What is the SEER2 rating of the Panasonic CU-HE18YAHK6?

The Panasonic CU-HE18YAHK6 is rated at up to 18.0 SEER2 and 12.4 EER2 for cooling and up to 9.5 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 3 certified matchups SEER2 ranges from 16.1-18.0.

Is the Panasonic CU-HE18YAHK6 good for cold climates?

Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 16,500 BTU/h at 5°F with a COP of 2.20, so it is still 2.2 times as efficient as electric resistance heat at that temperature.

How much does the Panasonic CU-HE18YAHK6 cost to run per year?

At its rated efficiency it costs about $470-$1,262 a year in electricity in large U.S. cities, depending on climate and local rates - for example $580 in Phoenix and $1,055 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.

Is the Panasonic CU-HE18YAHK6 the same as the ComfortStar CPH18CD(O)?

Yes, as far as the certified ratings go. ENERGY STAR lists 4 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 Panasonic CU-HE18YAHK6?

ENERGY STAR lists 3 certified combinations for this outdoor unit. The highest-rated ones use CS-HE18YAHK6, CS-HE24YAC6.

What refrigerant does the Panasonic CU-HE18YAHK6 use?

It uses R-410A. R-410A is being phased down under the EPA AIM Act, and new systems are moving to R-454B and R-32.

1.5-ton central heat pump · CU series

Panasonic CU-HE18YAHK6

Average cooling efficiency and very good heating efficiency for a 1.5-ton central heat pump, and certified for cold climates.

Ranks #63 of 170 1.5 ton central heat pumps for cooling efficiency, and costs about $527 a year to run in a mixed climate like Atlanta.

SEER2: 18.0 Cooling efficiency over a season
Average · beats 66%
HSPF2: 9.5 Heating efficiency over a season
Very good · beats 70%
EER2: 12.4 Cooling efficiency on a 95°F day
Very good · beats 76%
Heat at 5°F: 16,500 BTU/h87% of its 47°F output
Very good · beats 76%

A good fit if…

Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 16,500 BTU/h at 5°F.
It will heat most of the year - its HSPF2 beats 70% of central heat pumps.
You want steady temperatures and quiet running - the compressor varies its speed.

Think twice if…

You want the newest refrigerant - it uses R-410A, which is being phased down.

Calculate my running cost

Details

Specifications1.5 ton, R-410A

General
Brand	Panasonic
Also sold as	ComfortStar, KERR, Kepler
Outdoor unit model	CU-HE18YAHK6
Series	CU series
Type	Central heat pump
Nominal size	1.5 ton
CompressorVariable-speed units run longer at low power	Continuously variable
Refrigerant	R-410A
Connected (smart) capable	No
On the market since	August 1, 2023
Last certified	June 3, 2026
Cooling
SEER2Seasonal efficiency, higher is better	18.0 (range 16.1-18.0)
EER2Efficiency at 95°F outdoors	11.7-12.4
Cooling capacity	18,000 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better	9.3-9.5
Capacity at 47°F	19,000 BTU/h
Capacity at 17°F	13,500-14,700 BTU/h
Capacity at 5°F	15,000-16,500 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater	2.04-2.20
ENERGY STAR cold climate	Yes

Heating output as it gets colder87% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with CS-HE18YAHK6 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 unit	SEER2	EER2	HSPF2	Heat @5°F	AHRI ref.
CS-HE18YAHK6 · cold climate	18.0	12.4	9.3	16,500	212396492
CS-HE24YAC6 · cold climate	16.1	11.7	9.5	15,000	213082093
CS-HE24YAC6 · cold climate	16.1	11.7	9.5	15,000	213160450

Same unit, other model numbers3

These model numbers have exactly the same certified ratings and matchups as the Panasonic CU-HE18YAHK6: the same equipment under another brand, or a variant code for voltage, colour or market. Everything on this page applies to them.

ComfortStar CPH18CD(O)
KERR A-KCD18SA-1
Kepler AZPN/18WD

Yearly running cost in 10 large cities$470-$1,262

Phoenix, AZ$580/yr
Miami, FL$470/yr
Houston, TX$520/yr
Atlanta, GA$527/yr
Los Angeles, CA$514/yr
New York, NY$1,262/yr
Chicago, IL$1,025/yr
Denver, CO$852/yr
Seattle, WA$524/yr
Minneapolis, MN$1,055/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 Panasonic CU-HE18YAHK6?: The Panasonic CU-HE18YAHK6 is rated at up to 18.0 SEER2 and 12.4 EER2 for cooling and up to 9.5 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 3 certified matchups SEER2 ranges from 16.1-18.0.
Is the Panasonic CU-HE18YAHK6 good for cold climates?: Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 16,500 BTU/h at 5°F with a COP of 2.20, so it is still 2.2 times as efficient as electric resistance heat at that temperature.
How much does the Panasonic CU-HE18YAHK6 cost to run per year?: At its rated efficiency it costs about $470-$1,262 a year in electricity in large U.S. cities, depending on climate and local rates - for example $580 in Phoenix and $1,055 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
Is the Panasonic CU-HE18YAHK6 the same as the ComfortStar CPH18CD(O)?: Yes, as far as the certified ratings go. ENERGY STAR lists 4 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 Panasonic CU-HE18YAHK6?: ENERGY STAR lists 3 certified combinations for this outdoor unit. The highest-rated ones use CS-HE18YAHK6, CS-HE24YAC6.
What refrigerant does the Panasonic CU-HE18YAHK6 use?: It uses R-410A. R-410A is being phased down under the EPA AIM Act, and new systems are moving to R-454B and 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 $576/yrYou save $368/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 Panasonic CU-HE18YAHK6

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: $576
Current system, per year: $944
You save per year: $368
Payback: 19.0 years
Net after 10 years: -$3,315

Cooling $352Heating $224Electricity used: 3,600 kWhSaved vs. a minimum-efficiency heat pump: $151

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 1.5 ton models

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Midea 38MURAQ18AB3 · cold climate18.0 SEER2 · 9.5 HSPF2
Kinghome KU18UXO · cold climate18.0 SEER2 · 9.0 HSPF2
EMI MHSD118DACFC · cold climate18.0 SEER2 · 9.5 HSPF2
TOSOT TU18-R32WEDU · cold climate18.0 SEER2 · 9.0 HSPF2
Comfort-Aire A-VCD18SA-1 · cold climate18.0 SEER2 · 9.5 HSPF2
TOSOT TUD18-12W2/NHE-D(U) · cold climate18.0 SEER2 · 9.0 HSPF2

See all 170 1.5 ton central heat pumps, ranked

Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of June 3, 2026. How we use the data.