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Mitsubishi Electric / M-Series HM

Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA)

Model data is drawn from manufacturer, retailer, and certification sources. Missing specifications remain marked as not published.

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Data completeness: 87%
Last verified
Jul 23, 2026

SplitAtlas score

7.7 / 10

Methodology
Cooling efficiency7.5
Heating efficiency39.9
Cold-weather performance46.1
Noise100.0
Warranty5.0
Feature set0.0
Documentation & parts50.0

Not evaluated

  • Installation accessibility — not applicable (professional install)N/A

    professional install - DIY-accessibility not applicable

  • Price-to-value — not evaluatedN/A

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Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA) review summary

The M-Series HM 12k is an obsolete (Production Stopped) R-410A value unit at 1 ton: SEER2 20, EER2 9.9, HSPF2 10, with 12,200 BTU of heat at 47F. Like the rest of the HM line it has been succeeded by the current R-454B HX 12k.

Rated cooling

12,000BTU/hVerified - AHRI directory

Rated heating

12,200BTU/hVerified - AHRI directory

Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA) best-fit use cases

Owners of an existing HM 12k - new buyers should choose the current HX 12k.

Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA) specifications

Manufacturer
Mitsubishi Electric
Brand
Mitsubishi Electric
Product line
M-Series HM
Model number
MSZ-HM12NA-U1 indoor / MUZ-HM12NA-U1 outdoor
Indoor unit model
MSZ-HM12NA-U1
Outdoor unit model
MUZ-HM12NA-U1
Number of zones
1
Max indoor units
not published
Rated cooling capacity
12,000 BTU/hVerified - AHRI directory
Rated heating capacity
12,200 BTU/hVerified - AHRI directory
Voltage
208/230VVerified - manufacturer product page
MCA
9 AVerified - manufacturer technical document
Maximum fuse or breaker size
15 AVerified - manufacturer technical document
Breaker needed
not published
SEER2
20 SEER2Verified - AHRI directory
EER2
9.9 EER2Verified - AHRI directory
HSPF2 (Region 4)
10 HSPF2Verified - AHRI directory
HSPF2 (Region 5)
not published
COP
not published
COP at 47F
3.61 COPVerified - manufacturer technical document
COP at 5F
not published
Minimum outdoor heating temperature
not published
Minimum outdoor cooling temperature
not published
Maximum outdoor temperature
not published
Indoor noise range
cooling 45-37-30-22; heating 43-37-30-22Verified - manufacturer technical document
Outdoor noise rating
51 dBAVerified - manufacturer technical document
Indoor weight
not published
Outdoor weight
73 lbVerified - manufacturer technical document
Refrigerant
R-410AVerified - AHRI directory
Refrigerant charge
not published
Manufacturer coverage
not published
Line-set size
1/4 in liquid / 3/8 in suction
Included line-set length
Mitsubishi submittals publish line-size and maximum/precharged piping data; the installer supplies the line set.
Maximum line-set length
65 ftVerified - manufacturer technical document
Max line set per indoor
not published
Maximum elevation difference
40 ftVerified - manufacturer technical document
Max height between indoor units
not published
Wi-Fi support
supportedVerified - manufacturer technical document
Energy Star status
not_certifiedVerified - AHRI directory
AHRI certification number
202680601Verified - AHRI directory
Warranty
5 years parts / 7 years compressor. Standard residential M-Series warranty is 5 years parts and 7 years compressor from installation by a licensed HVAC contractor. Enhanced residential terms are 10 years parts and compressor for an owner-occupied residence registered within 90 days of installation, and 12 years parts and compressor when installed in an owner-occupied residence by a Diamond Contractor and registered by that Diamond Contractor within 90 days.
DIY installation status
Professional install
Retail price
HVACDirect exact model search returned 403 and no exact product page with visible price was retrieved on 2026-07-23.
Installation type
Professional install
Available retailers
not published
Manual links
AHRI certificate 202680601, AHRI public detail 202680601, ENERGY STAR exact row for AHRI 202680601, M-Series HM Mitsubishi Comfort product page, M-Series HM Mitsubishi Comfort product page, MitsubishiPro product record MUZ-HM12NA-U1, HVACDirect exact search for MSZ-HM12NA / MUZ-HM12NA, MSZ-HM12NA & MUZ-HM12NA Mitsubishi Electric submittal, METUS Residential M-Series, P-Series and SMART MULTI Limited Warranty Statement
Specification sheet
MSZ-HM12NA & MUZ-HM12NA Mitsubishi Electric submittal
Last verified date
Jul 23, 2026

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Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA) strengths

  • SEER2 20 / HSPF2 10 with Mitsubishi dealer support and reliability.
  • 12,200 BTU rated heat at 47F for a 1-ton space.

Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA) weaknesses

  • Production Stopped/obsolete and R-410A - phase-out refrigerant.
  • EER2 9.9 - modest full-load cooling efficiency; no published 5F rating.
  • The current HX 12k (R-454B) is the recommended replacement.

Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA) climate suitability

Minimum heating ambient
not published
Rated heating at 5F
not published
Rated heating at 17F
7,600 BTU/hVerified - AHRI directory
Rated heating at 47F
12,200 BTU/hVerified - AHRI directory

Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA) electrical requirements

Voltage
not published
Voltage range
208/230VVerified - manufacturer product page
Phase
1Verified - manufacturer product page
Frequency
60 HzVerified - manufacturer product page
MCA
9 AVerified - manufacturer technical document
Breaker needed
not published
Maximum breaker size
not published
Maximum fuse size
15 AVerified - manufacturer technical document
Maximum cooling current
not published
Maximum heating current
not published
Manufacturer wire notes
not published

Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA) installation considerations

Liquid line
1/4 inVerified - manufacturer technical document
Suction line
3/8 inVerified - manufacturer technical document
Precharged length
not published
Included line-set length
Mitsubishi submittals publish line-size and maximum/precharged piping data; the installer supplies the line set.
Maximum line-set length
65 ftVerified - manufacturer technical document
Max line set per indoor
not published
Max height between indoor units
not published
Indoor dimensions
31-7/16 x 9-1/8 x 11-5/8 inVerified - manufacturer technical document
Outdoor dimensions
31-1/3 x 11-1/5 x 21-5/9 inVerified - manufacturer technical document
Indoor weight
not published
Outdoor weight
73 lbVerified - manufacturer technical document
Drain size
5/8 inVerified - manufacturer technical document

Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA) related systems and guides

Frequently asked questions

Can I install the Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA) myself, or do I need a pro?
Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA) is built for professional installation: the line set must be flared, evacuated, and charged, which requires EPA-certified refrigerant handling. Installing it outside the manufacturer's requirements can void the warranty, so budget for a qualified HVAC installer.
Will the Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA) keep heating in a cold winter?
Certified heating efficiency is 10 HSPF2. Match that published heating floor against your climate's design temperature - below the low-ambient rating, output can fall off or the system can pause to protect itself.
What electrical circuit does the Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA) need?
Published electrical requirements: 208/230V voltage, 9 A minimum circuit ampacity, and 15 A maximum breaker or fuse sizing. Confirm the final circuit against the unit nameplate and local code with a licensed electrician.
How far can the outdoor unit be from the indoor head?
The published maximum line-set length is 65 ft. Longer runs than the included set allows typically mean added refrigerant and a pro visit, so measure the planned routing before ordering.
What warranty does the Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA) carry?
The manufacturer publishes 5 years parts coverage and 7 years compressor coverage. Registration requirements and proof of qualified installation commonly affect coverage, so read the warranty terms before install day.

Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA) data sources

  • Mitsubishi Electric Trane HVAC US LLC: MitsubishiPro product record MUZ-HM12NA-U1Verified - manufacturer product page

    Covers Frequency, Phase, Voltage range, system.lifecycle_status

  • Mitsubishi Electric Trane HVAC US LLC: MSZ-HM12NA & MUZ-HM12NA Mitsubishi Electric M-Series HM submittalVerified - manufacturer technical document

    Covers electrical_spec.guaranteed_voltage_range, electrical_spec.indoor_mca_amps, Maximum fuse size, Minimum circuit ampacity, Drain size, Indoor dimensions and more

  • Air-Conditioning, Heating, and Refrigeration Institute: AHRI public detail 202680601 for MSZ-HM12NA / MUZ-HM12NAVerified - AHRI directory

    Covers AHRI certification number, Rated cooling capacity, EER2, Energy Star status, Rated heating capacity, HSPF2 (Region 4) and more

  • Mitsubishi Electric Trane HVAC US LLC: Residential M-Series, P-Series and SMART MULTI Split Air Conditioner and Heat Pump Systems Limited Warranty StatementVerified - manufacturer technical document

    Covers Compressor warranty, Parts warranty, Warranty notes

Mitsubishi Electric M-Series HM 12,000 BTU R-410A 208/230V (MSZ-HM12NA / MUZ-HM12NA) last updated

Jul 23, 2026