What is the SEER2 rating of the Mainline ML12HP230CALH-O?

The Mainline ML12HP230CALH-O is rated at up to 29.4 SEER2 and 14.2 EER2 for cooling and up to 12.7 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.

Is the Mainline ML12HP230CALH-O good for cold climates?

Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 13,500 BTU/h at 5°F with a COP of 2.00, so it is still 2.0 times as efficient as electric resistance heat at that temperature.

How much does the Mainline ML12HP230CALH-O cost to run per year?

At its rated efficiency it costs about $193-$581 a year in electricity in large U.S. cities, depending on climate and local rates - for example $247 in Phoenix and $492 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.

Is the Mainline ML12HP230CALH-O the same as the Comfort-Aire A-ZHP12SA-1?

Yes, as far as the certified ratings go. ENERGY STAR lists 3 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 Mainline ML12HP230CALH-O?

ENERGY STAR lists 2 certified combinations for this outdoor unit. The highest-rated one uses MAINLINE ML12HP230CALH-I.

12,000 BTU mini-split heat pump · ML Series

Mainline ML12HP230CALH-O

Excellent cooling and heating efficiency for a 12,000 BTU mini-split heat pump, and certified for cold climates.

Ranks #14 of 394 12,000 BTU mini-splits for cooling efficiency, and costs about $237 a year to run in a mixed climate like Atlanta.

SEER2: 29.4 Cooling efficiency over a season
Excellent · beats 98%
HSPF2: 12.7 Heating efficiency over a season
Excellent · beats 94%
EER2: 14.2 Cooling efficiency on a 95°F day
Very good · beats 86%
Heat at 5°F: 13,500 BTU/h113% of its 47°F output
Average · beats 48%

A good fit if…

You want low cooling bills - its SEER2 beats 98% of mini-splits.
Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 13,500 BTU/h at 5°F.
It will heat most of the year - its HSPF2 beats 94% 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

Specifications12,000 BTU, R-454B

General
Brand	Mainline
Also sold as	Comfort-Aire, KERR, Kerr Kapstone
Outdoor unit model	ML12HP230CALH-O
Series	ML Series
Type	Mini-split heat pump
Nominal size	12,000 BTU
CompressorVariable-speed units run longer at low power	Continuously variable
Refrigerant	R-454B
Connected (smart) capable	No
On the market since	May 20, 2024
Last certified	August 11, 2026
Cooling
SEER2Seasonal efficiency, higher is better	29.4 (range 29.4)
EER2Efficiency at 95°F outdoors	14.2
Cooling capacity	12,000 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better	12.7
Capacity at 47°F	12,000 BTU/h
Capacity at 17°F	11,000 BTU/h
Capacity at 5°F	13,500 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater	2.00
ENERGY STAR cold climate	Yes

Heating output as it gets colder113% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with ML12HP230CALH-I at the standard test temperatures, in BTU/h:

Certified matchups2 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 unit	SEER2	EER2	HSPF2	Heat @5°F	AHRI ref.
ML12HP230CALH-I MAINLINE · cold climate	29.4	14.2	12.7	13,500	217607259
ML12HP230CALH-I MAINLINE · cold climate	29.4	14.2	12.7	13,500	215864346

Same unit, other model numbers2

These model numbers have exactly the same certified ratings and matchups as the Mainline ML12HP230CALH-O: the same equipment under another brand, or a variant code for voltage, colour or market. Everything on this page applies to them.

Comfort-Aire A-ZHP12SA-1
KERR A-KZP12SA-1

Yearly running cost in 10 large cities$193-$581

Phoenix, AZ$247/yr
Miami, FL$193/yr
Houston, TX$222/yr
Atlanta, GA$237/yr
Los Angeles, CA$233/yr
New York, NY$581/yr
Chicago, IL$474/yr
Denver, CO$397/yr
Seattle, WA$246/yr
Minneapolis, MN$492/yr

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

Questions6

What is the SEER2 rating of the Mainline ML12HP230CALH-O?: The Mainline ML12HP230CALH-O is rated at up to 29.4 SEER2 and 14.2 EER2 for cooling and up to 12.7 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
Is the Mainline ML12HP230CALH-O good for cold climates?: Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 13,500 BTU/h at 5°F with a COP of 2.00, so it is still 2.0 times as efficient as electric resistance heat at that temperature.
How much does the Mainline ML12HP230CALH-O cost to run per year?: At its rated efficiency it costs about $193-$581 a year in electricity in large U.S. cities, depending on climate and local rates - for example $247 in Phoenix and $492 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
Is the Mainline ML12HP230CALH-O the same as the Comfort-Aire A-ZHP12SA-1?: Yes, as far as the certified ratings go. ENERGY STAR lists 3 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 Mainline ML12HP230CALH-O?: ENERGY STAR lists 2 certified combinations for this outdoor unit. The highest-rated one uses MAINLINE ML12HP230CALH-I.
What refrigerant does the Mainline ML12HP230CALH-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 $250/yrYou save $369/yrSee details ↓

1. Where you live

StateCityElectricity ¢ per kWh

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.

Cooling hours full-load hours per yearHeating hours full-load hours per year

2. The heat pump Mainline ML12HP230CALH-O

Find a model (fills in the ratings below)

SEER2 cooling efficiencyHSPF2 heating efficiencyCooling capacity BTU/hHeating capacity BTU/h

3. What it replaces

Current heatingFurnace efficiency (AFUE %)Gas price, $/thermCurrent coolingOld AC rating SEER2 (10 ≈ 15+ years old)

4. Price replace the example with your quote

Installed price, $Rebates and incentives, $ utility, state

Heat pump, per year: $250
Current system, per year: $619
You save per year: $369
Payback: 12.2 years
Net after 10 years: -$808

Cooling $144Heating $106Electricity used: 1,559 kWhSaved vs. a minimum-efficiency heat pump: $225

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 12,000 BTU models

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Fujitsu AOUG12LZAS1 · cold climate29.4 SEER2 · 12.9 HSPF2
Arcoaire D5CPRAH12AAK · cold climate28.0 SEER2 · 12.7 HSPF2
TOSOT TWH12AD32AO · cold climate29.5 SEER2 · 10.0 HSPF2
Deye DWA4-12K28.0 SEER2 · 9.7 HSPF2
TOSOT TW12WH29D6DO · cold climate29.5 SEER2 · 10.0 HSPF2
Goodman MSH123G26MCAA · cold climate27.5 SEER2 · 14.5 HSPF2

See all 394 12,000 BTU mini-splits, ranked

Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of August 11, 2026. How we use the data.