Japanese OEM Mitsubishi Heavy Industries (MHI) Thermal Systems has announced it will release new 10HP and 20HP CO2 (R744) condensing units featuring the company’s new M-DIOMAC packaged oil management system this summer in Japan.
In a press release, MHI said the M-DIOMAC system, short for “direct oil management control,” is made up of a dedicated system controller and remote controller. The company said the packaged oil management system leads to easier installation because it “simplifies on-site adjustments of the refrigeration units.”
“Direct control of the cooling unit’s expansion valve enables effective oil management, resulting in outstanding reliability,” MHI said. The company noted that the valve itself must be purchased from its controller manufacturing partner, Carel.
The 10HP and 20HP CO2 outdoor condensing units offer applications for both refrigeration and freezing, with operating temperatures between −45 and −5°C (−49 and 23°F) in ambient conditions ranging from −15 to 43°C (5 to 109.4°F). The 10HP unit offers 2.98TR (10.48kW) of refrigeration capacity while the 20HP unit provides 5.96TR (20.96kW) of refrigeration capacity.
Up to three of the 20HP condensing units can be interconnected for a maximum 60HP configuration, according to MHI. The 10HP model allows the interconnection of up to eight indoor cooling units – including showcases and unit coolers – while the 20HP model can interconnect up to 16 units. The remote controller, which features a 7-inch (17.8cm) color display, enables users to monitor the cold room temperature, set temperature, degree of superheat and opening degree of expansion valve for up to eight cooling units.
The new 10HP and 20HP condensing units are the latest additions to MHI’s C-puzzle CO2 condensing unit lineup. First marketed in 2017, the C-puzzle series incorporates MHI’s proprietary two-stage compressor, which uses both a scroll and rotary compressor. MHI first offered 10HP and 20HP C-puzzle condensing units, which were followed by a 40HP model in 2020 and an 80HP model in 2021.
Japanese regulations and subsidies
MHI said it predicts demand for CO2 condensing units in Japan will increase “both for new installations and replacements” due to the Act on Rational Use and Proper Management of Fluorocarbons. The law, which was passed in Japan in 2001 and amended in 2015, requires all commercial condensing units with a compressor whose output exceeds 1.5kW (0.43TR) refrigeration capacity to adopt refrigerants with a GWP below 1,500 by 2025.
“[With a GWP of 1,] condensing units using CO2 refrigerants are not affected by refrigerant regulations,” MHI said.
Since 2005, Japan has offered natural refrigeration equipment installation subsidies through its Ministry of the Environment (MOE) and Ministry of Economy, Trade and Industry. Last year, Japan’s MOE extended the subsidies through 2027 with ¥7 billion ($47 million/€43.9 billion) allocated for fiscal year 2023.
“Direct control of the cooling unit’s expansion valve enables effective oil management, resulting in outstanding reliability.”MHI