Mitsubishi Heavy Industries launched its very own Q-Ton heat pump water heater for commercial applications in late 2011. Using scroll and rotary compressors, initially, the Q-Ton transcritical heat pump faced the same challenges as its predecessors in cooler temperatures.

Hironaki Fujiki of Mitsubishi Heavy Industries presented the results of the company’s extensive field tests conducted in 2011/12 under temperatures as low as -20°C – in Iwate, Hokkaido and Toyama.

Like the EcoCute, Mitsubishi was having difficulties reaching the Q-Ton’s 90°C hot water supply capacity in temperatures below 7°C, but after extensive testing in the most severe conditions, was eventually able to achieve this. 

Q-Ton: As cold as ice

  • Field tests down to -20°C the supply of 90°C was assured
  • Cost savings: 61% reduction in running costs 
  • CO2 emissions reduced by 29%
  • Suitable for ambient temperatures as low as -7°C 
  • Highest COP of 4.3 in the industry

“According to the results of the field tests we materialised the capacities and efficiency as we had planned,” Fujuki said. “We were able to show the advantages in terms of the cost reduction to the customers. Even in a (heavily snowed) area like Iwate we proved the Q-Ton is still able to boil the water as we’d expect.”

Fujuki insisted the Q-Ton is suitable for various applications including a hot springs in Hokkaido, which now has four hybrid systems after upgrading to the Q-Ton, while Doosan Heavy Industries, a sustainable development company, have 22 Q-Tons installed.

Other Q-Ton installations include: 

  1. nursing home in Fukishima, which used an electric heater but needed to upgrade its ageing system to produce a greater capacity of hot water. The nursing home achieved a reduction of 70% in running costs.
  2. school lunch facility in Shizuka serving 6000 meals a day installed 12 Q-Tons mainly to supply hot water for the dishwashers.
  3. food factory where the Q-Ton is used to supply hot water for cleaning, a hot spa, which is still being installed, and a sauna in South Korea.

In fact, Mitsubishi Heavy Industries plans to target the region specifically.

“We have many future plans, especially in South Korea; where there are several cold areas and this is where the Q-Ton (shines), such as hot springs, spas, dormitories and industrial applications.”

Ultra-Eco-Ice system: patented brine ice thermals storage 

Yamato’s managing executive officer Sadao Nishimura presented the company’s Ultra-Eco-Ice (UEI) system for the second year in a row. The CO2 refrigeration and brine-ice thermal storage system is specifically designed to retrofit existing HCFC/HFC display cases to use brine.

The innovative UEI system, which is now used in 13 different facilities, allows end users the opportunity to upgrade their HFC systems rather than replace the entire case. Yamato’s viable solution will help address over 50% of existing facilities in Japan that still use HCFCs but must be phased out by 2020, in order to comply with the Montreal Protocol.

Coping with peak demand: converting thermal energy

The patented Ultra-Eco-Ice system is a next generation refrigeration system that stores cold energy during nighttime, converting it for refrigeration and air conditioning inside the store and display cases. During the night, the CO2 refrigerators produce low-temperature brine ice (-6°C), accumulating it in the thermal storage tank.

This allows supermarkets to better cope with peak demand during the day, while in winter the system is able to recycle the condensing heat recovered from the refrigerators and use it for in-store floor heating.

The UEI includes a CO2 refrigerator (6 MPa) and brine ice storage tank (outside), which optimises the brine system’s (0.3 MPa) indoor display case.

Peak shift CO2 vending machine

The Coca Cola Company first introduced their innovative CO2 peak shift vending machines in 2013. Designed to reduce electric power consumption during peak hours, following the Japan earthquake and tsunami of 2011, the Coca Cola Company added 28,000 machines in 2013 and 83,000 in 2014. According to Yoshinari Okuyama, Coca-Cola Tokyo Research & Development Co. Ltd., the vending machine keeps drinks cold maximum of 16 hours without running a compressor. This means that during the summertime daytime the compressor does not need to be run.

The vending machine has received the following recognition: 

  • Energy Conservation Grand Prize from the Japanese Minister of Economic, Trade and Industry (METI)
  • Excellence Award for Energy Saving from the “Eco-Products Awards Steering Committee”
  • Letter of Appreciation from the Heat Pump & Thermal Storage Technology Center of Japan (HPTCJ)
  • GPA (Goodwill Promotion Alliance) Gold Award and Jury’s Special Award sponsored by “Japan Promotional Marketing Institute


Mitsubishi Heavy Industries Partner Page
ATMOsphere Asia 2015 events page
Yoshinari Okuyama: Phase out of F-gases and shift to natural refrigerants
Sadao Nashimura: F-gas free Ultra Eco-Ice CO2 system
Hironari Fujiki: Mitsubishi’s Q-Ton heat pump water heater

Author jamesranson