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      18,000 BTU mini-split heat pump · KUSAC181A

      LG KUSAC181A

      Below average cooling and heating efficiency for a 18,000 BTU mini-split heat pump, and certified for cold climates.

      Ranks #363 of 465 18,000 BTU mini-splits for cooling efficiency, and costs about $503 a year to run in a mixed climate like Atlanta.

      SEER2
      21.0 Cooling efficiency over a season
      Below average · beats 30%
      HSPF2
      9.4 Heating efficiency over a season
      Below average · beats 19%
      EER2
      12.5 Cooling efficiency on a 95°F day
      Average · beats 44%
      Heat at 5°F
      13,300 BTU/h70% of its 47°F output
      Below average · beats 9%

      A good fit if…

      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 13,300 BTU/h at 5°F.
      • You want steady temperatures and quiet running - the compressor varies its speed.

      Think twice if…

      • Cooling cost matters most - its SEER2 is below average for mini-splits.
      • You mainly need heat - its HSPF2 is below average for mini-splits.

      Calculate my running cost

      Details

      Specifications18,000 BTU, R-32
      General
      BrandLG
      Outdoor unit modelKUSAC181A
      SeriesKUSAC181A
      TypeMini-split heat pump
      Nominal size18,000 BTU
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-32
      Connected (smart) capableNo
      On the market sinceDecember 23, 2024
      Last certifiedDecember 2, 2025
      Cooling
      SEER2Seasonal efficiency, higher is better21.0 (range 21.0)
      EER2Efficiency at 95°F outdoors12.5
      Cooling capacity18,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better9.4
      Capacity at 47°F19,000 BTU/h
      Capacity at 17°F11,600 BTU/h
      Capacity at 5°F13,300 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.80
      ENERGY STAR cold climateYes
      Heating output as it gets colder70% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with KNSAC181A at the standard test temperatures, in BTU/h:

      Certified matchups1 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.
      KNSAC181A · cold climate21.012.59.413,300214931161
      Same unit, other model numbers3

      These model numbers have exactly the same certified ratings and matchups as the LG KUSAC181A: the same equipment under another brand, or a variant code for voltage, colour or market. Everything on this page applies to them.

      • LG KUSAD181A
      • LG KUSAD181C
      • LG KUSAH181A
      Yearly running cost in 10 large cities$405-$1,238

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

      Questions6
      What is the SEER2 rating of the LG KUSAC181A?
      The LG KUSAC181A is rated at up to 21.0 SEER2 and 12.5 EER2 for cooling and up to 9.4 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
      Is the LG KUSAC181A good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 13,300 BTU/h at 5°F with a COP of 1.80, so it is still 1.8 times as efficient as electric resistance heat at that temperature.
      How much does the LG KUSAC181A cost to run per year?
      At its rated efficiency it costs about $405-$1,238 a year in electricity in large U.S. cities, depending on climate and local rates - for example $521 in Phoenix and $1,051 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
      Is the LG KUSAC181A the same as the LG KUSAD181A?
      Yes, as far as the certified ratings go. ENERGY STAR lists 4 model numbers with identical efficiency, capacity and matchups, which means the same outdoor unit sold under a different brand or with a minor variant code (voltage, colour or region). The full list is on this page.
      Which indoor units work with the LG KUSAC181A?
      ENERGY STAR lists 1 certified combination for this outdoor unit. The highest-rated one uses KNSAC181A.
      What refrigerant does the LG KUSAC181A 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 $528/yrYou save $416/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 KUSAC181A
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $528
      Current system, per year
      $944
      You save per year
      $416
      Payback
      16.8 years
      Net after 10 years
      -$2,836

      Cooling $302Heating $226Electricity used: 3,301 kWhSaved vs. a minimum-efficiency heat pump: $199

      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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      Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of December 2, 2025. How we use the data.