Press Information

(Domestic sales only)
MHI Thermal Systems to Launch Four Room Air-Conditioner Models for Cold Regions
-- Models Meet Standards for Heating Air Conditioners from Hokkaido Electric Power and Tohoku Electric Power --


・ Non-stop operation limits the falloff in temperature when operating in defrost mode, allowing for operation in heating mode at minus 25°C

・ Shorter startup times in morning for comfortable start to heating

・ Incorporates function to maintain room temperature at around 10°C, preventing excessive coldness during absences or overnight

SXK Series
SXK Series

Tokyo, May 30, 2019 – Mitsubishi Heavy Industries Thermal Systems, Ltd., a Group company of Mitsubishi Heavy Industries, Ltd. (MHI), will from mid-July successively launch four models of residential-use air conditioners specifically designed for cold regions. The SXK Series of high-spec models for cold regions are highly energy efficient with an exceptional annual performance factor (APF)(Note1), and incorporate unique functions to maintain a comfortable living environment in cold areas. These models also use filter holders made from a synthetic resin containing recycled tea leaves(Note2), marking a major advancement in the efficient use of resources.

All four models incorporate a hot gas bypass non-stop heating system, a first time for an R32 refrigerant home air-conditioner, which limits the falloff in temperature when operating in defrost mode (non-stop heating). The incorporation of this function allows these units to operate in heating mode in temperatures as low as minus 25°C, earning them certification as "Attaka Air-con" recommended by Hokkaido Electric Power Company(Note3). The series has also received certification from Tohoku Electric Power Company as "Tohoku Electric Power Company recommended Heating Air-con"(Note4) for achieving a prescribed energy consumption rate when operated in heat mode at a temperature of minus 15°C. The SXK Series also incorporates a "hot standby" function to shorten heating startup times, a function to keep a room temperature at around 10°C to prevent excessive coldness during absences or overnight, an exterior unit anti-freeze heater to prevent damage to the equipment when the temperature drops, and a snow protection fan control function to prevent the exterior unit's fan from being covered by snow.

The new models will also utilize filter holders made from a synthetic resin containing recycled tea leaves, developed by Ito En Ltd. as part of its Used Tea Leaves Recycling System. This feature has been popular in ordinary air conditioning models. A mass production system for resin molding has been established at MHI Thermal Systems' factory in Thailand.

Further, the SXK Series will incorporate the same interior clean operation function as ordinary models, and can also be used in tandem with three models in the "roomist" SHK Series of hybrid evaporative warm-mist humidifiers sold by MHI Group company Mitsubishi Heavy Industries Air-Conditioning & Refrigeration Corporation. The humidifier starts and stops automatically in response to signals it receives from the air-conditioner's humidity sensor, maintaining the set humidity.

MHI Thermal Systems, with these four cold-region models in its product lineup, will meet a broad range of user needs in Japan.

  • 1Annual Performance Factor (APF) is a performance index in which the total capacity needed for heating and cooling throughout the year is divided by the energy consumption of the air conditioner. Larger numbers represent greater energy efficiency.
  • 2See "Physiological Functions of Japanese Green Tea Components" from the World Green Tea Association (
  • 3Guaranteed to operate in heating mode at minus 25°C.
  • 4Units that can operate at minus 15°C, and that meet Tohoku Electric Power's standard COP (coefficient of performance) for energy efficiency during heating season.

About MHI Group

Mitsubishi Heavy Industries (MHI) Group is one of the world’s leading industrial groups, spanning energy, smart infrastructure, industrial machinery, aerospace and defense. MHI Group combines cutting-edge technology with deep experience to deliver innovative, integrated solutions that help to realize a carbon neutral world, improve the quality of life and ensure a safer world. For more information, please visit or follow our insights and stories on