Do heat pumps work in Gaithersburg winters?

Gaithersburg sees about 25 nights a year at or below 20°F. A cold-climate certified model keeps the house warm without leaning on backup heat. The average winter low is 27°F, and the heating season adds up to 4,604 heating degree days (NOAA 1991-2020 normals).

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

A typical 3-ton central heat pump (17.0 SEER2, 9.0 HSPF2) uses about $1,651 of electricity a year for heating and $402 for cooling in Gaithersburg, at the Maryland average of 22.3¢/kWh. The most efficient models cost less - see the rankings above.

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

Not on heating alone at today's prices: about $1,651 a year with a typical heat pump versus $1,094 with a 95% gas furnace (Maryland averages: 22.3¢/kWh, $1.56/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 Gaithersburg?

With average insulation, roughly a 4-ton system: the estimated cooling load is 30,600 BTU/h and the heating load 46,000 BTU/h. Use the size calculator for your own house, and ask installers for a Manual J calculation.

Cold winters · Warm summers

Best heat pumps for Gaithersburg, MD

Gaithersburg sees about 25 nights a year at or below 20°F. A cold-climate certified model keeps the house warm without leaning on backup heat.

A typical heat pump costs about $1,651 a year to heat a house here and $402 to cool it. A 95% gas furnace would cost $1,094 for the same heat.

Nights at or below 0°F0.5 a year
Nights at or below 20°F25 a year
Days at or above 90°F33 a year
Average winter low27°F
Average summer high86°F
Electricity22.3¢ per kWh
Natural gas$1.56 per therm

Cheapest to run in Gaithersburg

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

Best 12,000 BTU mini-split

MDV MOX430-12HFN1-MZ60W

12,000 BTU mini-split · MSOP series · cold-climate certified

SEER2: 27.5
HSPF2: 14.5
Per year here: $424

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: $849

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: $1,448

For typical whole house.

Full specs and running cost

Running cost calculator for Gaithersburg

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

Heat pump $1,328/yrCosts more by $7/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: $1,328
Current system, per year: $1,321
Costs more per year: $7
Payback: No payback
Net after 10 years: -$9,073

Cooling $228Heating $1,101Electricity used: 5,953 kWhSaved vs. a minimum-efficiency heat pump: $311

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 Gaithersburg

Top 5 12,000 BTU mini-splitsfrom $424/yr

Model	SEER2	HSPF2	Per year
MDV MOX430-12HFN1-MZ60W	27.5	14.5	$424
Goodman MSH123G26MCAA	27.5	14.5	$424
Fujitsu AOUH12KTAP1	31.5	13.7	$434
Fujitsu AOUG12LZAS1	29.4	12.9	$461
Fujitsu AOUH12KZAH1	30.5	12.7	$465

All 12,000 BTU mini-splits

Top 5 24,000 BTU mini-splitsfrom $849/yr

Model	SEER2	HSPF2	Per year
SLIMAIR SHC24VH2AG	27.5	14.5	$849
MDV MOD30-24HFN10-M1X	22.3	13.5	$938
Arcoaire D5CSHAH24AAK	21.2	13.5	$948
Mainline ML24HP230NEXH-O	22.3	13.3	$949
ComfortStar CHF3-24CD(O)	22.3	13.3	$949

All 24,000 BTU mini-splits

Top 5 3-ton central heat pumpsfrom $1,448/yr

Model	SEER2	HSPF2	Per year
TOSHIBA CARRIER MCY-MUB0368HS2P-UL	29.7	12.2	$1,448
LG KUSXA361A	23.5	10.5	$1,706
Trane 5TWV0X36A1	21.0	10.5	$1,740
Lennox SL22KLV-036-230A	20.5	10.5	$1,748
LG KUSXB361A	22.0	10.3	$1,753

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, 1,850 full-load hours) at Maryland prices.

Natural gas furnace, 95% AFUE$1,094/yr
Natural gas furnace, 80% AFUE$1,299/yr
Heat pump (typical, 9.0 HSPF2)$1,651/yr
Propane furnace, 95% AFUE$2,915/yr
Heating oil, 85% AFUE$3,457/yr
Electric baseboard or furnace$4,355/yr

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

Month by monthpeak $346 in January

Heating and cooling degree days (NOAA 1991-2020 normals) and what a typical 3-ton heat pump costs in each month at 22.3¢/kWh.

Month	Heating DD	Cooling DD	Cost
January	964	0	$346
February	801	0	$287
March	647	2	$233
April	320	20	$121
May	115	84	$69
June	13	238	$82
July	0	378	$123
August	1	334	$109
September	45	153	$66
October	284	22	$109
November	570	1	$205
December	845	0	$303

What size heat pump for a Gaithersburg home?4 ton for 2,000 sq ft

1,000 sq ft house2 ton · heating load 23,000 BTU/h
1,500 sq ft house3 ton · heating load 34,500 BTU/h
2,000 sq ft house4 ton · heating load 46,000 BTU/h
2,500 sq ft house5 ton · heating load 57,500 BTU/h

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

Questions4

Do heat pumps work in Gaithersburg winters?: Gaithersburg sees about 25 nights a year at or below 20°F. A cold-climate certified model keeps the house warm without leaning on backup heat. The average winter low is 27°F, and the heating season adds up to 4,604 heating degree days (NOAA 1991-2020 normals).
How much does it cost to run a heat pump in Gaithersburg?: A typical 3-ton central heat pump (17.0 SEER2, 9.0 HSPF2) uses about $1,651 of electricity a year for heating and $402 for cooling in Gaithersburg, at the Maryland average of 22.3¢/kWh. The most efficient models cost less - see the rankings above.
Is a heat pump cheaper than a gas furnace in Gaithersburg?: Not on heating alone at today's prices: about $1,651 a year with a typical heat pump versus $1,094 with a 95% gas furnace (Maryland averages: 22.3¢/kWh, $1.56/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 Gaithersburg?: With average insulation, roughly a 4-ton system: the estimated cooling load is 30,600 BTU/h and the heating load 46,000 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 WASHINGTON DC DULLES AP (32 km away).