Mitsubishi Hyper-Heat GX 18,000 BTU

Last updated: October 22, 2026

Mitsubishi Hyper-Heat GX 18,000 BTU
4.2/5#7 of 22 in 18,000 BTU mini-splits
4.2

Mitsubishi’s mainstream Hyper-Heat line keeps its full rated heat at 5 °F and heats down to −13 °F. The FX goes further in deep cold and efficiency.

  • 18,000 BTUSize
  • 19,000 Btu/hHeat at 5 °F
  • 100%Kept at 5 °F
  • 10 / 22.5HSPF2 / SEER2
  • Pro installInstall
See it at Mitsubishi

No store we check sells it online; the maker lists where to buy or who installs it.

Pros
  • Keeps 100% of its rated heat at 5 °F: 19,000 Btu/h
  • 10-year parts and compressor warranty once registered
Cons
  • Needs a licensed HVAC installer: a self-install voids the warranty

How it scores

The rating comes from 4 measured or published factors, each scored 0-100 against fixed reference points for its size. How we rank explains each one.

Specifications

Capacity (certified)
Size (nominal)18,000 BTU
Cooling at 95 °F18,000 Btu/h
Heating at 47 °F19,000 Btu/h
Heating at 17 °F (max)22,400 Btu/h
Heating at 5 °F (max)19,000 Btu/h
Heat kept at 5 °F100%
Efficiency (certified)
HSPF2 (Region IV)10
SEER222.5
EER214.1
COP at 5 °F1.80
ENERGY STARENERGY STAR Cold Climate
AHRI certificate215862740
Operating range
Heats down to-13 °F
Cooling range14 to 115 °F
Installation
Installed byProfessional (sold through installers)
Line set connectionFlare fittings (vacuum pump needed)
Line setup to 100 ft
Voltage230 V
RefrigerantR-454B
Indoor unitMSZ-GX18NL
Outdoor unitMUZ-GX18NLHZ
Build
Indoor noise28–49 dB(A)
Outdoor noise54 dB(A)
Wi-FiBuilt in
Weightindoor 37 lb / outdoor 117 lb
Warranty10 yr compressor, 10 yr parts
Warranty with DIY installNo, a licensed installer is required
Released2025-02

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