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      18,000 BTU mini-split heat pump · Perfect Aire Quick Connect

      PerfectAire 4PAMSHHQC18-MZO2

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

      Ranks #223 of 465 18,000 BTU mini-splits for cooling efficiency, and costs about $459 a year to run in a mixed climate like Atlanta.

      SEER2
      22.0 Cooling efficiency over a season
      Average · beats 48%
      HSPF2
      10.0 Heating efficiency over a season
      Average · beats 43%
      EER2
      13.3 Cooling efficiency on a 95°F day
      Very good · beats 70%
      Heat at 5°F
      18,000 BTU/h100% of its 47°F output
      Below average · beats 38%

      A good fit if…

      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 18,000 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
      BrandPerfectAire
      Also sold asOLMO, Hessaire, STATUS
      Outdoor unit model4PAMSHHQC18-MZO2
      SeriesPerfect Aire Quick Connect
      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 sinceSeptember 14, 2026
      Last certifiedSeptember 22, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better22.0 (range 22.0)
      EER2Efficiency at 95°F outdoors13.3
      Cooling capacity18,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better10.0
      Capacity at 47°F18,000 BTU/h
      Capacity at 17°F11,500 BTU/h
      Capacity at 5°F18,000 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.99
      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 best matchup 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.
      - Perfect Aire · cold climate22.013.310.018,000218792068
      Same unit, other model numbers3

      These model numbers have exactly the same certified ratings and matchups as the PerfectAire 4PAMSHHQC18-MZO2: the same equipment under another brand, or a variant code for voltage, colour or market. Everything on this page applies to them.

      Yearly running cost in 10 large cities$386-$1,116

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

      Questions5
      What is the SEER2 rating of the PerfectAire 4PAMSHHQC18-MZO2?
      The PerfectAire 4PAMSHHQC18-MZO2 is rated at up to 22.0 SEER2 and 13.3 EER2 for cooling and up to 10.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
      Is the PerfectAire 4PAMSHHQC18-MZO2 good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 18,000 BTU/h at 5°F with a COP of 1.99, so it is still 2.0 times as efficient as electric resistance heat at that temperature.
      How much does the PerfectAire 4PAMSHHQC18-MZO2 cost to run per year?
      At its rated efficiency it costs about $386-$1,116 a year in electricity in large U.S. cities, depending on climate and local rates - for example $487 in Phoenix and $941 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
      Is the PerfectAire 4PAMSHHQC18-MZO2 the same as the OLMO OS-RMS18-230VO?
      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.
      What refrigerant does the PerfectAire 4PAMSHHQC18-MZO2 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 $490/yrYou save $439/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 PerfectAire 4PAMSHHQC18-MZO2
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $490
      Current system, per year
      $928
      You save per year
      $439
      Payback
      16.0 years
      Net after 10 years
      -$2,615

      Cooling $288Heating $202Electricity used: 3,060 kWhSaved vs. a minimum-efficiency heat pump: $222

      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 September 22, 2026. How we use the data.