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      3-ton central heat pump · FRIGIDAIRE FSH4BF SERIES

      Frigidaire FSH4BF5M2SX36K

      Below average cooling and heating efficiency for a 3-ton central heat pump, but not rated for cold climates.

      Ranks #245 of 302 3 ton central heat pumps for cooling efficiency, and costs about $1,149 a year to run in a mixed climate like Atlanta.

      SEER2
      16.0 Cooling efficiency over a season
      Below average · beats 26%
      HSPF2
      8.0 Heating efficiency over a season
      Below average · beats 12%
      EER2
      11.7 Cooling efficiency on a 95°F day
      Average · beats 43%
      Heat at 5°F
      17,800 BTU/h52% of its 47°F output
      Below average · beats 1%

      A good fit if…

      • You want a certified 3-ton central heat pump at a typical efficiency level.

      Think twice if…

      • You often see nights below 0°F - it is not cold-climate certified.
      • Cooling cost matters most - its SEER2 is below average for central heat pumps.
      • You mainly need heat - its HSPF2 is below average for central heat pumps.

      Calculate my running cost

      Details

      Specifications3 ton, R-454B
      General
      BrandFrigidaire
      Also sold asGibson
      Outdoor unit modelFSH4BF5M2SX36K
      SeriesFRIGIDAIRE FSH4BF SERIES
      TypeCentral heat pump
      Nominal size3 ton
      CompressorVariable-speed units run longer at low powerTwo-stage
      RefrigerantR-454B
      Connected (smart) capableNo
      On the market sinceDecember 19, 2024
      Last certifiedMay 15, 2025
      Cooling
      SEER2Seasonal efficiency, higher is better16.0 (range 16.0)
      EER2Efficiency at 95°F outdoors11.7
      Cooling capacity36,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better8.0
      Capacity at 47°F34,200 BTU/h
      Capacity at 17°F21,600 BTU/h
      Capacity at 5°F17,800 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.75
      ENERGY STAR cold climateNo
      Heating output as it gets colder52% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with B65VMMX3648K*C 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.
      B65VMMX3648K*C16.011.78.017,800217194122
      B65VMMX3648K*C16.011.78.017,800217447222
      Yearly running cost in 10 large cities$1,056-$2,725

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

      Questions5
      What is the SEER2 rating of the Frigidaire FSH4BF5M2SX36K?
      The Frigidaire FSH4BF5M2SX36K is rated at up to 16.0 SEER2 and 11.7 EER2 for cooling and up to 8.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
      Is the Frigidaire FSH4BF5M2SX36K good for cold climates?
      It is not cold-climate certified: none of its matchups meet the ENERGY STAR cold-climate criteria (a COP of at least 1.75 at 5°F among other limits). In places with frequent sub-zero nights, pick a cold-climate 3-ton model.
      How much does the Frigidaire FSH4BF5M2SX36K cost to run per year?
      At its rated efficiency it costs about $1,056-$2,725 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,288 in Phoenix and $2,266 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 Frigidaire FSH4BF5M2SX36K?
      ENERGY STAR lists 2 certified combinations for this outdoor unit. The highest-rated one uses B65VMMX3648K*C.
      What refrigerant does the Frigidaire FSH4BF5M2SX36K 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 $1,271/yrYou save $556/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 Frigidaire FSH4BF5M2SX36K
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $1,271
      Current system, per year
      $1,827
      You save per year
      $556
      Payback
      24.3 years
      Net after 10 years
      -$7,940

      Cooling $792Heating $479Electricity used: 7,943 kWhSaved vs. a minimum-efficiency heat pump: $126

      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 3 ton models

      See all 302 3 ton central heat pumps, ranked

      Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of May 15, 2025. How we use the data.