HVAC Rated

4-ton central heat pump · 45M Series

Carrier 37MUHAQ60AA3

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

Ranks #131 of 319 4 ton central heat pumps for cooling efficiency, and costs about $1,559 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
54,000 BTU/h98% of its 47°F output
Below average · beats 20%

A good fit if…

  • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 54,000 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 - 33 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
BrandCarrier
Also sold asBryant, WeatherMaker, Midea, Payne
Outdoor unit model37MUHAQ60AA3
Series45M Series
TypeCentral heat pump
Nominal size4 ton
CompressorVariable-speed units run longer at low powerContinuously variable
RefrigerantR-454B
Connected (smart) capableNo
On the market sinceNovember 15, 2018
Last certifiedSeptember 22, 2026
Cooling
SEER2Seasonal efficiency, higher is better17.5 (range 15.2-17.5)
EER2Efficiency at 95°F outdoors10.0-12.0
Cooling capacity47,000-54,000 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better8.1-9.5
Capacity at 47°F55,000-58,000 BTU/h
Capacity at 17°F35,000-45,000 BTU/h
Capacity at 5°F43,000-54,000 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater1.80-1.90
ENERGY STAR cold climateYes
Heating output as it gets colder98% 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 matchups33 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 unitSEER2EER2HSPF2Heat @5°FAHRI ref.
45MUHAQ60XX3 · cold climate17.512.09.554,000215318754
45MUHAQ60XX3 · cold climate17.512.09.554,000215318782
45MUHAQ60XX3 · cold climate17.512.09.554,000215318810
45MUHAQ60XX3 · cold climate17.512.09.554,000215318838
45MUHAQ60XX3 · cold climate17.512.09.554,000215318866
D5FUHAH60XAK · cold climate17.512.09.554,000217557340
D5FUHAH60XAK · cold climate17.512.09.554,000217557349
D5FUHAH60XAK · cold climate17.512.09.554,000217730698
D5FUHAH60XAK · cold climate17.512.09.554,000217730704
D5FUHAH60XAK · cold climate17.512.09.554,000217730710
45MUAAQ60XX3 · cold climate16.010.09.052,000215318753
45MUAAQ60XX3 · cold climate16.010.09.052,000215318781
45MUAAQ60XX3 · cold climate16.010.09.052,000215318809
45MUAAQ60XX3 · cold climate16.010.09.052,000215318837
45MUAAQ60XX3 · cold climate16.010.09.052,000215318865
45MULAQ60XMX · cold climate16.010.08.545,000217456308
45MULAQ60XMX · cold climate16.010.08.545,000217456336
45MULAQ60XMX · cold climate16.010.08.545,000217456364
45MULAQ60XMX · cold climate16.010.08.545,000217456392
45MULAQ60XMX · cold climate16.010.08.545,000217456420
45MULBQ60XMX · cold climate16.010.08.545,000218792386
45MULBQ60XMX · cold climate16.010.08.545,000218792372
45MULBQ60XMX · cold climate16.010.08.545,000218792358
45MULBQ60XMX · cold climate16.010.08.545,000218792344
45MULAQ60XDX · cold climate15.210.08.143,000217456309
45MULAQ60XDX · cold climate15.210.08.143,000217456337
45MULAQ60XDX · cold climate15.210.08.143,000217456365
45MULAQ60XDX · cold climate15.210.08.143,000217456393
45MULAQ60XDX · cold climate15.210.08.143,000217456421
45MULBQ60XDX · cold climate15.210.08.143,000218792387
45MULBQ60XDX · cold climate15.210.08.143,000218792373
45MULBQ60XDX · cold climate15.210.08.143,000218792359
45MULBQ60XDX · cold climate15.210.08.143,000218792345
Yearly running cost in 10 large cities$1,396-$3,725

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 37MUHAQ60AA3?
The Carrier 37MUHAQ60AA3 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 33 certified matchups SEER2 ranges from 15.2-17.5.
Is the Carrier 37MUHAQ60AA3 good for cold climates?
Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 54,000 BTU/h at 5°F with a COP of 1.90, so it is still 1.9 times as efficient as electric resistance heat at that temperature.
How much does the Carrier 37MUHAQ60AA3 cost to run per year?
At its rated efficiency it costs about $1,396-$3,725 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,720 in Phoenix and $3,112 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 37MUHAQ60AA3?
ENERGY STAR lists 33 certified combinations for this outdoor unit. The highest-rated ones use 45MUHAQ60XX3, D5FUHAH60XAK, 45MUAAQ60XX3.
What refrigerant does the Carrier 37MUHAQ60AA3 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 $1,706/yrYou save $1,041/yrSee details ↓
1. Where you live
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.

2. The heat pump Carrier 37MUHAQ60AA3
3. What it replaces
4. Price replace the example with your quote
Heat pump, per year
$1,706
Current system, per year
$2,747
You save per year
$1,041
Payback
18.7 years
Net after 10 years
-$9,095

Cooling $1,046Heating $660Electricity used: 10,663 kWhSaved vs. a minimum-efficiency heat pump: $410

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.

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Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of September 22, 2026. How we use the data.