Do heat pumps work in Charleston winters?

Winters in Charleston are mild, so heating efficiency matters less than cooling. The average winter low is 46°F, and the heating season adds up to 1,623 heating degree days (NOAA 1991-2020 normals).

How much does it cost to run a heat pump in Charleston?

A typical 3-ton central heat pump (17.0 SEER2, 9.0 HSPF2) uses about $409 of electricity a year for heating and $566 for cooling in Charleston, at the South Carolina average of 15.7¢/kWh. The most efficient models cost less - see the rankings above.

Is a heat pump cheaper than a gas furnace in Charleston?

Not on heating alone at today's prices: about $409 a year with a typical heat pump versus $401 with a 95% gas furnace (South Carolina averages: 15.7¢/kWh, $1.63/therm). A high-HSPF2 model narrows the gap, and a heat pump also replaces the air conditioner. Against propane, oil or electric heat it is usually far cheaper.

What size heat pump do I need for a 2,000 sq ft house in Charleston?

With average insulation, roughly a 3-ton system: the estimated cooling load is 32,100 BTU/h and the heating load 30,000 BTU/h. Use the size calculator for your own house, and ask installers for a Manual J calculation.

Mild winters · Hot summers

Best heat pumps for Charleston, SC

Winters in Charleston are mild, so heating efficiency matters less than cooling.

A typical heat pump costs about $409 a year to heat a house here and $566 to cool it. A 95% gas furnace would cost $401 for the same heat.

Nights at or below 0°F0 a year
Nights at or below 20°F0.1 a year
Days at or above 90°F25 a year
Average winter low46°F
Average summer high86°F
Electricity15.7¢ per kWh
Natural gas$1.63 per therm

Cheapest to run in Charleston

Ranked by yearly electricity cost in this climate, so the balance of heating and cooling efficiency is the one that matters here.

Best 12,000 BTU mini-split

Fujitsu AOUH12KTAP1

12,000 BTU mini-split · AIRSTAGE H-Series · cold-climate certified

SEER2: 31.5
HSPF2: 13.7
Per year here: $191

For one large room.

Full specs and running cost

Best 24,000 BTU mini-split

SLIMAIR SHC24VH2AG

24,000 BTU mini-split · SHC Series · cold-climate certified

SEER2: 27.5
HSPF2: 14.5
Per year here: $402

For open-plan floor or small home.

Full specs and running cost

Best 3-ton central heat pump

TOSHIBA CARRIER MCY-MUB0368HS2P-UL

3 ton central · cold-climate certified

SEER2: 29.7
HSPF2: 12.2
Per year here: $625

For typical whole house.

Full specs and running cost

Running cost calculator for Charleston

Pre-filled with Charleston's climate and South Carolina prices. Pick a model, tell it what you heat with today, and add your quote.

Heat pump $593/yrYou save $366/yrSee details ↓

1. Where you live

StateCityElectricity ¢ per kWh

Adjust heating and cooling hours

Filled in from your city's climate. Change them if you run the system much more or less than usual.

Cooling hours full-load hours per yearHeating hours full-load hours per year

2. The heat pump pick a model or type its ratings

Find a model (fills in the ratings below)

SEER2 cooling efficiencyHSPF2 heating efficiencyCooling capacity BTU/hHeating capacity BTU/h

3. What it replaces

Current heatingFurnace efficiency (AFUE %)Gas price, $/thermCurrent coolingOld AC rating SEER2 (10 ≈ 15+ years old)

4. Price replace the example with your quote

Installed price, $Rebates and incentives, $ utility, state

Heat pump, per year: $593
Current system, per year: $959
You save per year: $366
Payback: 24.6 years
Net after 10 years: -$5,339

Cooling $321Heating $272Electricity used: 3,773 kWhSaved vs. a minimum-efficiency heat pump: $182

Estimates use the unit's rated SEER2 and HSPF2, full-load hours derived from NOAA 1991-2020 degree days, average residential electricity prices from the U.S. EIA (12 months to July 2026) and fuel prices from EIA (2025 for natural gas, week of 2026-10-05 for propane and heating oil). Very cold days that need backup heat are not modelled. Federal minimum for comparison: 14.3 SEER2 / 7.5 HSPF2.

