What is the SEER2 rating of the Gibson GXH24(7.0)FMK4DH-1?

The Gibson GXH24(7.0)FMK4DH-1 is rated at up to 21.0 SEER2 and 12.5 EER2 for cooling and up to 10.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.

Is the Gibson GXH24(7.0)FMK4DH-1 good for cold climates?

Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 21,600 BTU/h at 5°F with a COP of 2.10, so it is still 2.1 times as efficient as electric resistance heat at that temperature.

How much does the Gibson GXH24(7.0)FMK4DH-1 cost to run per year?

At its rated efficiency it costs about $521-$1,491 a year in electricity in large U.S. cities, depending on climate and local rates - for example $656 in Phoenix and $1,257 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.

What refrigerant does the Gibson GXH24(7.0)FMK4DH-1 use?

It uses R-410A. R-410A is being phased down under the EPA AIM Act, and new systems are moving to R-454B and R-32.

24,000 BTU mini-split heat pump · Flex Match

Gibson GXH24(7.0)FMK4DH-1

Below average cooling efficiency and average heating efficiency for a 24,000 BTU mini-split heat pump, and certified for cold climates.

Ranks #286 of 430 24,000 BTU mini-splits for cooling efficiency, and costs about $614 a year to run in a mixed climate like Atlanta.

SEER2: 21.0 Cooling efficiency over a season
Below average · beats 30%
HSPF2: 10.0 Heating efficiency over a season
Average · beats 43%
EER2: 12.5 Cooling efficiency on a 95°F day
Average · beats 44%
Heat at 5°F: 21,600 BTU/h90% of its 47°F output
Average · beats 67%

A good fit if…

Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 21,600 BTU/h at 5°F.
You want steady temperatures and quiet running - the compressor varies its speed.

Think twice if…

Cooling cost matters most - its SEER2 is below average for mini-splits.
You want the newest refrigerant - it uses R-410A, which is being phased down.

Calculate my running cost

Details

Specifications24,000 BTU, R-410A

General
Brand	Gibson
Also sold as	Airtemp, AireForce
Outdoor unit model	GXH24(7.0)FMK4DH-1
Series	Flex Match
Type	Mini-split heat pump
Nominal size	24,000 BTU
CompressorVariable-speed units run longer at low power	Continuously variable
Refrigerant	R-410A
Connected (smart) capable	No
On the market since	May 11, 2023
Last certified	June 13, 2026
Cooling
SEER2Seasonal efficiency, higher is better	21.0 (range 21.0)
EER2Efficiency at 95°F outdoors	12.5
Cooling capacity	23,200 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better	10.0
Capacity at 47°F	24,000 BTU/h
Capacity at 17°F	23,600 BTU/h
Capacity at 5°F	21,600 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater	2.10
ENERGY STAR cold climate	Yes

Heating output as it gets colder90% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its best matchup at the standard test temperatures, in BTU/h:

Certified matchups3 indoor units

The same outdoor unit scores differently with each indoor unit. Ask your installer for the AHRI reference number of the exact system you are quoted.

Indoor unit	SEER2	EER2	HSPF2	Heat @5°F	AHRI ref.
- GIBSON · cold climate	21.0	12.5	10.0	21,600	210276801
- AIRTEMP · cold climate	21.0	12.5	10.0	21,600	210276806
- AireForce · cold climate	21.0	12.5	10.0	21,600	211635193

Yearly running cost in 10 large cities$521-$1,491

Phoenix, AZ$656/yr
Miami, FL$521/yr
Houston, TX$588/yr
Atlanta, GA$614/yr
Los Angeles, CA$602/yr
New York, NY$1,491/yr
Chicago, IL$1,215/yr
Denver, CO$1,014/yr
Seattle, WA$626/yr
Minneapolis, MN$1,257/yr

At each state's average electricity price and the city's typical heating and cooling hours.

Questions4

What is the SEER2 rating of the Gibson GXH24(7.0)FMK4DH-1?: The Gibson GXH24(7.0)FMK4DH-1 is rated at up to 21.0 SEER2 and 12.5 EER2 for cooling and up to 10.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
Is the Gibson GXH24(7.0)FMK4DH-1 good for cold climates?: Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 21,600 BTU/h at 5°F with a COP of 2.10, so it is still 2.1 times as efficient as electric resistance heat at that temperature.
How much does the Gibson GXH24(7.0)FMK4DH-1 cost to run per year?: At its rated efficiency it costs about $521-$1,491 a year in electricity in large U.S. cities, depending on climate and local rates - for example $656 in Phoenix and $1,257 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
What refrigerant does the Gibson GXH24(7.0)FMK4DH-1 use?: It uses R-410A. R-410A is being phased down under the EPA AIM Act, and new systems are moving to R-454B and R-32.

Running cost and savings

Pre-filled with this model. Pick your city and what you heat with today; everything else is optional.

Heat pump $658/yrYou save $552/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 Gibson GXH24(7.0)FMK4DH-1

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: $658
Current system, per year: $1,209
You save per year: $552
Payback: 15.4 years
Net after 10 years: -$2,983

Cooling $389Heating $269Electricity used: 4,110 kWhSaved vs. a minimum-efficiency heat pump: $272

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.

Similar 24,000 BTU models

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ECO AC EMH-3O24KBB · cold climate21.0 SEER2 · 10.0 HSPF2
LG KUSXB301A · cold climate21.0 SEER2 · 10.0 HSPF2
Deye DWB3-ACDC-24KR2(US) · cold climate21.0 SEER2 · 10.0 HSPF2
TOSOT TM24D6MO · cold climate21.0 SEER2 · 10.0 HSPF2
Daikin 3MXM24AVJU8 · cold climate21.0 SEER2 · 10.0 HSPF2
Trane 4TXM2124A13N0 · cold climate21.0 SEER2 · 10.0 HSPF2

See all 430 24,000 BTU mini-splits, ranked

Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of June 13, 2026. How we use the data.