HVAC Rated
    Menu

      3.5-ton central heat pump · Performance

      Mainline MPP15AY42AJ2N

      Below average cooling and heating efficiency for a 3.5-ton central heat pump, and certified for cold climates.

      Ranks #78 of 138 3.5 ton central heat pumps for cooling efficiency, and costs about $1,308 a year to run in a mixed climate like Atlanta.

      SEER2
      16.0 Cooling efficiency over a season
      Below average · beats 26%
      HSPF2
      8.1 Heating efficiency over a season
      Below average · beats 20%
      EER2
      11.7 Cooling efficiency on a 95°F day
      Average · beats 43%
      Heat at 5°F
      19,300 BTU/h47% of its 47°F output
      Below average · beats 39%

      A good fit if…

      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 19,300 BTU/h at 5°F.
      • You want a choice of indoor units - 53 certified pairings.

      Think twice if…

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

      Calculate my running cost

      Details

      Specifications3.5 ton, R-454B
      General
      BrandMainline
      Outdoor unit modelMPP15AY42AJ2N
      SeriesPerformance
      TypeCentral heat pump
      Nominal size3.5 ton
      CompressorVariable-speed units run longer at low powerTwo-stage
      RefrigerantR-454B
      Connected (smart) capableNo
      On the market sinceDecember 23, 2024
      Last certifiedApril 9, 2025
      Cooling
      SEER2Seasonal efficiency, higher is better16.0 (range 15.2-16.0)
      EER2Efficiency at 95°F outdoors11.7
      Cooling capacity40,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better8.1
      Capacity at 47°F40,000 BTU/h
      Capacity at 17°F40,000 BTU/h
      Capacity at 5°F18,700-19,300 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater2.00
      ENERGY STAR cold climateYes
      Heating output as it gets colder47% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with TCFY4824STANM at the standard test temperatures, in BTU/h:

      Certified matchups53 indoor units

      The same outdoor unit scores differently with each indoor unit and furnace. Ask your installer for the AHRI reference number of the exact system you are quoted.

