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      3-ton central heat pump · Elite EL21KLV SERIES

      Lennox EL21KLV-036-230A

      Excellent cooling and heating efficiency for a 3-ton central heat pump, and certified for cold climates.

      Ranks #25 of 302 3 ton central heat pumps for cooling efficiency, and costs about $829 a year to run in a mixed climate like Atlanta.

      SEER2
      20.0 Cooling efficiency over a season
      Excellent · beats 94%
      HSPF2
      10.4 Heating efficiency over a season
      Excellent · beats 94%
      EER2
      11.7 Cooling efficiency on a 95°F day
      Average · beats 43%
      Heat at 5°F
      25,400 BTU/h76% of its 47°F output
      Excellent · beats 98%

      A good fit if…

      • You want low cooling bills - its SEER2 beats 94% of central heat pumps.
      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 25,400 BTU/h at 5°F.
      • It will heat most of the year - its HSPF2 beats 94% of central heat pumps.
      • 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

      Specifications3 ton, R-454B
      General
      BrandLennox
      Outdoor unit modelEL21KLV-036-230A
      SeriesElite EL21KLV SERIES
      TypeCentral heat pump
      Nominal size3 ton
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-454B
      Connected (smart) capableNo
      On the market sinceMarch 7, 2025
      Last certifiedSeptember 30, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better20.0 (range 15.2-20.0)
      EER2Efficiency at 95°F outdoors11.0-12.2
      Cooling capacity31,800-34,800 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better8.5-10.4
      Capacity at 47°F30,000-35,400 BTU/h
      Capacity at 17°F26,600-32,400 BTU/h
      Capacity at 5°F18,400-25,400 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.84-2.48
      ENERGY STAR cold climateYes
      Heating output as it gets colder76% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with CBK48MVT-036-230- at the standard test temperatures, in BTU/h:

      Certified matchups299 indoor units

      The same outdoor unit scores differently with each indoor unit and furnace. The 60 highest-rated of 299 are shown. Ask your installer for the AHRI reference number of the exact system you are quoted.

