What is the SEER2 rating of the Carrier 37MUHAQ48AA3?

The Carrier 37MUHAQ48AA3 is rated at up to 17.5 SEER2 and 12.0 EER2 for cooling and up to 9.5 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 20 certified matchups SEER2 ranges from 15.2-17.5.

Is the Carrier 37MUHAQ48AA3 good for cold climates?

Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 48,000 BTU/h at 5°F with a COP of 2.00, so it is still 2.0 times as efficient as electric resistance heat at that temperature.

How much does the Carrier 37MUHAQ48AA3 cost to run per year?

At its rated efficiency it costs about $1,286-$3,240 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,558 in Phoenix and $2,686 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.

Which indoor units work with the Carrier 37MUHAQ48AA3?

ENERGY STAR lists 20 certified combinations for this outdoor unit. The highest-rated ones use 45MUHAQ60XX3, D5FUHAH60XAK, 45MUAAQ48XX3.

4-ton central heat pump · 45M Series

Carrier 37MUHAQ48AA3

Average cooling efficiency and very good heating efficiency for a 4-ton central heat pump, and certified for cold climates.

Ranks #130 of 319 4 ton central heat pumps for cooling efficiency, and costs about $1,375 a year to run in a mixed climate like Atlanta.

SEER2: 17.5 Cooling efficiency over a season
Average · beats 58%
HSPF2: 9.5 Heating efficiency over a season
Very good · beats 70%
EER2: 12.0 Cooling efficiency on a 95°F day
Average · beats 64%
Heat at 5°F: 48,000 BTU/h100% of its 47°F output
Below average · beats 39%

A good fit if…

Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 48,000 BTU/h at 5°F.
It will heat most of the year - its HSPF2 beats 70% of central heat pumps.
You want steady temperatures and quiet running - the compressor varies its speed.
You want a choice of indoor units - 20 certified pairings.

Think twice if…

Nothing stands out - its ratings have no weak spot for its class.

Calculate my running cost

Details

Specifications4 ton, R-454B

General
Brand	Carrier
Also sold as	Bryant, Payne, WeatherMaker, Midea
Outdoor unit model	37MUHAQ48AA3
Series	45M Series
Type	Central heat pump
Nominal size	4 ton
CompressorVariable-speed units run longer at low power	Continuously variable
Refrigerant	R-454B
Connected (smart) capable	No
On the market since	November 15, 2018
Last certified	May 1, 2026
Cooling
SEER2Seasonal efficiency, higher is better	17.5 (range 15.2-17.5)
EER2Efficiency at 95°F outdoors	10.0-12.0
Cooling capacity	45,000-48,000 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better	8.8-9.5
Capacity at 47°F	48,000-50,000 BTU/h
Capacity at 17°F	34,000-39,500 BTU/h
Capacity at 5°F	42,000-48,000 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater	1.85-2.00
ENERGY STAR cold climate	Yes

Heating output as it gets colder100% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with 45MUHAQ60XX3 at the standard test temperatures, in BTU/h:

Certified matchups20 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.
45MUHAQ60XX3 · cold climate	17.5	12.0	9.5	48,000	215318763
45MUHAQ60XX3 · cold climate	17.5	12.0	9.5	48,000	215318791
45MUHAQ60XX3 · cold climate	17.5	12.0	9.5	48,000	215318819
45MUHAQ60XX3 · cold climate	17.5	12.0	9.5	48,000	215318847
45MUHAQ60XX3 · cold climate	17.5	12.0	9.5	48,000	215318875
D5FUHAH60XAK · cold climate	17.5	12.0	9.5	48,000	217557338
D5FUHAH60XAK · cold climate	17.5	12.0	9.5	48,000	217557347
D5FUHAH60XAK · cold climate	17.5	12.0	9.5	48,000	217730703
D5FUHAH60XAK · cold climate	17.5	12.0	9.5	48,000	217730709
D5FUHAH60XAK · cold climate	17.5	12.0	9.5	48,000	217730697
45MUAAQ48XX3 · cold climate	16.5	10.5	9.5	46,000	215318752
45MUAAQ48XX3 · cold climate	16.5	10.5	9.5	46,000	215318780
45MUAAQ48XX3 · cold climate	16.5	10.5	9.5	46,000	215318808
45MUAAQ48XX3 · cold climate	16.5	10.5	9.5	46,000	215318836
45MUAAQ48XX3 · cold climate	16.5	10.5	9.5	46,000	215318864
45MULAQ60XMX · cold climate	15.2	10.0	8.8	42,000	217456306
45MULAQ60XMX · cold climate	15.2	10.0	8.8	42,000	217456334
45MULAQ60XMX · cold climate	15.2	10.0	8.8	42,000	217456362
45MULAQ60XMX · cold climate	15.2	10.0	8.8	42,000	217456390
45MULAQ60XMX · cold climate	15.2	10.0	8.8	42,000	217456418

Yearly running cost in 10 large cities$1,286-$3,240

Phoenix, AZ$1,558/yr
Miami, FL$1,286/yr
Houston, TX$1,395/yr
Atlanta, GA$1,375/yr
Los Angeles, CA$1,330/yr
New York, NY$3,240/yr
Chicago, IL$2,622/yr
Denver, CO$2,173/yr
Seattle, WA$1,330/yr
Minneapolis, MN$2,686/yr

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

Questions5

What is the SEER2 rating of the Carrier 37MUHAQ48AA3?: The Carrier 37MUHAQ48AA3 is rated at up to 17.5 SEER2 and 12.0 EER2 for cooling and up to 9.5 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 20 certified matchups SEER2 ranges from 15.2-17.5.
Is the Carrier 37MUHAQ48AA3 good for cold climates?: Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 48,000 BTU/h at 5°F with a COP of 2.00, so it is still 2.0 times as efficient as electric resistance heat at that temperature.
How much does the Carrier 37MUHAQ48AA3 cost to run per year?: At its rated efficiency it costs about $1,286-$3,240 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,558 in Phoenix and $2,686 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
Which indoor units work with the Carrier 37MUHAQ48AA3?: ENERGY STAR lists 20 certified combinations for this outdoor unit. The highest-rated ones use 45MUHAQ60XX3, D5FUHAH60XAK, 45MUAAQ48XX3.
What refrigerant does the Carrier 37MUHAQ48AA3 use?: It uses R-454B.

Running cost and savings

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

Heat pump $1,531/yrYou save $944/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 Carrier 37MUHAQ48AA3

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: $1,531
Current system, per year: $2,475
You save per year: $944
Payback: 19.1 years
Net after 10 years: -$8,564

Cooling $965Heating $566Electricity used: 9,571 kWhSaved vs. a minimum-efficiency heat pump: $367

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 4 ton models

Blueridge BNG3A60UCN · cold climate17.5 SEER2 · 9.5 HSPF2
Blueridge BNG3A48UCN · cold climate17.5 SEER2 · 9.5 HSPF2
Cooper&Hunter CH-PQ48-230VO · cold climate17.5 SEER2 · 9.5 HSPF2
Blueridge BMSAH60HHC · cold climate17.5 SEER2 · 9.5 HSPF2
Cooper&Hunter CH-PQ55-230VO · cold climate17.5 SEER2 · 9.5 HSPF2
Blueridge BMSAH48HHC · cold climate17.5 SEER2 · 9.5 HSPF2
Day & Night D5CUHAH48AAK · cold climate17.5 SEER2 · 9.5 HSPF2
ApooDr AHU3G-60HFN-B · cold climate17.5 SEER2 · 9.5 HSPF2

See all 319 4 ton central heat pumps, ranked

Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of May 1, 2026. How we use the data.