HVAC Rated
    Menu

      42,000 BTU mini-split heat pump · M5O series

      MDV M5OG-42HFN1-M-[X]

      Average cooling and heating efficiency for a 42,000 BTU mini-split heat pump, and certified for cold climates.

      Ranks #12 of 61 42,000 BTU mini-splits for cooling efficiency, and costs about $1,057 a year to run in a mixed climate like Atlanta.

      SEER2
      22.3 Cooling efficiency over a season
      Average · beats 53%
      HSPF2
      10.5 Heating efficiency over a season
      Average · beats 61%
      EER2
      11.7 Cooling efficiency on a 95°F day
      Below average · beats 16%
      Heat at 5°F
      44,000 BTU/h102% of its 47°F output
      Average · beats 48%

      A good fit if…

      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 44,000 BTU/h at 5°F.
      • You want steady temperatures and quiet running - the compressor varies its speed.

      Think twice if…

      • You want the newest refrigerant - it uses R-410A, which is being phased down.

      Calculate my running cost

      Details

      Specifications42,000 BTU, R-410A
      General
      BrandMDV
      Outdoor unit modelM5OG-42HFN1-M-[X]
      SeriesM5O series
      TypeMini-split heat pump
      Nominal size42,000 BTU
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-410A
      Connected (smart) capableNo
      On the market sinceApril 18, 2023
      Last certifiedJune 13, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better22.3 (range 18.7-22.3)
      EER2Efficiency at 95°F outdoors11.7
      Cooling capacity42,000-43,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better9.6-10.5
      Capacity at 47°F43,000 BTU/h
      Capacity at 17°F45,000 BTU/h
      Capacity at 5°F42,500-44,000 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater2.00
      ENERGY STAR cold climateYes
      Heating output as it gets colder102% 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 matchups2 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.
      - · cold climate22.311.710.544,000207617657
      - · cold climate18.711.79.642,500207617659
      Yearly running cost in 10 large cities$908-$2,555

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

      Questions4
      What is the SEER2 rating of the MDV M5OG-42HFN1-M-[X]?
      The MDV M5OG-42HFN1-M-[X] is rated at up to 22.3 SEER2 and 11.7 EER2 for cooling and up to 10.5 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 2 certified matchups SEER2 ranges from 18.7-22.3.
      Is the MDV M5OG-42HFN1-M-[X] good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 44,000 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 MDV M5OG-42HFN1-M-[X] cost to run per year?
      At its rated efficiency it costs about $908-$2,555 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,137 in Phoenix and $2,149 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
      What refrigerant does the MDV M5OG-42HFN1-M-[X] 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 $1,137/yrYou save $1,080/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 MDV M5OG-42HFN1-M-[X]
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $1,137
      Current system, per year
      $2,217
      You save per year
      $1,080
      Payback
      14.8 years
      Net after 10 years
      -$5,202

      Cooling $679Heating $459Electricity used: 7,109 kWhSaved vs. a minimum-efficiency heat pump: $563

      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 42,000 BTU models

      See all 61 42,000 BTU mini-splits, ranked

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