HVAC Rated

36,000 BTU mini-split heat pump · 45M Series

Carrier 37MBHAQ36AA3

Below average cooling efficiency and very good heating efficiency for a 36,000 BTU mini-split heat pump, and certified for cold climates.

Ranks #98 of 205 36,000 BTU mini-splits for cooling efficiency, and costs about $902 a year to run in a mixed climate like Atlanta.

SEER2
21.3 Cooling efficiency over a season
Below average · beats 35%
HSPF2
11.1 Heating efficiency over a season
Very good · beats 78%
EER2
12.0 Cooling efficiency on a 95°F day
Below average · beats 25%
Heat at 5°F
39,500 BTU/h100% 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 39,500 BTU/h at 5°F.
  • It will heat most of the year - its HSPF2 beats 78% of mini-splits.
  • 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…

  • Cooling cost matters most - its SEER2 is below average for mini-splits.

Calculate my running cost

Details

Specifications36,000 BTU, R-454B
General
BrandCarrier
Also sold asBryant, Payne, WeatherMaker, Midea
Outdoor unit model37MBHAQ36AA3
Series45M Series
TypeMini-split heat pump
Nominal size36,000 BTU
CompressorVariable-speed units run longer at low powerContinuously variable
RefrigerantR-454B
Connected (smart) capableNo
On the market sinceNovember 15, 2018
Last certifiedMarch 13, 2025
Cooling
SEER2Seasonal efficiency, higher is better21.3 (range 17.3-21.3)
EER2Efficiency at 95°F outdoors11.7-12.0
Cooling capacity36,000-36,600 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better9.5-11.1
Capacity at 47°F37,000-42,000 BTU/h
Capacity at 17°F28,000-31,600 BTU/h
Capacity at 5°F37,000-39,500 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater1.95-2.10
ENERGY STAR cold climateYes
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 45MBCAQ36XA3 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 unitSEER2EER2HSPF2Heat @5°FAHRI ref.
45MBCAQ36XA3 CARRIER · cold climate21.312.010.637,000215323842
45MBCAQ36XA3 BRYANT · cold climate21.312.010.637,000215323903
45MBCAQ36XA3 PAYNE · cold climate21.312.010.637,000215323964
45MBCAQ36XA3 Weathermaker · cold climate21.312.010.637,000215324025
45MBCAQ36XA3 MIDEA · cold climate21.312.010.637,000215324086
45MCFAQ36XA3 CARRIER · cold climate20.212.010.839,500215323843
45MCFAQ36XA3 BRYANT · cold climate20.212.010.839,500215323904
45MCFAQ36XA3 PAYNE · cold climate20.212.010.839,500215323965
45MCFAQ36XA3 Weathermaker · cold climate20.212.010.839,500215324026
45MCFAQ36XA3 MIDEA · cold climate20.212.010.839,500215324087
45MBDAQ36XH3 CARRIER · cold climate17.812.011.137,600215323844
45MBDAQ36XH3 BRYANT · cold climate17.812.011.137,600215323905
45MBDAQ36XH3 PAYNE · cold climate17.812.011.137,600215323966
45MBDAQ36XH3 Weathermaker · cold climate17.812.011.137,600215324027
45MBDAQ36XH3 MIDEA · cold climate17.812.011.137,600215324088
45MBAAQ36XA3 · cold climate17.311.79.538,000215318825
45MBAAQ36XA3 · cold climate17.311.79.538,000215318881
45MBAAQ36XA3 · cold climate17.311.79.538,000215318769
45MBAAQ36XA3 · cold climate17.311.79.538,000215318797
45MBAAQ36XA3 · cold climate17.311.79.538,000215318853
Yearly running cost in 10 large cities$803-$2,160

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 37MBHAQ36AA3?
The Carrier 37MBHAQ36AA3 is rated at up to 21.3 SEER2 and 12.0 EER2 for cooling and up to 11.1 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 20 certified matchups SEER2 ranges from 17.3-21.3.
Is the Carrier 37MBHAQ36AA3 good for cold climates?
Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 39,500 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 Carrier 37MBHAQ36AA3 cost to run per year?
At its rated efficiency it costs about $803-$2,160 a year in electricity in large U.S. cities, depending on climate and local rates - for example $992 in Phoenix and $1,805 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 37MBHAQ36AA3?
ENERGY STAR lists 20 certified combinations for this outdoor unit. The highest-rated ones use CARRIER 45MBCAQ36XA3, BRYANT 45MBCAQ36XA3, PAYNE 45MBCAQ36XA3.
What refrigerant does the Carrier 37MBHAQ36AA3 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 $985/yrYou save $918/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 37MBHAQ36AA3
3. What it replaces
4. Price replace the example with your quote
Heat pump, per year
$985
Current system, per year
$1,903
You save per year
$918
Payback
14.7 years
Net after 10 years
-$4,319

Cooling $602Heating $383Electricity used: 6,156 kWhSaved vs. a minimum-efficiency heat pump: $479

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 36,000 BTU models

See all 205 36,000 BTU mini-splits, ranked

Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of March 13, 2025. How we use the data.