More for Charleston

Top 5 12,000 BTU mini-splitsfrom $191/yr

Model	SEER2	HSPF2	Per year
Fujitsu AOUH12KTAP1	31.5	13.7	$191
MDV MOX430-12HFN1-MZ60W	27.5	14.5	$201
Goodman MSH123G26MCAA	27.5	14.5	$201
Fujitsu AOUH12KZAH1	30.5	12.7	$202
Fujitsu AOUG12LZAS1	29.4	12.9	$204

All 12,000 BTU mini-splits

Top 5 24,000 BTU mini-splitsfrom $402/yr

Model	SEER2	HSPF2	Per year
SLIMAIR SHC24VH2AG	27.5	14.5	$402
Quilt QO1-M3Z27-NC-NA	25.3	12.0	$458
MDV MOD30-24HFN10-M1X	22.3	13.5	$469
Mainline ML24HP230NEXH-O	22.3	13.3	$472
ComfortStar CHF3-24CD(O)	22.3	13.3	$472

All 24,000 BTU mini-splits

Top 5 3-ton central heat pumpsfrom $625/yr

Model	SEER2	HSPF2	Per year
TOSHIBA CARRIER MCY-MUB0368HS2P-UL	29.7	12.2	$625
LG KUSXA361A	23.5	10.5	$760
LG KUSXB361A	22.0	10.3	$794
Trane 5TWV0X36A1	21.0	10.5	$808
Heil H5H3V36KAAA	22.5	9.5	$815

All 3-ton central heat pumps

Heat pump vs. gas, propane and oilgas is cheaper to run

Yearly cost to heat a typical house (36,000 BTU/h of heat, 650 full-load hours) at South Carolina prices.

Natural gas furnace, 95% AFUE$401/yr
Heat pump (typical, 9.0 HSPF2)$409/yr
Natural gas furnace, 80% AFUE$477/yr
Propane furnace, 95% AFUE$720/yr
Electric baseboard or furnace$1,078/yr
Heating oil, 85% AFUE$1,187/yr

Electricity and natural gas: South Carolina residential averages from the U.S. EIA; propane and heating oil: latest EIA weekly prices.

Month by monthpeak $124 in July

Heating and cooling degree days (NOAA 1991-2020 normals) and what a typical 3-ton heat pump costs in each month at 15.7¢/kWh.

Month	Heating DD	Cooling DD	Cost
January	442	2	$112
February	334	3	$85
March	213	21	$59
April	62	92	$37
May	6	269	$64
June	0	428	$99
July	0	536	$124
August	0	510	$118
September	1	377	$87
October	33	169	$47
November	181	34	$53
December	353	7	$90

What size heat pump for a Charleston home?3 ton for 2,000 sq ft

1,000 sq ft house2 ton · heating load 15,000 BTU/h
1,500 sq ft house2.5 ton · heating load 22,500 BTU/h
2,000 sq ft house3 ton · heating load 30,000 BTU/h
2,500 sq ft house3 ton · heating load 37,500 BTU/h

Average insulation, 8 ft ceilings. Size calculator for your own home

Questions4

Do heat pumps work in Charleston winters?: Winters in Charleston are mild, so heating efficiency matters less than cooling. The average winter low is 46°F, and the heating season adds up to 1,623 heating degree days (NOAA 1991-2020 normals).
How much does it cost to run a heat pump in Charleston?: A typical 3-ton central heat pump (17.0 SEER2, 9.0 HSPF2) uses about $409 of electricity a year for heating and $566 for cooling in Charleston, at the South Carolina average of 15.7¢/kWh. The most efficient models cost less - see the rankings above.
Is a heat pump cheaper than a gas furnace in Charleston?: Not on heating alone at today's prices: about $409 a year with a typical heat pump versus $401 with a 95% gas furnace (South Carolina averages: 15.7¢/kWh, $1.63/therm). A high-HSPF2 model narrows the gap, and a heat pump also replaces the air conditioner. Against propane, oil or electric heat it is usually far cheaper.
What size heat pump do I need for a 2,000 sq ft house in Charleston?: With average insulation, roughly a 3-ton system: the estimated cooling load is 32,100 BTU/h and the heating load 30,000 BTU/h. Use the size calculator for your own house, and ask installers for a Manual J calculation.

Nearby cities

Climate: NOAA 1991-2020 normals, station CHARLESTON CITY (7 km away).