      Indoor unitFurnaceSEER2EER2HSPF2Heat @5°FAHRI ref.
      CBK48MVT-036-230- · cold climate-20.011.710.025,400217117000
      CBK45UHVT-042-230- · cold climate-20.012.29.023,800217121579
      CK40[C,U]T-30B-**+TDRSL280UH090V36B*19.511.710.422,800217443242
      CK40DT-30/36C-**+TDRSLP99DF090XV36C*19.511.29.419,500217443303
      CK40DT-30/36B-**+TDRSLP99DF070XV36B*19.511.29.219,200217443265
      CBK45UHET-042-230- · cold climate-19.511.78.524,400217121968
      CBK45UHVT-036-230- · cold climate-19.512.08.524,200217121970
      CK40[C,U]T-30A-**+TDREL180UH060NE36A*19.011.210.422,600217443204
      CK40[C,U]T-30A-**+TDREL280UH070E36A*19.011.510.422,400217443206
      CK40[C,U]T-30A-**+TDREL280UH070XE36A*19.011.510.422,400217443207
      CK40[C,U]T-30A-**+TDRML180UH045E36A*19.011.510.422,400217443209
      CK40[C,U]T-30A-**+TDRML180UH045XE36A*19.011.510.422,400217443211
      CK40[C,U]T-30B-**+TDREL280UH090E36B*19.011.710.422,400217443223
      CK40[C,U]T-30B-**+TDRSL280UH080NV48B*19.011.210.423,000217443241
      CK40[C,U]T-30B-**+TDRSL280UH090V48B*19.011.510.422,800217443243
      CK40[C,U]T-30B-**+TDRSL280UH090XV48B*19.011.510.422,800217443244
      CK40[C,U]T-30B-**+TDRSL297UH040NV36B*19.011.210.423,200217443245
      CK40[C,U]T-30B-**+TDRSLP99UH070XV36B*19.011.510.422,800217443247
      CK40[C,U]T-30B-**+TDREL297UH045XV36B*19.011.210.423,000217443250
      CK40[C,U]T-30B-**+TDREL297UH070XV36B*19.011.510.423,000217443251
      CK40[C,U]T-30A-**+TDREL180UH040NE36A*19.011.210.422,600217443407
      CK40HT-30B-**+TDR · cold climateSL280UH090V36B*19.011.09.422,600217443316
      CK40HT-30B-**+TDR · cold climateSL280UH090V48B*19.011.59.422,800217443317
      CK40HT-30B-**+TDR · cold climateSLP99UH070XV36B*19.011.09.422,800217443321
      CK40HT-30B-**+TDR · cold climateSL280UH090XV48B*19.011.59.422,800217443326
      CK40HT-30B-**+TDR · cold climateEL297UH070XV36B*19.011.29.422,800217443334
      CK40DT-30/36B-**+TDREL297DF045XV36B*19.011.09.219,100217443264
      CK40DT-30/36C-**+TDRSLP99DF090XV48C*19.011.29.219,500217443305
      CK40DT-30/36B-**+TDRML193DF045XE36B*19.011.09.019,500217443256
      CK40DT-30/36B-**+TDRSL280DF090V48B*19.011.29.019,700217443263
      CK40HT-30B-**+TDR · cold climateEL280UH090E36B*19.011.59.022,400217443270
      CK40HT-30B-**+TDR · cold climateSL297UH040NV36B*19.011.29.023,200217443318
      CK40[C,U]T-36B-**+TDR · cold climateML180UH070V36B*19.011.78.521,400217121571
      CK40[C,U]T-36B-**+TDR · cold climateML180UH070V48B*19.011.78.521,400217121572
      CBK47UHET-036-230- · cold climate-19.011.58.525,200217121562
      CK40[C,U]T-36B-**+TDR · cold climateML180UH090V48B*19.011.58.521,400217121574
      CBK47UHET-036-460- · cold climate-19.011.58.525,200217595417
      CK40[C,U]T-36C-**+TDR · cold climateML297UH110XV60C*19.011.58.522,000218732598
      CK40[C,U]T-30A-**+TDRML180UH070XE36A*18.511.510.422,600217443214
      CK40[C,U]T-30A-**+TDRSL280UH070XV36A*18.511.210.423,000217443217
      CK40[C,U]T-30A-**+TDRSL280UH070V36A*18.511.210.423,000217443216
      CK40[C,U]T-30B-**+TDRML180UH070E36B*18.511.510.422,600217443226
      CK40[C,U]T-30B-**+TDRML180UH070XE36B*18.511.510.422,600217443229
      CK40[C,U]T-30B-**+TDRSL297UH060NV36B*18.511.210.423,200217443246
      CK40[C,U]T-30B-**+TDREL297UH070XE36B*18.511.210.422,600217443248
      CK40[C,U]T-30B-**+TDRML180UH070V48B*18.511.710.222,600217443228
      CK40[C,U]T-30B-**+TDRML196UH030XE36B*18.511.210.222,800217443236
      CK40[C,U]T-30B-**+TDRML197UH030XE36B*18.511.210.223,000218745055
      CK40[C,U]T-30B-**+TDRML180UH070V36B*18.511.710.022,400217443227
      CK40HT-42C-**+TDR · cold climateSLP99UH090XV36C*18.511.29.622,600217443341
      CK40HT-42C-**+TDR · cold climateEL297UH090XV36C*18.511.29.622,600217443354
      CK40DT-30/36C-**+TDRSL280DF090V60C*18.511.59.219,300217443297
      CK40DT-30/36C-**+TDRSL280DF110V60C*18.511.59.219,300217443300
      CK40DT-30/36C-**+TDRSLP99DF110XV60C*18.511.29.219,500217443311
      CK40[C,U]T-36B-**+TDR · cold climateSL280UH080NV48B*18.511.29.022,200217117040
      CK40[C,U]T-36B-**+TDR · cold climateSL280UH090V36B*18.511.59.022,200217117041
      CK40[C,U]T-36B-**+TDR · cold climateSL280UH090V48B*18.511.29.022,200217117042
      CK40[C,U]T-36B-**+TDR · cold climateSL280UH090XV48B*18.511.29.022,200217117043
      CK40[C,U]T-36B-**+TDR · cold climateSL297UH040NV36B*18.511.09.022,600217117044
      CK40[C,U]T-36B-**+TDR · cold climateSLP99UH070XV36B*18.511.29.022,200217117046
      Yearly running cost in 10 large cities$778-$1,951

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

      Questions5
      What is the SEER2 rating of the Lennox EL21KLV-036-230A?
      The Lennox EL21KLV-036-230A is rated at up to 20.0 SEER2 and 11.7 EER2 for cooling and up to 10.4 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 299 certified matchups SEER2 ranges from 15.2-20.0.
      Is the Lennox EL21KLV-036-230A good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 25,400 BTU/h at 5°F with a COP of 2.48, so it is still 2.5 times as efficient as electric resistance heat at that temperature.
      How much does the Lennox EL21KLV-036-230A cost to run per year?
      At its rated efficiency it costs about $778-$1,951 a year in electricity in large U.S. cities, depending on climate and local rates - for example $941 in Phoenix and $1,616 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 Lennox EL21KLV-036-230A?
      ENERGY STAR lists 299 certified combinations for this outdoor unit. The highest-rated ones use CBK48MVT-036-230-, CBK45UHVT-042-230-, CK40[C,U]T-30B-**+TDR.
      What refrigerant does the Lennox EL21KLV-036-230A 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 $925/yrYou save $761/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 Lennox EL21KLV-036-230A
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $925
      Current system, per year
      $1,686
      You save per year
      $761
      Payback
      16.4 years
      Net after 10 years
      -$4,889

      Cooling $584Heating $340Electricity used: 5,779 kWhSaved vs. a minimum-efficiency heat pump: $364

      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 30, 2026. How we use the data.