HVAC Rated

9,000 BTU mini-split heat pump · O-HH Series

MRCOOL O-HH-09-HP-C-230C-O

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

Ranks #77 of 395 9,000 BTU mini-splits for cooling efficiency, and costs about $197 a year to run in a mixed climate like Atlanta.

SEER2
27.4 Cooling efficiency over a season
Excellent · beats 96%
HSPF2
12.5 Heating efficiency over a season
Excellent · beats 93%
EER2
15.4 Cooling efficiency on a 95°F day
Excellent · beats 93%
Heat at 5°F
11,500 BTU/h96% of its 47°F output
Below average · beats 22%

A good fit if…

  • You want low cooling bills - its SEER2 beats 96% of mini-splits.
  • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 11,500 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
BrandMRCOOL
Outdoor unit modelO-HH-09-HP-C-230C-O
SeriesO-HH 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 sinceOctober 25, 2024
Last certifiedMay 6, 2026
Cooling
SEER2Seasonal efficiency, higher is better27.4 (range 21.4-27.4)
EER2Efficiency at 95°F outdoors13.4-15.4
Cooling capacity9,000 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better12.1-12.5
Capacity at 47°F10,000-12,000 BTU/h
Capacity at 17°F9,600-12,000 BTU/h
Capacity at 5°F11,000-11,500 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater1.80-1.89
ENERGY STAR cold climateYes
Heating output as it gets colder96% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with O-09-HP-WMAH-230C-O at the standard test temperatures, in BTU/h:

Certified matchups3 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.
O-09-HP-WMAH-230C-O · cold climate27.415.412.511,500216032557
CASSETTE09HP-230C-O · cold climate22.614.012.111,000216032558
DUCT-09HP-230B-O · cold climate21.413.412.511,200216032559
Same unit, other model numbers1

These model numbers have exactly the same certified ratings and matchups as the MRCOOL O-HH-09-HP-C-230C-O: 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$155-$488

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

Questions6
What is the SEER2 rating of the MRCOOL O-HH-09-HP-C-230C-O?
The MRCOOL O-HH-09-HP-C-230C-O is rated at up to 27.4 SEER2 and 15.4 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 3 certified matchups SEER2 ranges from 21.4-27.4.
Is the MRCOOL O-HH-09-HP-C-230C-O good for cold climates?
Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 11,500 BTU/h at 5°F with a COP of 1.89, so it is still 1.9 times as efficient as electric resistance heat at that temperature.
How much does the MRCOOL O-HH-09-HP-C-230C-O cost to run per year?
At its rated efficiency it costs about $155-$488 a year in electricity in large U.S. cities, depending on climate and local rates - for example $202 in Phoenix and $415 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
Is the MRCOOL O-HH-09-HP-C-230C-O the same as the MRCOOL O-ES-09-HP-C-230C-O1?
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 MRCOOL O-HH-09-HP-C-230C-O?
ENERGY STAR lists 3 certified combinations for this outdoor unit. The highest-rated ones use O-09-HP-WMAH-230C-O, CASSETTE09HP-230C-O, DUCT-09HP-230B-O.
What refrigerant does the MRCOOL O-HH-09-HP-C-230C-O 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 $205/yrYou save $275/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 MRCOOL O-HH-09-HP-C-230C-O
3. What it replaces
4. Price replace the example with your quote
Heat pump, per year
$205
Current system, per year
$480
You save per year
$275
Payback
12.7 years
Net after 10 years
-$748

Cooling $116Heating $90Electricity used: 1,283 kWhSaved vs. a minimum-efficiency heat pump: $166

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 May 6, 2026. How we use the data.