What is the SEER2 rating of the Mitsubishi Electric MUZ-FS09NA?

The Mitsubishi Electric MUZ-FS09NA is rated at up to 29.8 SEER2 and 16.1 EER2 for cooling and up to 10.9 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.

Is the Mitsubishi Electric MUZ-FS09NA good for cold climates?

Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 11,300 BTU/h at 5°F with a COP of 2.40, so it is still 2.4 times as efficient as electric resistance heat at that temperature.

How much does the Mitsubishi Electric MUZ-FS09NA cost to run per year?

At its rated efficiency it costs about $144-$522 a year in electricity in large U.S. cities, depending on climate and local rates - for example $197 in Phoenix and $451 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.

Is the Mitsubishi Electric MUZ-FS09NA the same as the Trane / Mitsubishi Electric NTXSPH09B112A?

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 Mitsubishi Electric MUZ-FS09NA?

ENERGY STAR lists 3 certified combinations for this outdoor unit. The highest-rated ones use MSZ-FS09NA, American Standard / Mitsubishi Electric NAXWPH09B112A, Trane / Mitsubishi Electric NTXWPH09B112A.

What refrigerant does the Mitsubishi Electric MUZ-FS09NA 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.

9,000 BTU mini-split heat pump · M-Series

Mitsubishi Electric MUZ-FS09NA

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

Ranks #21 of 395 9,000 BTU mini-splits for cooling efficiency, and costs about $205 a year to run in a mixed climate like Atlanta.

SEER2: 29.8 Cooling efficiency over a season
Excellent · beats 98%
HSPF2: 10.9 Heating efficiency over a season
Very good · beats 72%
EER2: 16.1 Cooling efficiency on a 95°F day
Excellent · beats 96%
Heat at 5°F: 11,300 BTU/h118% of its 47°F output
Excellent · beats 93%

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 11,300 BTU/h at 5°F.
It will heat most of the year - its HSPF2 beats 72% of mini-splits.
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

Specifications9,000 BTU, R-410A

General
Brand	Mitsubishi Electric
Also sold as	American Standard / Mitsubishi Electric, Trane / Mitsubishi Electric
Outdoor unit model	MUZ-FS09NA
Series	M-Series
Type	Mini-split heat pump
Nominal size	9,000 BTU
CompressorVariable-speed units run longer at low power	Continuously variable
Refrigerant	R-410A
Connected (smart) capable	No
On the market since	December 1, 2022
Last certified	March 13, 2025
Cooling
SEER2Seasonal efficiency, higher is better	29.8 (range 29.8)
EER2Efficiency at 95°F outdoors	16.1
Cooling capacity	9,000 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better	10.9
Capacity at 47°F	9,600 BTU/h
Capacity at 17°F	5,900 BTU/h
Capacity at 5°F	11,300 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater	2.40
ENERGY STAR cold climate	Yes

Heating output as it gets colder118% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with MSZ-FS09NA 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.
MSZ-FS09NA · cold climate	29.8	16.1	10.9	11,300	209832201
NAXWPH09B112A American Standard / Mitsubishi Electric · cold climate	29.8	16.1	10.9	11,300	209832984
NTXWPH09B112A Trane / Mitsubishi Electric · cold climate	29.8	16.1	10.9	11,300	209832985

Same unit, other model numbers1

These model numbers have exactly the same certified ratings and matchups as the Mitsubishi Electric MUZ-FS09NA: the same equipment under another brand, or a variant code for voltage, colour or market. Everything on this page applies to them.

Trane / Mitsubishi Electric NTXSPH09B112A

Yearly running cost in 10 large cities$144-$522

Phoenix, AZ$197/yr
Miami, FL$144/yr
Houston, TX$177/yr
Atlanta, GA$205/yr
Los Angeles, CA$206/yr
New York, NY$522/yr
Chicago, IL$430/yr
Denver, CO$363/yr
Seattle, WA$227/yr
Minneapolis, MN$451/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 Mitsubishi Electric MUZ-FS09NA?: The Mitsubishi Electric MUZ-FS09NA is rated at up to 29.8 SEER2 and 16.1 EER2 for cooling and up to 10.9 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
Is the Mitsubishi Electric MUZ-FS09NA good for cold climates?: Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 11,300 BTU/h at 5°F with a COP of 2.40, so it is still 2.4 times as efficient as electric resistance heat at that temperature.
How much does the Mitsubishi Electric MUZ-FS09NA cost to run per year?: At its rated efficiency it costs about $144-$522 a year in electricity in large U.S. cities, depending on climate and local rates - for example $197 in Phoenix and $451 in Minneapolis. The calculator on this page works it out for your city and compares it with your current system.
Is the Mitsubishi Electric MUZ-FS09NA the same as the Trane / Mitsubishi Electric NTXSPH09B112A?: 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 Mitsubishi Electric MUZ-FS09NA?: ENERGY STAR lists 3 certified combinations for this outdoor unit. The highest-rated ones use MSZ-FS09NA, American Standard / Mitsubishi Electric NAXWPH09B112A, Trane / Mitsubishi Electric NTXWPH09B112A.
What refrigerant does the Mitsubishi Electric MUZ-FS09NA 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 $205/yrYou save $269/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 Mitsubishi Electric MUZ-FS09NA

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: $205
Current system, per year: $474
You save per year: $269
Payback: 13.0 years
Net after 10 years: -$811

Cooling $106Heating $99Electricity used: 1,281 kWhSaved vs. a minimum-efficiency heat pump: $160

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 9,000 BTU models

American Standard / Mitsubishi Electric NAXSPH09B112A · cold climate29.8 SEER2 · 10.9 HSPF2
American Standard / Mitsubishi Electric NAXSPB09B112A · cold climate29.8 SEER2 · 10.0 HSPF2
TOSOT TWH09AD32AO · cold climate30.0 SEER2 · 11.2 HSPF2
TOSOT TW09WH29D6DO · cold climate30.0 SEER2 · 11.2 HSPF2
TOSOT TW09HAY32A1DO · cold climate30.0 SEER2 · 11.2 HSPF2
MDV MOX430-09HFN1-MZG5W · cold climate29.0 SEER2 · 15.0 HSPF2
Ouellet OARX-H09A-O · cold climate30.0 SEER2 · 11.2 HSPF2
Goodman MSH093G26MCAA · cold climate29.0 SEER2 · 14.0 HSPF2

See all 395 9,000 BTU mini-splits, ranked

Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of March 13, 2025. How we use the data.