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      18,000 BTU mini-split heat pump · MAGNUS

      MIRAGE OMZH181C

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

      Ranks #146 of 465 18,000 BTU mini-splits for cooling efficiency, and costs about $443 a year to run in a mixed climate like Atlanta.

      SEER2
      23.0 Cooling efficiency over a season
      Average · beats 62%
      HSPF2
      10.0 Heating efficiency over a season
      Average · beats 43%
      EER2
      12.5 Cooling efficiency on a 95°F day
      Average · beats 44%
      Heat at 5°F
      13,600 BTU/h72% 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 13,600 BTU/h at 5°F.
      • 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

      Specifications18,000 BTU, R-454B
      General
      BrandMIRAGE
      Outdoor unit modelOMZH181C
      SeriesMAGNUS
      TypeMini-split heat pump
      Nominal size18,000 BTU
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-454B
      Connected (smart) capableNo
      On the market sinceJanuary 1, 2025
      Last certifiedJuly 6, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better23.0 (range 19.0-23.0)
      EER2Efficiency at 95°F outdoors11.0-12.5
      Cooling capacity11,000-18,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better8.4-10.0
      Capacity at 47°F12,000-19,000 BTU/h
      Capacity at 17°F10,200-15,000 BTU/h
      Capacity at 5°F8,800-13,600 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.80
      ENERGY STAR cold climateYes
      Heating output as it gets colder72% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with IMZH181C at the standard test temperatures, in BTU/h:

      Certified matchups4 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.
      IMZH181C Mirage · cold climate23.012.510.013,600216772354
      CGFH181C Mirage · cold climate20.511.08.513,200218471031
      DGFH181C Mirage · cold climate20.311.010.013,200218471409
      - Mirage · cold climate19.011.08.48,800218471034
      Yearly running cost in 10 large cities$350-$1,097

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

      Questions5
      What is the SEER2 rating of the MIRAGE OMZH181C?
      The MIRAGE OMZH181C is rated at up to 23.0 SEER2 and 12.5 EER2 for cooling and up to 10.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 4 certified matchups SEER2 ranges from 19.0-23.0.
      Is the MIRAGE OMZH181C good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 13,600 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 MIRAGE OMZH181C cost to run per year?
      At its rated efficiency it costs about $350-$1,097 a year in electricity in large U.S. cities, depending on climate and local rates - for example $454 in Phoenix and $934 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 MIRAGE OMZH181C?
      ENERGY STAR lists 4 certified combinations for this outdoor unit. The highest-rated ones use Mirage IMZH181C, Mirage CGFH181C, Mirage DGFH181C.
      What refrigerant does the MIRAGE OMZH181C 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 $462/yrYou save $431/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 MIRAGE OMZH181C
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $462
      Current system, per year
      $893
      You save per year
      $431
      Payback
      15.1 years
      Net after 10 years
      -$2,188

      Cooling $260Heating $202Electricity used: 2,886 kWhSaved vs. a minimum-efficiency heat pump: $225

      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 July 6, 2026. How we use the data.