certified cold-climate unit sized to cover the load at 6°F. Seasonal efficiency in Denver's weather: COP 2.55. In 69 hours a year the load exceeds capacity and the estimate adds electric backup.
Three house sizes
| Design load | Heat pump | Gas | Oil | Propane | Resistance | Seasonal COP | Systems that cover it |
|---|---|---|---|---|---|---|---|
| 12,000 BTU/h | $558 | $328 | $736 | $785 | $1,423 | 2.55 | 10,960 of 14,941 |
| 24,000 BTU/h | $1,116 | $656 | $1,473 | $1,570 | $2,846 | 2.55 | 5,425 of 14,941 |
| 36,000 BTU/h | $1,673 | $984 | $2,209 | $2,356 | $4,269 | 2.55 | 2,639 of 14,941 |
The last column counts ENERGY STAR cold-climate systems whose published 5°F and 47°F capacities, joined by a straight line, still reach the design load at Denver's 6°F. How sizing works.
Not a quote. Real bills depend on insulation, thermostat habits, installation and your own Manual J. Use this to decide whether a heat pump is worth pricing, then get two local quotes.
Questions people ask
Will a mini-split work in Denver in winter?
Yes, if it is a cold-climate model. Denver's 99% design temperature from 2015–2024 hourly data is 6°F, and the lowest hour recorded was -22°F. The median ENERGY STAR cold-climate unit keeps 88% of its 47°F heating capacity at 5°F. Hours per year at or below 5°F in Denver: 69.
Is a heat pump cheaper than natural gas in Denver?
At a 24,000 BTU/h design load, we estimate $1,116 a year with a median cold-climate mini-split versus $656 for natural gas at 90% efficiency, using 16.60¢/kWh electricity and 2024 Colorado fuel prices. That is $460 more than natural gas.
How big a mini-split do I need in Denver?
Size to your home's heat loss at 6°F, not to square feet. For a 24,000 BTU/h load, a unit shaped like the median certified system needs about 27,077 BTU/h of 47°F capacity. 5,425 of the 14,941 certified systems cover that load at 6°F.