In November 2019, Tokyu Department Store, a major Japanese chain, opened a new 47-story high-rise commercial complex called Shibuya Scramble Square, just a few blocks from Tokyo’s well-known “Shibuya Scramble Crossing” intersection.

The company installed several CO2 plug-in display cases combined with a water loop system in the complex’s basement food-shopping area. The combination of CO2 plug-in equipment with a water loop system in a retail department store setting is relatively new in Japan, where CO2 outdoor condensing units in convenience stores are dominant.

The innovation represents a new opportunity for end users such as department store retailers to employ natural refrigerant systems, especially those located in densely populated Tokyo neighborhoods, where space is always limited.

Water Loops Solve Space Restrictions

In the 2nd-floor basement of the Shibuya Scramble Square high-rise tower, two food suppliers, Head Line (a rotating showcase of various food makers) and Sanwein (a vendor specializing in Taiwanese delicacies), use seven pieces of specially designed CO2 water-cooled plug-in showcases.

While Tokyu Department Store aimed to use natural refrigerant equipment, the space restrictions and the underground location of the food sales area meant that the conventional CO2 air-cooled condensing unit type system was not seen as a viable option.

So Tokyu Department Store worked with Japanese OEM Panasonic and Japanese refrigeration installer Hama Refrigeration Industries to design and install CO2 plug-in showcases that would be cooled by a water loop. The cooling tower is located outside on the 13th floor. Tokyu Department Store chose to forego using subsidies for this project due to a tight construction and delivery schedule.

Tokuo Sato, Director of Hama Refrigeration Industries, said that in addition to preventing waste heat from being released on the sales floor, water- cooled systems are a good option for commercial facilities with limited space, and help businesses transition away from synthetic refrigerants.

“Several major department stores have called for water-cooled CO2 showcases,” said Sato. “Looking ahead, it is better to transition away from fluorocarbons now rather than half-way through with low- GWP refrigerants such as mixed fluorocarbons.”

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