      Indoor unitFurnaceSEER2EER2HSPF2Heat @5°FAHRI ref.
      TCFY4824STANM · cold climateMP802W1255A24UH16.011.78.118,800216687721
      TCFY4821STANM · cold climateMP921W0855A21M415.211.78.119,200216687598
      TCFY4824STANM · cold climateMP802W0755A21UH15.211.78.118,900216687621
      TCFY4824STANM · cold climateMP801W1005A21UHN15.211.78.118,800216687624
      TCFY4824STANM · cold climateMP801W1005A21UHS15.211.78.118,800216687617
      TCFY4824STANM · cold climateMP802W1255A24DZ15.211.78.118,700216687626
      TCFY4824STANM · cold climateMP802W1505A24UH15.211.78.118,800216687625
      TCFY4821STANM · cold climateMP802W1005A21UH15.211.78.118,800216687627
      TCFY4821STANM · cold climateMP802W1004A17UH15.211.78.119,000216687629
      TCFY4821STANM · cold climateMP801W1005A21UHN15.211.78.118,800216687634
      TCFY4824STANM · cold climateMP801W0755A21UH15.211.78.118,900216687628
      TCFY4821STANM · cold climateMP802W0755A21DZ15.211.78.118,800216687635
      TCFY4824STANM · cold climateMP801W1255A24UH15.211.78.118,800216687630
      TCFY4821STANM · cold climateMP802W1005A21DZ15.211.78.118,700216687633
      TCFY4821STANM · cold climateMP801W0754A17DZ15.211.78.119,300216687631
      TCFY4821STANM · cold climateMP802W0755A21UH15.211.78.118,900216687632
      TCFY4821STANM · cold climateMP962W1005A21M415.211.78.119,100216687647
      TCFY4821STANM · cold climateMP801W1005A21UHS15.211.78.118,800216687639
      TCFY4821STANM · cold climateMP801W0755A21DZ15.211.78.118,800216687642
      TCFY4824STANM · cold climateMP802W0755A21DZ15.211.78.118,800216687636
      TCFY4821STANM · cold climateMP801W1004A17UH15.211.78.119,000216687638
      TCFY4824STANM · cold climateMP802W1005A21UH15.211.78.118,800216687637
      TCFY4821STANM · cold climateMP801W1005A21DZ15.211.78.118,700216687640
      TCFY4821STANM · cold climateMP802W0754A17UH15.211.78.118,800216687641
      TCFY4824STANM · cold climateMP962W1155A24M415.211.78.118,800216687652
      TCFY4824STANM · cold climateMP962W0705A21M415.211.78.119,100216687712
      TCFY4824STANM · cold climateMP962W1005A21M415.211.78.119,100216687651
      TCFY4821STANM · cold climateMP962W0855A21M415.211.78.119,200216687649
      TCFY4824STANM · cold climateMP962W0855A21M415.211.78.119,200216687650
      TCFY4821STANM · cold climateMP962W0705A21M415.211.78.119,100216687648
      TCFY4824STANM · cold climateMP921W0705A21M415.211.78.119,100216687599
      TCFY4821STANM · cold climateMP921W1005A21M415.211.78.119,100216687602
      TCFY4821STANM · cold climateMP921W0705A21M415.211.78.119,100216687601
      TCFY4821STANM · cold climateMP951W1005A21M415.211.78.119,100216687600
      TCFY4824STANM · cold climateMP951W1005A21UH15.211.78.119,000216687604
      TCFY4824STANM · cold climateMP951W1005A21M415.211.78.119,100216687606
      TCFY4824STANM · cold climateMP921W1005A21M415.211.78.119,100216687608
      TCFY4824STANM · cold climateMP951W0855A21M415.211.78.119,200216687610
      TCFY4824STANM · cold climateMP921W0855A21M415.211.78.119,200216687603
      TCFY4824STANM · cold climateMP951W0705A21M415.211.78.119,100216687605
      TCFY4824STANM · cold climateMP951W1155A24M415.211.78.118,800216687607
      TCFY4824STANM · cold climateMP921W1155A24M415.211.78.118,800216687609
      TCFY4821STANM · cold climateMP951W1005A21UH15.211.78.119,000216687612
      TCFY4821STANM · cold climateMP801W0754A17UH15.211.78.118,800216687616
      TCFY4821STANM · cold climateMP951W0855A21M415.211.78.119,200216687611
      TCFY4821STANM · cold climateMP801W0755A21UH15.211.78.118,900216687614
      TCFY4824STANM · cold climateMP801W1505A24UH15.211.78.118,800216687615
      TCFY4821STANM · cold climateMP951W0705A21M415.211.78.119,100216687613
      TCFY4824STANM · cold climateMP801W0755A21DZ15.211.78.118,800216687619
      TCFY4824STANM · cold climateMP801W1255A24DZ15.211.78.118,700216687618
      TCFY4824STANM · cold climateMP802W1005A21DZ15.211.78.118,700216687623
      TCFY4821STANM · cold climateMP802W0754A17DZ15.211.78.119,300216687620
      TCFY4824STANM · cold climateMP801W1005A21DZ15.211.78.118,700216687622
      Yearly running cost in 10 large cities$1,175-$3,124

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

      Questions5
      What is the SEER2 rating of the Mainline MPP15AY42AJ2N?
      The Mainline MPP15AY42AJ2N is rated at up to 16.0 SEER2 and 11.7 EER2 for cooling and up to 8.1 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 53 certified matchups SEER2 ranges from 15.2-16.0.
      Is the Mainline MPP15AY42AJ2N good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 19,300 BTU/h at 5°F with a COP of 2.00, so it is still 2.0 times as efficient as electric resistance heat at that temperature.
      How much does the Mainline MPP15AY42AJ2N cost to run per year?
      At its rated efficiency it costs about $1,175-$3,124 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,446 in Phoenix and $2,608 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 Mainline MPP15AY42AJ2N?
      ENERGY STAR lists 53 certified combinations for this outdoor unit. The highest-rated ones use TCFY4824STANM, TCFY4821STANM.
      What refrigerant does the Mainline MPP15AY42AJ2N 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 $1,433/yrYou save $629/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 Mainline MPP15AY42AJ2N
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $1,433
      Current system, per year
      $2,063
      You save per year
      $629
      Payback
      23.8 years
      Net after 10 years
      -$8,706

      Cooling $880Heating $553Electricity used: 8,957 kWhSaved vs. a minimum-efficiency heat pump: $149

      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 3.5 ton models

      See all 138 3.5 ton central heat pumps, ranked

      Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of April 9, 2025. How we use the data.