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      12,000 BTU mini-split heat pump · UPAC

      Guardian UPC12CN23STG1

      Average cooling and heating efficiency for a 12,000 BTU mini-split heat pump, and certified for cold climates.

      Ranks #290 of 394 12,000 BTU mini-splits for cooling efficiency, and costs about $296 a year to run in a mixed climate like Atlanta.

      SEER2
      22.0 Cooling efficiency over a season
      Average · beats 48%
      HSPF2
      10.5 Heating efficiency over a season
      Average · beats 61%
      EER2
      12.0 Cooling efficiency on a 95°F day
      Below average · beats 25%
      Heat at 5°F
      12,000 BTU/h100% 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 12,000 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

      Specifications12,000 BTU, R-454B
      General
      BrandGuardian
      Also sold asColeman, Luxaire
      Outdoor unit modelUPC12CN23STG1
      SeriesUPAC
      TypeMini-split heat pump
      Nominal size12,000 BTU
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-454B
      Connected (smart) capableNo
      On the market sinceAugust 28, 2024
      Last certifiedApril 27, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better22.0 (range 19.5-22.0)
      EER2Efficiency at 95°F outdoors11.7-12.0
      Cooling capacity12,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better9.5-10.5
      Capacity at 47°F12,000 BTU/h
      Capacity at 17°F8,700-8,900 BTU/h
      Capacity at 5°F12,000 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.80
      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 UNI12HW23STG1 at the standard test temperatures, in BTU/h:

      Certified matchups9 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.
      UNI12HW23STG1 GUARDIAN · cold climate22.012.010.512,000215439627
      UNI12HW23STG1 Coleman · cold climate22.012.010.512,000216572158
      UNI12HW23STG1 LUXAIRE · cold climate22.012.010.512,000216572169
      UNI12CS23STG1 GUARDIAN · cold climate20.012.09.512,000215449567
      UNI12CS23STG1 Coleman · cold climate20.012.09.512,000216566081
      UNI12CS23STG1 LUXAIRE · cold climate20.012.09.512,000216566085
      UNI12DT23STG1 GUARDIAN · cold climate19.511.79.512,000215449569
      UNI12DT23STG1 Coleman · cold climate19.511.79.512,000216566083
      UNI12DT23STG1 LUXAIRE · cold climate19.511.79.512,000216566087
      Yearly running cost in 10 large cities$257-$715

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

      Questions5
      What is the SEER2 rating of the Guardian UPC12CN23STG1?
      The Guardian UPC12CN23STG1 is rated at up to 22.0 SEER2 and 12.0 EER2 for cooling and up to 10.5 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 9 certified matchups SEER2 ranges from 19.5-22.0.
      Is the Guardian UPC12CN23STG1 good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 12,000 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 Guardian UPC12CN23STG1 cost to run per year?
      At its rated efficiency it costs about $257-$715 a year in electricity in large U.S. cities, depending on climate and local rates - for example $320 in Phoenix and $600 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 Guardian UPC12CN23STG1?
      ENERGY STAR lists 9 certified combinations for this outdoor unit. The highest-rated ones use GUARDIAN UNI12HW23STG1, Coleman UNI12HW23STG1, LUXAIRE UNI12HW23STG1.
      What refrigerant does the Guardian UPC12CN23STG1 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 $320/yrYou save $299/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 Guardian UPC12CN23STG1
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $320
      Current system, per year
      $619
      You save per year
      $299
      Payback
      15.1 years
      Net after 10 years
      -$1,513

      Cooling $192Heating $128Electricity used: 2,000 kWhSaved vs. a minimum-efficiency heat pump: $155

      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 April 27, 2026. How we use the data.