HVAC Rated
    Menu

      18,000 BTU mini-split heat pump · Standard SZ Wall-Mount

      Samsung MWHE018S6S-1P

      Below average cooling and heating efficiency for a 18,000 BTU mini-split heat pump, but not rated for cold climates.

      Ranks #442 of 465 18,000 BTU mini-splits for cooling efficiency, and costs about $572 a year to run in a mixed climate like Atlanta.

      SEER2
      19.0 Cooling efficiency over a season
      Below average · beats 9%
      HSPF2
      9.0 Heating efficiency over a season
      Below average · beats 10%
      EER2
      12.9 Cooling efficiency on a 95°F day
      Average · beats 56%
      Heat at 5°F
      13,400 BTU/h64% of its 47°F output
      Very good · beats 74%

      A good fit if…

      • You want steady temperatures and quiet running - the compressor varies its speed.

      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 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
      BrandSamsung
      Outdoor unit modelMWHE018S6S-1P
      SeriesStandard SZ Wall-Mount
      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 sinceOctober 9, 2026
      Last certifiedJuly 29, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better19.0 (range 19.0)
      EER2Efficiency at 95°F outdoors12.9
      Cooling capacity18,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better9.0
      Capacity at 47°F21,000 BTU/h
      Capacity at 17°F16,000 BTU/h
      Capacity at 5°F13,400 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater2.16
      ENERGY STAR cold climateNo
      Heating output as it gets colder64% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with MWSE018S6-1P 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.
      MWSE018S6-1P SAMSUNG19.012.99.013,400218691696
      Yearly running cost in 10 large cities$449-$1,419

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

      Questions5
      What is the SEER2 rating of the Samsung MWHE018S6S-1P?
      The Samsung MWHE018S6S-1P is rated at up to 19.0 SEER2 and 12.9 EER2 for cooling and up to 9.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
      Is the Samsung MWHE018S6S-1P 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 18,000 BTU model.
      How much does the Samsung MWHE018S6S-1P cost to run per year?
      At its rated efficiency it costs about $449-$1,419 a year in electricity in large U.S. cities, depending on climate and local rates - for example $584 in Phoenix and $1,209 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 Samsung MWHE018S6S-1P?
      ENERGY STAR lists 1 certified combination for this outdoor unit. The highest-rated one uses SAMSUNG MWSE018S6-1P.
      What refrigerant does the Samsung MWHE018S6S-1P 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 $595/yrYou save $382/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 Samsung MWHE018S6S-1P
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $595
      Current system, per year
      $977
      You save per year
      $382
      Payback
      18.3 years
      Net after 10 years
      -$3,176

      Cooling $333Heating $261Electricity used: 3,718 kWhSaved vs. a minimum-efficiency heat pump: $162

      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 18,000 BTU models

      See all 465 18,000 BTU mini-splits, ranked

      Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of July 29, 2026. How we use the data.