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      3.5-ton central heat pump · LX SERIES

      Luxaire THF2B42T21

      Below average cooling and heating efficiency for a 3.5-ton central heat pump, but not rated for cold climates.

      Ranks #76 of 138 3.5 ton central heat pumps for cooling efficiency, and costs about $1,315 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
      12.0 Cooling efficiency on a 95°F day
      Average · beats 64%
      Heat at 5°F
      22,600 BTU/h55% of its 47°F output
      Excellent · beats 96%

      A good fit if…

      • You want a choice of indoor units - 2,200 certified pairings.

      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 central heat pumps.
      • You mainly need heat - its HSPF2 is below average for central heat pumps.
      • You want the newest refrigerant - it uses R-410A, which is being phased down.

      Calculate my running cost

      Details

      Specifications3.5 ton, R-410A
      General
      BrandLuxaire
      Also sold asColeman, Fraser-Johnston, CHAMPION HEATING AND COOLING, Johnson Controls
      Outdoor unit modelTHF2B42T21
      SeriesLX SERIES
      TypeCentral heat pump
      Nominal size3.5 ton
      CompressorVariable-speed units run longer at low powerTwo-stage
      RefrigerantR-410A
      Connected (smart) capableNo
      On the market sinceMay 18, 2023
      Last certifiedJuly 17, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better16.0 (range 15.2-16.0)
      EER2Efficiency at 95°F outdoors11.7-12.0
      Cooling capacity39,500-42,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better7.8-8.1
      Capacity at 47°F37,400-41,000 BTU/h
      Capacity at 17°F24,200-26,600 BTU/h
      Capacity at 5°F18,400-22,600 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.98-2.42
      ENERGY STAR cold climateNo
      Heating output as it gets colder55% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with XAHC48FBCN1 at the standard test temperatures, in BTU/h:

      Certified matchups2,200 indoor units

      The same outdoor unit scores differently with each indoor unit and furnace. The 60 highest-rated of 2,200 are shown. Ask your installer for the AHRI reference number of the exact system you are quoted.

