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North America // Technology

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A VERSATILE CO2 CONTRACTOR S o u t h - To w n / S C R h a s installed innovative transcritical CO 2 systems in three disparate Minnesota sites – a supermarket, a processing facility and an ice rink

— By Michael Garry

1 / Lunds & Byerlys has installed a transcritical CO2 system 2 / Ryan Welty, South-Town Refrigeration & Mechanical

Accelerate Magazine // June 2019

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ranscritical CO 2 refrigeration has proven to be a versatile a p p l i c a ti o n th a t c a n b e employed in a number of sectors, including supermarkets, industrial sites and ice rinks. As contractors, Minneapolis - based South-Town Refrigeration & Mechanical and its sister company SCR (St. Cloud Refrigeration), which cover the Upper Midwest of the U.S., have been equally versatile, installing transcritical systems in all three sectors in Minnesota over the past two years. “Now that we have systems in different settings, we have a good test of everything,” said Ryan Welty, vice president of sales and operations for both companies, which are co-owned by Welty’s father Pat and Mike Fitch. Fitch’s father, Don, started SCR, a non-union shop, in 1957, and the families purchased unionized South-Town in 2009.

Importantly, with a few years of experience working on CO 2 systems, Welty’s service technicians are “not scared” of them anymore,” he said. “And manufacturers have a good base as well.”

The first CO 2 project, handled two years ago by South-Town, was for a new innovation/technology center in Downtown Minneapolis where Jack Link’s Beef Jerky tests new products. An Advansor transcritical CO 2 system (from Hillphoenix), is used in a 10,000-ft² processing area along with Colmac custom DX evaporator coils and Micro Thermo Controls (from Sporlan). The system delivers a low-temperature capacity of 36.4K BTUH and a mediumtemperature capacity of 575.5K BTUH. The transcritical system leverages heat reclaim to create hot water used to preheat the water required for the wash down of the processing area. A unique aspect of the Jack Link’s project is that the CO 2 discharge gas is cooled in a heat exchanger by chilled (40°F-50°F ) water provided via underground pipes by Clearway Energy’s Energy Center; the Energy Center supports cooling and heating in 100 buildings in downtown Minneapolis. The cooled water prevents the CO 2 system from ever entering “transcritical