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      9,000 BTU mini-split heat pump · BMS Series

      Bosch BMS500-AAS009-1CSXRD

      Excellent cooling and heating efficiency for a 9,000 BTU mini-split heat pump, and certified for cold climates.

      Ranks #144 of 395 9,000 BTU mini-splits for cooling efficiency, and costs about $201 a year to run in a mixed climate like Atlanta.

      SEER2
      25.8 Cooling efficiency over a season
      Excellent · beats 90%
      HSPF2
      12.5 Heating efficiency over a season
      Excellent · beats 93%
      EER2
      14.9 Cooling efficiency on a 95°F day
      Very good · beats 89%
      Heat at 5°F
      8,600 BTU/h80% of its 47°F output
      Excellent · beats 93%

      A good fit if…

      • You want low cooling bills - its SEER2 beats 90% of mini-splits.
      • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 8,600 BTU/h at 5°F.
      • It will heat most of the year - its HSPF2 beats 93% of mini-splits.
      • 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

      Specifications9,000 BTU, R-454B
      General
      BrandBosch
      Outdoor unit modelBMS500-AAS009-1CSXRD
      SeriesBMS Series
      TypeMini-split heat pump
      Nominal size9,000 BTU
      CompressorVariable-speed units run longer at low powerContinuously variable
      RefrigerantR-454B
      Connected (smart) capableNo
      On the market sinceMarch 18, 2024
      Last certifiedJanuary 14, 2026
      Cooling
      SEER2Seasonal efficiency, higher is better25.8 (range 19.5-25.8)
      EER2Efficiency at 95°F outdoors12.8-18.1
      Cooling capacity6,000-9,000 BTU/h
      Heating
      HSPF2Seasonal efficiency, higher is better11.0-12.5
      Capacity at 47°F6,000-11,000 BTU/h
      Capacity at 17°F7,900-8,900 BTU/h
      Capacity at 5°F8,000-8,600 BTU/h
      COP at 5°F2.0 = twice as efficient as a space heater2.17-2.40
      ENERGY STAR cold climateYes
      Heating output as it gets colder80% kept at 5°F

      Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with BMS500-AAU009-1AHWXD at the standard test temperatures, in BTU/h:

      Certified matchups5 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.
      BMS500-AAU009-1AHWXD BOSCH · cold climate25.814.912.58,000215223294
      BMS500-AAU006-1AHWXD BOSCH · cold climate25.018.112.58,300217656832
      BMS500-AAU009-1AHZXD BOSCH · cold climate22.114.411.88,000215223295
      BMS500-AAU009-1AHCXD BOSCH · cold climate21.614.311.38,300215223296
      BMS500-AAU009-1AHDXD BOSCH · cold climate19.512.811.08,600215223297
      Yearly running cost in 10 large cities$165-$492

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

      Questions5
      What is the SEER2 rating of the Bosch BMS500-AAS009-1CSXRD?
      The Bosch BMS500-AAS009-1CSXRD is rated at up to 25.8 SEER2 and 14.9 EER2 for cooling and up to 12.5 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 5 certified matchups SEER2 ranges from 19.5-25.8.
      Is the Bosch BMS500-AAS009-1CSXRD good for cold climates?
      Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 8,600 BTU/h at 5°F with a COP of 2.40, so it is still 2.4 times as efficient as electric resistance heat at that temperature.
      How much does the Bosch BMS500-AAS009-1CSXRD cost to run per year?
      At its rated efficiency it costs about $165-$492 a year in electricity in large U.S. cities, depending on climate and local rates - for example $210 in Phoenix and $417 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 Bosch BMS500-AAS009-1CSXRD?
      ENERGY STAR lists 5 certified combinations for this outdoor unit. The highest-rated ones use BOSCH BMS500-AAU009-1AHWXD, BOSCH BMS500-AAU006-1AHWXD, BOSCH BMS500-AAU009-1AHZXD.
      What refrigerant does the Bosch BMS500-AAS009-1CSXRD 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 $212/yrYou save $268/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 Bosch BMS500-AAS009-1CSXRD
      3. What it replaces
      4. Price replace the example with your quote
      Heat pump, per year
      $212
      Current system, per year
      $480
      You save per year
      $268
      Payback
      13.1 years
      Net after 10 years
      -$820

      Cooling $123Heating $90Electricity used: 1,327 kWhSaved vs. a minimum-efficiency heat pump: $158

      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 January 14, 2026. How we use the data.