Keeping up with momentum: Manufacturers on getting UL listed in North America

By Silvia Scaldaferri, May 06, 2013, 14:52 4 minute reading

Several refrigerant motor-compressor manufacturers such as Dorin, Bitzer and Emerson have already received UL Certification for their CO2 compressors for American and Canadian markets, and others such as EcoThermics expect approval later this year. The internationally recognised safety certification reinforces product credibility to end-users considering all-natural refrigeration solutions, an increasingly popular choice in North America for commercial and industrial applications.

UL (Underwriters Laboratories) approval helps manufacturers testify that a compressor meets global safety standards, an important pass for end-users that can strengthen the acceptance of natural refrigerants in newer markets. In a recent interview with, Emerson Climate Technologies reveals the history of their CO2 compressor line which has obtained UL recognition.

Emerson: In 2008, Emerson Climate Technologies introduced the Copeland Scroll™ ZO compressors for subcritical CO2 operation with Underwriters Laboratories (UL) recognition. These compressors are approved for operation up to 42°F (5.6 °C) condensing temperature, which corresponds to 625 psig (43 bar) condensing pressure. In January 2013, Emerson received UL recognition for its new line of semi-hermetic compressors for transcritical CO2 operation. These 4MTL compressors are approved for applications with a high side pressure relief valve set at 1985 psia or 135 bar. Which types of your CO2 compressors have already been certified or are currently in the pipeline for being certified? Which CO2 system types, sizes and applications do these cover?

Emerson: The Copeland Scroll™ ZO range from 1 to 6 horsepower (HP) and are available in 230, 380, 460 and 575 volts. They are also available with Copeland Scroll DigitalTM modulation providing 10-100 percent variable compressor capacity. The new line of semi-hermetic compressors sold in the North American market is currently available in the 10 to 30 horsepower size range in both 460 and 575 volts. These semi-hermetic compressors are approved for variable speed operation. We are also in the process of releasing larger transcritical CO2 displacements for the North American market. Both the Copeland Scroll ZO and the Copeland semi-hermetic 4MTL are ideal for commercial refrigeration applications with evaporating temperatures ranging from -55ºF to 40ºF (-48 ºC to 4 ºC). Specifically, Emerson sees early adoption in supermarket refrigeration systems including CO2 cascade and booster configurations.

Bitzer: We have received UL approval on compressors suitable for both subcritical and transcritical application and in nominal horsepower ranging from 1 to 30HP.

EcoThermics: Our first compressor [to be certified] is the AT80SH semi-hermetic transcritical CO2 compressor (30 HP). Primary initial applications will be in heat pump water heaters in commercial and industrial markets.

Our range of CD400 transcritical and subcritical CO2 compressors have been UL approved and is suitable for applications such as condensing units, supermarket racks and industrial heat pumps. What has been the motivation for seeking UL certification, and what are your expectations regarding the uptake of CO2 technology in various applications in North America?

Emerson: UL recognition is critically important in the refrigeration industry as it identifies compressors that meet global safety standards, ensuring products have been thoroughly tested and achieve a pre-determined set of international electrical and mechanical guidelines.
For those customers who want compressors that use a natural refrigerant, Emerson’s new line of transcritical compressors have received UL recognition,” said Mitch Knapke, market manager, food retail, Emerson Climate Technologies.
UL recognition is a critical step to increasing CO2 adoption as it ensures retailers the compressors have met stringent safety tests,” he continues.
With an increased global interest in the environmental impact of refrigeration systems, Emerson Climate Technologies expects increased usage of alternatives to hydrofluorocarbon (HFC) refrigerants that have lower global warming potential (GWP), including HFO blends and natural refrigerants such as CO2. Emerson believes subcritical CO2 cascade systems will gain more traction in the warmer climates and transcritical CO2 systems are particularly well-suited for colder climates. In addition to CO2 compressors, Emerson offers a comprehensive portfolio of CO2 controls and flow components.

Bitzer comments that they seek to satisfy the needs of their OEM customers as the CO2 market grows and similarly EcoThermics aims to increase customer acceptance of CO2-based products which are steadily gaining interest and market share in North America for a variety of reasons including sustainability, energy-efficiency, long-term cost efficiency and reduced carbon footprint. Dorin comments that they need to keep up with the “momentum” CO2 is gaining in North America in order to be considered as one of the compressor leaders in the field.

UL listing is a step forward to bringing sustainable refrigeration to the North American market and paves the way for the widespread adoption of HFC-free CO2 technology in supermarkets throughout the US and Canada.

More about UL (Underwriters Laboratories)

UL (Underwriters Laboratories) was established in 1894 as a global independent safety product safety testing and certification organisation with expertise in innovating safety solutions from the public adoption of electricity to new breakthroughs in sustainability, renewable energy and nanotechnology.


By Silvia Scaldaferri

May 06, 2013, 14:52

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