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      9,000 BTU mini-split heat pump · WindFree - Standard (RAC)

      Lennox MWHD009S6-1P

      Very good cooling efficiency and below average heating efficiency for a 9,000 BTU mini-split heat pump, but not rated for cold climates.

      Ranks #183 of 395 9,000 BTU mini-splits for cooling efficiency, and costs about $273 a year to run in a mixed climate like Atlanta.

      SEER2
      25.0 Cooling efficiency over a season
      Very good · beats 83%
      HSPF2
      9.0 Heating efficiency over a season
      Below average · beats 10%
      EER2
      15.0 Cooling efficiency on a 95°F day
      Excellent · beats 91%
      Heat at 5°F
      7,500 BTU/h68% of its 47°F output
      Below average · beats 31%

      A good fit if…

      • You want low cooling bills - its SEER2 beats 83% of mini-splits.
      • You want steady temperatures and quiet running - the compressor varies its speed.

      Think twice if…

      • You often see nights below 0°F - it is not cold-climate certified.
      • You mainly need heat - its HSPF2 is below average for mini-splits.

      Calculate my running cost

      Details

      Specifications9,000 BTU, R-32
      General
      BrandLennox
      Outdoor unit modelMWHD009S6-1P
      SeriesWindFree - Standard (RAC)
      TypeMini-split heat pump
      Nominal size9,000 BTU
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-32
      Connected (smart) capableNo
      On the market sinceJuly 5, 2024
      Last certifiedApril 17, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better25.0 (range 25.0)
      EER2Efficiency at 95°F outdoors15.0
      Cooling capacity9,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better9.0
      Capacity at 47°F11,000 BTU/h
      Capacity at 17°F10,000 BTU/h
      Capacity at 5°F7,500 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater1.91
      ENERGY STAR cold climateNo
      Heating output as it gets colder68% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with MWHD009S6S-1P 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.
      MWHD009S6S-1P LENNOX25.015.09.07,500215810017
      Same unit, other model numbers1

      These model numbers have exactly the same certified ratings and matchups as the Lennox MWHD009S6-1P: 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$173-$711

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

      Questions6
      What is the SEER2 rating of the Lennox MWHD009S6-1P?
      The Lennox MWHD009S6-1P is rated at up to 25.0 SEER2 and 15.0 EER2 for cooling and up to 9.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
      Is the Lennox MWHD009S6-1P 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 9,000 BTU model.
      How much does the Lennox MWHD009S6-1P cost to run per year?
      At its rated efficiency it costs about $173-$711 a year in electricity in large U.S. cities, depending on climate and local rates - for example $248 in Phoenix and $620 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
      Is the Lennox MWHD009S6-1P the same as the Lennox MWHD009S6S-1P?
      Yes, as far as the certified ratings go. ENERGY STAR lists both 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.
      Which indoor units work with the Lennox MWHD009S6-1P?
      ENERGY STAR lists 1 certified combination for this outdoor unit. The highest-rated one uses LENNOX MWHD009S6S-1P.
      What refrigerant does the Lennox MWHD009S6-1P use?
      It uses 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 $264/yrYou save $233/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 MWHD009S6-1P
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $264
      Current system, per year
      $497
      You save per year
      $233
      Payback
      15.0 years
      Net after 10 years
      -$1,168

      Cooling $127Heating $137Electricity used: 1,648 kWhSaved vs. a minimum-efficiency heat pump: $122

      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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      See all 395 9,000 BTU mini-splits, ranked

      Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of April 17, 2026. How we use the data.