What is the SEER2 rating of the Napoleon NH25-18H-O?

The Napoleon NH25-18H-O is rated at up to 19.4 SEER2 and 12.5 EER2 for cooling and up to 10.4 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 2 certified matchups SEER2 ranges from 18.9-19.4.

Is the Napoleon NH25-18H-O good for cold climates?

Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 23,400 BTU/h at 5°F with a COP of 1.90, so it is still 1.9 times as efficient as electric resistance heat at that temperature.

How much does the Napoleon NH25-18H-O cost to run per year?

At its rated efficiency it costs about $523-$1,417 a year in electricity in large U.S. cities, depending on climate and local rates - for example $648 in Phoenix and $1,186 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 Napoleon NH25-18H-O?

ENERGY STAR lists 2 certified combinations for this outdoor unit. The highest-rated ones use NAPOLEON NH25-18F-I, NAPOLEON NH25-24F-I.

What refrigerant does the Napoleon NH25-18H-O 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.

24,000 BTU mini-split heat pump · NH series

Napoleon NH25-18H-O

Below average cooling efficiency and average heating efficiency for a 24,000 BTU mini-split heat pump, and certified for cold climates.

Ranks #369 of 430 24,000 BTU mini-splits for cooling efficiency, and costs about $591 a year to run in a mixed climate like Atlanta.

SEER2: 19.4 Cooling efficiency over a season
Below average · beats 11%
HSPF2: 10.4 Heating efficiency over a season
Average · beats 57%
EER2: 12.5 Cooling efficiency on a 95°F day
Average · beats 44%
Heat at 5°F: 23,400 BTU/h91% of its 47°F output
Below average · beats 27%

A good fit if…

Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 23,400 BTU/h at 5°F.
You want steady temperatures and quiet running - the compressor varies its speed.

Think twice if…

Cooling cost matters most - its SEER2 is below average for mini-splits.
You want the newest refrigerant - it uses R-410A, which is being phased down.

Calculate my running cost

Details

Specifications24,000 BTU, R-410A

General
Brand	Napoleon
Outdoor unit model	NH25-18H-O
Series	NH series
Type	Mini-split heat pump
Nominal size	24,000 BTU
CompressorVariable-speed units run longer at low power	Continuously variable
Refrigerant	R-410A
Connected (smart) capable	No
On the market since	February 2, 2021
Last certified	June 25, 2026
Cooling
SEER2Seasonal efficiency, higher is better	19.4 (range 18.9-19.4)
EER2Efficiency at 95°F outdoors	11.7-12.5
Cooling capacity	17,000-21,600 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better	10.0-10.4
Capacity at 47°F	18,000-23,400 BTU/h
Capacity at 17°F	10,900-19,400 BTU/h
Capacity at 5°F	16,400-23,400 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater	1.89-1.90
ENERGY STAR cold climate	Yes

Heating output as it gets colder91% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with NH25-18F-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.
NH25-18F-I NAPOLEON	19.4	12.5	10.0	16,400	206597271
NH25-24F-I NAPOLEON · cold climate	18.9	11.7	10.4	23,400	206597272

Yearly running cost in 10 large cities$523-$1,417

Phoenix, AZ$648/yr
Miami, FL$523/yr
Houston, TX$581/yr
Atlanta, GA$591/yr
Los Angeles, CA$576/yr
New York, NY$1,417/yr
Chicago, IL$1,151/yr
Denver, CO$958/yr
Seattle, WA$589/yr
Minneapolis, MN$1,186/yr

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

Questions5

What is the SEER2 rating of the Napoleon NH25-18H-O?: The Napoleon NH25-18H-O is rated at up to 19.4 SEER2 and 12.5 EER2 for cooling and up to 10.4 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with; across its 2 certified matchups SEER2 ranges from 18.9-19.4.
Is the Napoleon NH25-18H-O good for cold climates?: Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 23,400 BTU/h at 5°F with a COP of 1.90, so it is still 1.9 times as efficient as electric resistance heat at that temperature.
How much does the Napoleon NH25-18H-O cost to run per year?: At its rated efficiency it costs about $523-$1,417 a year in electricity in large U.S. cities, depending on climate and local rates - for example $648 in Phoenix and $1,186 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 Napoleon NH25-18H-O?: ENERGY STAR lists 2 certified combinations for this outdoor unit. The highest-rated ones use NAPOLEON NH25-18F-I, NAPOLEON NH25-24F-I.
What refrigerant does the Napoleon NH25-18H-O 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 $644/yrYou save $499/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 Napoleon NH25-18H-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: $644
Current system, per year: $1,143
You save per year: $499
Payback: 16.0 years
Net after 10 years: -$3,007

Cooling $392Heating $252Electricity used: 4,024 kWhSaved vs. a minimum-efficiency heat pump: $237

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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Trane / Mitsubishi Electric SUZ-KA30NA19.4 SEER2 · 11.7 HSPF2
Goodman MSH243E23MCAA · cold climate19.2 SEER2 · 10.5 HSPF2
GE Appliances 1G24AD2BE · cold climate19.5 SEER2 · 9.5 HSPF2
MOOVAIR DM24HOS25230E3A · cold climate19.2 SEER2 · 10.5 HSPF2
Haier 3U24EH2HD · cold climate19.5 SEER2 · 10.2 HSPF2
PerfectAire 1KARDA24SZO20.5 · cold climate19.2 SEER2 · 10.5 HSPF2

See all 430 24,000 BTU mini-splits, ranked

Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of June 25, 2026. How we use the data.