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      3.5-ton central heat pump · KUSXA422A

      LG KUSXA422A

      Very good cooling and heating efficiency for a 3.5-ton central heat pump, and certified for cold climates.

      Ranks #17 of 138 3.5 ton central heat pumps for cooling efficiency, and costs about $1,211 a year to run in a mixed climate like Atlanta.

      SEER2
      19.0 Cooling efficiency over a season
      Very good · beats 85%
      HSPF2
      9.8 Heating efficiency over a season
      Very good · beats 79%
      EER2
      12.5 Cooling efficiency on a 95°F day
      Very good · beats 80%
      Heat at 5°F
      46,000 BTU/h100% of its 47°F output
      Below average · beats 39%

      A good fit if…

      • You want low cooling bills - its SEER2 beats 85% of central heat pumps.
      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 46,000 BTU/h at 5°F.
      • It will heat most of the year - its HSPF2 beats 79% 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

      Specifications3.5 ton, R-32
      General
      BrandLG
      Outdoor unit modelKUSXA422A
      SeriesKUSXA422A
      TypeCentral heat pump
      Nominal size3.5 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 better19.0 (range 16.0-19.0)
      EER2Efficiency at 95°F outdoors11.7-12.5
      Cooling capacity41,000-42,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better8.9-9.8
      Capacity at 47°F44,000-46,000 BTU/h
      Capacity at 17°F29,000-29,800 BTU/h
      Capacity at 5°F41,000-46,000 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.90-2.00
      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 KNSLB421A at the standard test temperatures, in BTU/h:

      Certified matchups4 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.
      KNSLB421A · cold climate-19.012.59.846,000215735573
      KNSLB421A · cold climate-19.012.59.846,000217284918
      LKMMA42C1 · cold climateLNA**100C118.211.79.842,000217284954
      LKMMA42C1 · cold climate-16.011.98.941,000216445260
      Yearly running cost in 10 large cities$1,041-$2,929

      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 KUSXA422A?
      The LG KUSXA422A is rated at up to 19.0 SEER2 and 12.5 EER2 for cooling and up to 9.8 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 4 certified matchups SEER2 ranges from 16.0-19.0.
      Is the LG KUSXA422A good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 46,000 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 LG KUSXA422A cost to run per year?
      At its rated efficiency it costs about $1,041-$2,929 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,303 in Phoenix and $2,463 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 KUSXA422A?
      ENERGY STAR lists 4 certified combinations for this outdoor unit. The highest-rated ones use KNSLB421A, LKMMA42C1.
      What refrigerant does the LG KUSXA422A 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 $1,304/yrYou save $927/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 KUSXA422A
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $1,304
      Current system, per year
      $2,231
      You save per year
      $927
      Payback
      17.3 years
      Net after 10 years
      -$6,727

      Cooling $778Heating $526Electricity used: 8,149 kWhSaved vs. a minimum-efficiency heat pump: $417

      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 3.5 ton models

      See all 138 3.5 ton central heat pumps, ranked

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