SCM Ref NZ Supplied Over 80 Transcritical CO2 Systems

Auckland-based SCM Ref NZ, a subsidiary of Beijer Ref, has supplied over 80 transcritical CO2 (R744) systems in New Zealand, according to Product Development Manager Chris Gibbons.

Its CO2 installations range in size from 6kW to 1.2MW (1.7 to 341TR), Gibbons told NaturalRefrigerants.com. He added that SCM Ref NZ is the only manufacturer in New Zealand to locally produce a standard range of transcritical CO2 condensing unit lines.

The company started production of its CO2 SMTDX line in 2021. Its off-the-shelf range is available in five models with capacities of 6, 10, 15, 20 and 30kW (1.7, 2.8, 4.3, 5.7 and 8.5TR) at 30°C (86°F) ambient, along with three tandem compressor models offering 30, 36 and 42kW (8.5, 10.2 and 11.9TR) capacities. SCM Ref NZ supplies all larger CO2 systems through fellow Beijer Ref group member SCM Frigo.

“We have an ideal environment for CO2 refrigeration, with summer high ambient temperatures in New Zealand daily averaging between 20 and 26°C [68 and 78.8°F],” Gibbons said. “Our local production capability significantly reduces lead times for CO2 equipment compared to imported units.”

The ATMOsphere report “Natural Refrigerants: State of the Industry 2024” on commercial and industrial refrigeration estimated that as of December 2024, 240 supermarkets and 60 industrial sites in New Zealand operated with transcritical CO2 systems. ATMOsphere is the publisher of NaturalRefrigerants.com.

Climbing sales: SCM Ref NZ has primarily installed CO2 systems for food industry applications, including cold storage, meat processing plants and supermarkets. Recently, the company has seen growing adoption of the technology in a wider range of applications, including small-format installations.

The largest single CO2 rack installed by the company is a 790kW (1,454TR) unit manufactured by SCM Frigo. Some locations use multiple racks to provide MW cooling capacities.

COPs for CO2 systems can run between 4 and 5 in subcritical conditions, accounting for more than 90% New Zealand operations, subject to location, Gibbons noted.

“End users cannot believe the energy savings they get when they transition from synthetics to CO2,” Gibbons said.

Selection benefits: Using data from a recent medium-sized supermarket project that increased both the retail area and refrigeration load, Gibbons highlighted results commonly seen by the company’s New Zealand customers when transitioning from synthetic refrigerants to CO2.

Two racks provide the new supermarket 130kW (37TR) of cooling capacity, with reclaim heat supplying hot water to the air handling unit for store comfort heating in the winter.

With a smaller footprint, the CO2 racks use roughly 35% less charge than a comparable synthetic system and operate quieter, according to Gibbons. “Its reduced size, including the smaller diameter pipes, makes it more economical and easier to install,” he said.

“[The store], with a 30% increased refrigeration load, consumes less power now than the original synthetic set, even in summer,” Gibbons said.

New product: With New Zealand’s emissions trading scheme making synthetic refrigerants “extremely” expensive, Gibbons built a CO2 ice builder for use in the country’s expansive dairy industry.

SCM Ref NZ designed and constructed the evaporator coils using K65 copper piping and linked the unit to its New Zealand-built SMTDX10 transcritical CO2 refrigeration pack.

The unit takes advantage of off-peak energy rates by generating and storing up to 500kg (1,100lbs) of ice.

When energy prices are high, instead of building ice, cold water circulates through the ice tank to a heat exchanger where it absorbs heat from warm milk to cool it down to the required 4°C (39°F) storage temperature.

Every single customer that I’ve got on board with CO2 in the past five years has never looked back.

Chris Gibbons, Product Development Manager at SCM Ref NZ