What is the SEER2 rating of the Ameristar M4THM1942A15N?

The Ameristar M4THM1942A15N is rated at up to 19.0 SEER2 and 12.0 EER2 for cooling and up to 10.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.

Is the Ameristar M4THM1942A15N good for cold climates?

Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 32,400 BTU/h at 5°F with a COP of 1.92, so it is still 1.9 times as efficient as electric resistance heat at that temperature.

How much does the Ameristar M4THM1942A15N cost to run per year?

At its rated efficiency it costs about $892-$2,499 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,115 in Phoenix and $2,100 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.

What refrigerant does the Ameristar M4THM1942A15N 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.

36,000 BTU mini-split heat pump · N-Series

Ameristar M4THM1942A15N

Below average cooling efficiency and average heating efficiency for a 36,000 BTU mini-split heat pump, and certified for cold climates.

Ranks #189 of 205 36,000 BTU mini-splits for cooling efficiency, and costs about $1,034 a year to run in a mixed climate like Atlanta.

SEER2: 19.0 Cooling efficiency over a season
Below average · beats 9%
HSPF2: 10.0 Heating efficiency over a season
Average · beats 43%
EER2: 12.0 Cooling efficiency on a 95°F day
Below average · beats 25%
Heat at 5°F: 32,400 BTU/h81% of its 47°F output
Below average · beats 32%

A good fit if…

Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 32,400 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

Specifications36,000 BTU, R-410A

General
Brand	Ameristar
Also sold as	RunTru
Outdoor unit model	M4THM1942A15N
Series	N-Series
Type	Mini-split heat pump
Nominal size	36,000 BTU
CompressorVariable-speed units run longer at low power	Continuously variable
Refrigerant	R-410A
Connected (smart) capable	No
On the market since	January 1, 2023
Last certified	June 13, 2026
Cooling
SEER2Seasonal efficiency, higher is better	19.0 (range 19.0)
EER2Efficiency at 95°F outdoors	12.0
Cooling capacity	36,000 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better	10.0
Capacity at 47°F	40,000 BTU/h
Capacity at 17°F	35,600 BTU/h
Capacity at 5°F	32,400 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater	1.92
ENERGY STAR cold climate	Yes

Heating output as it gets colder81% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its best matchup 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.
- · cold climate	19.0	12.0	10.0	32,400	210488263
- RUNTRU · cold climate	19.0	12.0	10.0	32,400	210488278

Yearly running cost in 10 large cities$892-$2,499

Phoenix, AZ$1,115/yr
Miami, FL$892/yr
Houston, TX$1,000/yr
Atlanta, GA$1,034/yr
Los Angeles, CA$1,011/yr
New York, NY$2,499/yr
Chicago, IL$2,034/yr
Denver, CO$1,695/yr
Seattle, WA$1,045/yr
Minneapolis, MN$2,100/yr

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

Questions4

What is the SEER2 rating of the Ameristar M4THM1942A15N?: The Ameristar M4THM1942A15N is rated at up to 19.0 SEER2 and 12.0 EER2 for cooling and up to 10.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
Is the Ameristar M4THM1942A15N good for cold climates?: Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 32,400 BTU/h at 5°F with a COP of 1.92, so it is still 1.9 times as efficient as electric resistance heat at that temperature.
How much does the Ameristar M4THM1942A15N cost to run per year?: At its rated efficiency it costs about $892-$2,499 a year in electricity in large U.S. cities, depending on climate and local rates - for example $1,115 in Phoenix and $2,100 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
What refrigerant does the Ameristar M4THM1942A15N 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 $1,115/yrYou save $807/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 Ameristar M4THM1942A15N

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: $1,115
Current system, per year: $1,922
You save per year: $807
Payback: 16.7 years
Net after 10 years: -$5,432

Cooling $667Heating $448Electricity used: 6,968 kWhSaved vs. a minimum-efficiency heat pump: $369

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 36,000 BTU models

Haier 4U36EH2HD · cold climate19.0 SEER2 · 9.5 HSPF2
Midea MDV-H36DVN1-(D)19.2 SEER2 · 9.2 HSPF2
ComfortStar C32-MZ-4 · cold climate19.0 SEER2 · 9.0 HSPF2
Carrier 38VMB036HDS3-119.2 SEER2 · 9.2 HSPF2
Arcoaire D5CMTAH36EAK · cold climate18.8 SEER2 · 8.5 HSPF2
Mitsubishi Electric MXZ-5D36NL19.2 SEER2 · 9.3 HSPF2
Carrier 37MTRAQ36EA3 · cold climate18.8 SEER2 · 8.5 HSPF2
Lennox VPC036H4M-3PD19.2 SEER2 · 9.5 HSPF2

See all 205 36,000 BTU mini-splits, ranked

Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of June 13, 2026. How we use the data.