Mitsubishi MXZ-SM42NLHZ 42,000 BTU Hyper-Heating H2i® Smart Multi Heat Pump Unit

Introducing the Mitsubishi 42,000 BTU Multi-Zone Hyper Heat Pump Outdoor Unit MXZ-SM42NLHZ , a high-performance multi-zone system designed for precise, efficient, and quiet heating and cooling in up to five zones. Powered by Mitsubishi’s trusted INVERTER technology, the MXZ-SM42NLHZ delivers exceptional comfort year-round with enhanced low-temperature performance. This model requires a compatible Mitsubishi branch box when paired with M- or P-Series indoor units.

The MXZ-SM42NLHZ offers a maximum cooling capacity of 42,000 BTU/h and an impressive maximum heating capacity of 48,000 BTU/h at 47°F , ensuring outstanding performance in a wide range of climates. As part of Mitsubishi’s Hyper-Heating line, it maintains full rated heating output even in severe cold—delivering 48,000 BTU/h at 17°F , and sustaining powerful performance down to -13°F . Efficiency ratings reach SEER2 up to 21.5 , HSPF2 up to 11.1 , and COP values up to 4.10 at 47°F , earning ENERGY STAR® certification in non-ducted configurations.

Built for longevity, the MXZ-SM42NLHZ features Mitsubishi’s Blue Fin anti-corrosion coating on the heat exchanger and base panel, tested for 2,000 hours under ASTM B117 standards. A twin rotary INVERTER-driven compressor (model MRK53FFJMC-L) ensures precise output modulation, while maintaining quiet operation—just 50 dB(A) in cooling and 54 dB(A) in heating . Finished in a durable Munsell 3Y 7.8/1.1 exterior , the unit also comes with a built-in base pan heater for reliable operation in freezing conditions.

Installation flexibility is excellent, with support for piping runs up to 492 ft total and a maximum height difference of 164 ft between outdoor and indoor units. The system can connect to up to five indoor units with a branch box , supporting a maximum connected capacity of 54,600 BTU/h. It is factory pre-charged with 6 lbs. 10 oz. of R454B refrigerant , reducing on-site setup time.

Advanced safety protections include compressor overcurrent detection, compressor thermal protection, fan motor overheating/voltage safeguards, and high-pressure safety controls. Despite its robust heating capacity, the MXZ-SM42NLHZ remains compact at 41-11/32" W x 13" D x 52-11/16" H and weighs 283 lbs , ensuring it fits seamlessly into most installation sites.

Whether cooling through the hottest summer days or heating through extreme winters, the Mitsubishi MXZ-SM42NLHZ delivers powerful, efficient, and whisper-quiet comfort—making it an ideal choice for homeowners seeking dependable multi-zone climate control with superior cold-weather performance.