      Indoor unitFurnaceSEER2EER2HSPF2Heat @5°FAHRI ref.
      XAHC48FBCN1Z8ES080B12LMPS116.012.08.122,000212485804
      XAHC48FBCN1Z8ES080B12LMPS116.012.08.122,000212485800
      XAHC48FBCN1Z8ES120C16LMPS116.011.78.122,400212482940
      XAFD48FBCN1Z8ES080C20LMPS116.011.78.121,000212485784
      XAHC48FBCN1Z8ET080C16LMPS116.012.08.122,200212416022
      XAHC48FBCN1Z8ES080B12LMPS116.012.08.122,000212485801
      XAHC48FBCN1Z8ET100C20LMPS116.012.08.122,200212415930
      XAHD48FBCN1Z8ES100C20LMPS116.012.08.122,200212485758
      XAHD48FBCN1Z8ES080C16LMPS116.012.08.122,200212475874
      XAHC48FBCN1Z8ES100B12LMPS116.011.78.122,200212475835
      XAFD48FBCN1Z8ES080C20LMPS116.011.78.121,000212485790
      XAHD48FBCN1Z8ES080C16LMPS116.012.08.122,200212475866
      XAHD48FBCN1Z8ES100C16LMPS116.012.08.122,200212478283
      XAFC48FBCN1Z8ES080C16SMPS116.011.78.121,200212416383
      XAHC48FBCN1Z8ES080C16LMPS116.012.08.122,200212483059
      XAHD48FBCN1Z8ES080C20LMPS116.012.08.122,200212478297
      XAFD48FBCN1Z8ES080C20SMPS116.011.78.121,000212416326
      XAHC48FBCN1Z8ET120C20LMPS116.012.08.122,000212415886
      XAHC48FBCN1Z8ES120C16LMPS116.011.78.122,400212482936
      XAFD48FBCN1Z8ES080C16LMPS116.011.78.121,200212478308
      XAHD48FBCN1Z8ET080C16LMPS116.012.08.122,200212416014
      XAHC48FBCN1Z8ES080C16LMPS116.012.08.122,200212483056
      XAHD48FBCN1Z8ET080C16LMPS116.012.08.122,200212416010
      XAFD48FBCN1Z8ES080C16LMPS116.011.78.121,200212478314
      XAFC48FXXN1+TXVZ8ET080C16LMPS116.012.08.121,000212416035
      XAHC48FBCN1Z8ET080C16LMPS116.012.08.122,200212416024
      XAHC48FBCN1Z8ES080C16LMPS116.012.08.122,200212483064
      XAFD48FBCN1Z8ES080C16SMPS116.011.78.121,200212416370
      XAFC48FXXN1+TXVZ8ET120C20LMPS116.011.78.120,800212415904
      XAHD48FBCN1Z8ES080C16SMPS116.012.08.122,200212416354
      XAFC48FBCN1Z8ET120C20LMPS116.011.78.120,800212415907
      XAHD48FBCN1Z8ES080C20LMPS116.012.08.122,200212478296
      XAFD48FBCN1Z8ET120C20LMPS116.011.78.121,200212415898
      XAHD48FBCN1Z8ES100C16LMPS116.012.08.122,200212478281
      XAHD48FBCN1Z8ES100C16LMPS116.012.08.122,200212478282
      XAFC48FXXN1+TXVZ8ES080C20SMPS116.011.78.121,000212416332
      XAHD48FBCN1Z8ES080C20LMPS116.012.08.122,200212478295
      XAHD48FBCN1Z8ES100C16LMPS116.012.08.122,200212478280
      XAHD48FBCN1Z8ES080C16SMPS116.012.08.122,200212416350
      XAHD48FBCN1Z8ET100C16LMPS116.012.08.122,000212415968
      XAFC48FXXN1+TXVZ8ES080C16SMPS116.011.78.121,200212416379
      XAHC48FBCN1Z8ES080C16LMPS116.012.08.122,200212483061
      XAFD48FBCN1Z8ET120C20LMPS116.011.78.121,200212415896
      XAFC48FBCN1Z8ET080C16LMPS116.012.08.121,000212416041
      XAFD48FBCN1Z8ET080C16LMPS116.012.08.121,000212416034
      XAHD48FBCN1Z8ES130D20SMPS116.012.08.122,000212416080
      XAHC48FBCN1Z8ES080B12SMPS116.012.08.122,000212416397
      XAFC48FXXN1+TXVZ8ES080C16SMPS116.011.78.121,200212416376
      XAFC48FXXN1+TXVZ8ES120C16SMPS116.011.78.121,400212416174
      XAHD48FBCN1Z8ES080C16LMPS116.012.08.122,200212475862
      XAFC48FBCN1Z8ES080C20SMPS116.011.78.121,000212416335
      XAFD48FBCN1Z8ES080C16SMPS116.011.78.121,200212416371
      XAFC48FBCN1Z8ET080C16LMPS116.012.08.121,000212416042
      XAFC48FBCN1Z8ET080C16LMPS116.012.08.121,000212416040
      XAHC48FBCN1Z8ES100B12SMPS116.011.78.122,200212416281
      XAHD48FBCN1Z8ES100C20LMPS116.012.08.122,200212485757
      XAHC48FBCN1Z8ES120C16LMPS116.011.78.122,400212482950
      XAFD48FBCN1Z8ES080C20LMPS116.011.78.121,000212485785
      XAHC48FBCN1Z8ES120C16LMPS116.011.78.122,400212482929
      XAHD48FBCN1Z8ET100C16LMPS116.012.08.122,000212415967
      Yearly running cost in 10 large cities$1,189-$3,131

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

      Questions5
      What is the SEER2 rating of the Luxaire THF2B42T21?
      The Luxaire THF2B42T21 is rated at up to 16.0 SEER2 and 12.0 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 2200 certified matchups SEER2 ranges from 15.2-16.0.
      Is the Luxaire THF2B42T21 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 3.5-ton model.
      How much does the Luxaire THF2B42T21 cost to run per year?
      At its rated efficiency it costs about $1,189-$3,131 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,459 in Phoenix and $2,611 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 Luxaire THF2B42T21?
      ENERGY STAR lists 2200 certified combinations for this outdoor unit. The highest-rated ones use XAHC48FBCN1, XAFD48FBCN1, XAHD48FBCN1.
      What refrigerant does the Luxaire THF2B42T21 use?
      It uses R-410A. R-410A is being phased down under the EPA AIM Act, and new systems are moving to R-454B and 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 $1,444/yrYou save $636/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 Luxaire THF2B42T21
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $1,444
      Current system, per year
      $2,080
      You save per year
      $636
      Payback
      23.6 years
      Net after 10 years
      -$8,640

      Cooling $891Heating $553Electricity used: 9,026 kWhSaved vs. a minimum-efficiency heat pump: $150

      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 July 17, 2026. How we use the data.