Uwajimaya, a supermarket chain with with locations in Greater Seattle and Oregon, is one of the largest Asian grocery retailers in the Pacific Northwest. The refurbishment of its 4,200m2 flagship store in Seattle included the replacement of its 20-year-old R22 system to a more efficient refrigeration system that would be better for the environment. 

Working with its longtime refrigeration service partner Refrigeration Unlimited Inc, Uwajimaya considered a CO2 system, “but the benefits simply didn’t outweigh the high cost and the maintenance difficulties,” said Shelby Powell, RUI’s business development manager.

“Solstice N40 provided everything we were looking for,” added Miye Moriguchi, Uwajimaya’s real estate and facilities manager. “It met our goals for sustainability and energy efficiency, plus it allowed us to design a completely new system that simplified monitoring and control.”

Working with Hussmann, RUI replaced all of the cases and walk-ins, swapped out the refrigeration racks for Hussmann Protocols, replaced the condensers and switched the refrigerant to R448A, marketed by Honeywell as Solstice N40. 

Solstice N40 is a non-flammable refrigerant with GWP of 1273.

The Hussmann Protocol compact multiple compressor refrigeration units are an alternative to traditional backroom rack systems. Individual Protocol units are placed throughout the store or on the roof, close to the display case loads. Being placed closer to the load means 50-70% less piping and 60-80% less refrigerant.

Protocol units uses high efficiency, vapour-injected scroll compressors for both low- and medium-temperature applications. These supply a total of 85 Hussmann Insight refrigeration cases.

In addition to the four Hussmann Protocols, the system employs three air-cooled condensers with remote monitoring. It also incorporates a Therma-Stor heat recovery system to provide hot water from captured waste heat from the refrigeration system. 

The retrofit to Solstice N40 and the new system paid dividends right away. Based on estimated annual energy savings of 357,000kWh, energy provider Seattle City Light provided a rebate of more than $64,000 to help offset the cost.

The upgrade is also said to have simplified maintenance duties. Every case can now be monitored and adjusted individually, with all information available on a dashboard compatible with mobile devices.