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      4-ton central heat pump · KUSXB481A

      LG KUSXB481A

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

      Ranks #3 of 319 4 ton central heat pumps for cooling efficiency, and costs about $1,217 a year to run in a mixed climate like Atlanta.

      SEER2
      21.2 Cooling efficiency over a season
      Excellent · beats 98%
      HSPF2
      10.4 Heating efficiency over a season
      Excellent · beats 94%
      EER2
      12.1 Cooling efficiency on a 95°F day
      Very good · beats 74%
      Heat at 5°F
      40,000 BTU/h78% of its 47°F output
      Below average · beats 29%

      A good fit if…

      • You want low cooling bills - its SEER2 beats 98% of central heat pumps.
      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 40,000 BTU/h at 5°F.
      • It will heat most of the year - its HSPF2 beats 94% of central heat pumps.
      • You want steady temperatures and quiet running - the compressor varies its speed.

      Think twice if…

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

      Calculate my running cost

      Details

      Specifications4 ton, R-32
      General
      BrandLG
      Outdoor unit modelKUSXB481A
      SeriesKUSXB481A
      TypeCentral heat pump
      Nominal size4 ton
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-32
      Connected (smart) capableNo
      On the market sinceDecember 2, 2024
      Last certifiedApril 22, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better21.2 (range 15.2-21.2)
      EER2Efficiency at 95°F outdoors10.5-12.1
      Cooling capacity45,500-48,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better8.3-10.4
      Capacity at 47°F48,000-52,000 BTU/h
      Capacity at 17°F31,000-32,200 BTU/h
      Capacity at 5°F37,000-40,000 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.80-1.96
      ENERGY STAR cold climateYes
      Heating output as it gets colder78% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with KNSCB481A at the standard test temperatures, in BTU/h:

      Certified matchups8 indoor units

      The same outdoor unit scores differently with each indoor unit and furnace. Ask your installer for the AHRI reference number of the exact system you are quoted.

      Indoor unitFurnaceSEER2EER2HSPF2Heat @5°FAHRI ref.
      KNSCB481A · cold climate-21.212.110.440,000214836842
      KNSLB481A · cold climate-18.011.79.438,500215588580
      KNSLB481A · cold climate-18.011.79.438,500217284916
      KNSJB481A · cold climate-17.511.79.140,000214836843
      LKMMA48C1 · cold climateLNA**100C117.011.09.437,000217284967
      LKMMA48D1 · cold climateLNA**120D117.011.09.437,000217284968
      LKMMA48D1 · cold climate-15.511.08.538,000216445251
      LKMMA48C1 · cold climate-15.210.58.338,000216445250
      Yearly running cost in 10 large cities$1,013-$2,972

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

      Questions5
      What is the SEER2 rating of the LG KUSXB481A?
      The LG KUSXB481A is rated at up to 21.2 SEER2 and 12.1 EER2 for cooling and up to 10.4 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 8 certified matchups SEER2 ranges from 15.2-21.2.
      Is the LG KUSXB481A good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 40,000 BTU/h at 5°F with a COP of 1.96, so it is still 2.0 times as efficient as electric resistance heat at that temperature.
      How much does the LG KUSXB481A cost to run per year?
      At its rated efficiency it costs about $1,013-$2,972 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,285 in Phoenix and $2,511 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 LG KUSXB481A?
      ENERGY STAR lists 8 certified combinations for this outdoor unit. The highest-rated ones use KNSCB481A, KNSLB481A, KNSJB481A.
      What refrigerant does the LG KUSXB481A use?
      It uses 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 $1,294/yrYou save $1,126/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 LG KUSXB481A
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $1,294
      Current system, per year
      $2,420
      You save per year
      $1,126
      Payback
      15.1 years
      Net after 10 years
      -$5,742

      Cooling $755Heating $538Electricity used: 8,087 kWhSaved vs. a minimum-efficiency heat pump: $573

      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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      See all 319 4 ton central heat pumps, ranked

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