HVAC Rated

15,000 BTU mini-split heat pump · M-Series

Mitsubishi Electric MUZ-FX15NLHZ

Excellent cooling efficiency and very good heating efficiency for a 15,000 BTU mini-split heat pump, and certified for cold climates.

Ranks #5 of 62 15,000 BTU mini-splits for cooling efficiency, and costs about $362 a year to run in a mixed climate like Atlanta.

SEER2
25.9 Cooling efficiency over a season
Excellent · beats 90%
HSPF2
11.0 Heating efficiency over a season
Very good · beats 75%
EER2
14.7 Cooling efficiency on a 95°F day
Very good · beats 89%
Heat at 5°F
22,200 BTU/h135% of its 47°F output
Average · beats 61%

A good fit if…

  • You want low cooling bills - its SEER2 beats 90% of mini-splits.
  • Your winters get properly cold - it is ENERGY STAR cold-climate certified, with 22,200 BTU/h at 5°F.
  • It will heat most of the year - its HSPF2 beats 75% 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

Specifications15,000 BTU, R-454B
General
BrandMitsubishi Electric
Outdoor unit modelMUZ-FX15NLHZ
SeriesM-Series
TypeMini-split heat pump
Nominal size15,000 BTU
CompressorVariable-speed units run longer at low powerContinuously variable
RefrigerantR-454B
Connected (smart) capableNo
On the market sinceJanuary 1, 2025
Last certifiedSeptember 1, 2026
Cooling
SEER2Seasonal efficiency, higher is better25.9 (range 25.9)
EER2Efficiency at 95°F outdoors14.7
Cooling capacity15,000 BTU/h
Heating
HSPF2Seasonal efficiency, higher is better11.0
Capacity at 47°F16,500 BTU/h
Capacity at 17°F10,600 BTU/h
Capacity at 5°F22,200 BTU/h
COP at 5°F2.0 = twice as efficient as a space heater2.06
ENERGY STAR cold climateYes
Heating output as it gets colder135% kept at 5°F

Every heat pump delivers less heat as the outdoor temperature drops. Certified output of its matchup with MSZ-FX15NL at the standard test temperatures, in BTU/h:

Certified matchups1 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 unitSEER2EER2HSPF2Heat @5°FAHRI ref.
MSZ-FX15NL · cold climate25.914.711.022,200215611127
Same unit, other model numbers1

These model numbers have exactly the same certified ratings and matchups as the Mitsubishi Electric MUZ-FX15NLHZ: the same equipment under another brand, or a variant code for voltage, colour or market. Everything on this page applies to them.

Yearly running cost in 10 large cities$275-$905

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-FX15NLHZ?
The Mitsubishi Electric MUZ-FX15NLHZ is rated at up to 25.9 SEER2 and 14.7 EER2 for cooling and up to 11.0 HSPF2 for heating. The exact figure depends on the indoor unit it is paired with.
Is the Mitsubishi Electric MUZ-FX15NLHZ good for cold climates?
Yes. At least one certified matchup meets the ENERGY STAR cold-climate criteria, delivering up to 22,200 BTU/h at 5°F with a COP of 2.06, so it is still 2.1 times as efficient as electric resistance heat at that temperature.
How much does the Mitsubishi Electric MUZ-FX15NLHZ cost to run per year?
At its rated efficiency it costs about $275-$905 a year in electricity in large U.S. cities, depending on climate and local rates - for example $362 in Phoenix and $775 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-FX15NLHZ the same as the Mitsubishi Electric MUZ-FX15NLHZ2?
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-FX15NLHZ?
ENERGY STAR lists 1 certified combination for this outdoor unit. The highest-rated one uses MSZ-FX15NL.
What refrigerant does the Mitsubishi Electric MUZ-FX15NLHZ 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 $372/yrYou save $426/yrSee details ↓
1. Where you live
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.

2. The heat pump Mitsubishi Electric MUZ-FX15NLHZ
3. What it replaces
4. Price replace the example with your quote
Heat pump, per year
$372
Current system, per year
$798
You save per year
$426
Payback
12.9 years
Net after 10 years
-$1,239

Cooling $204Heating $168Electricity used: 2,324 kWhSaved vs. a minimum-efficiency heat pump: $244

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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Source: ENERGY STAR Certified Heat Pumps (U.S. EPA), certification of September 1, 2026. How we use the data.