Webinar on introduction to CO2 commercial refrigeration

By Clémence Girard-Reydet, Feb 24, 2012, 00:00 4 minute reading

In the latest webinar hosted by the GreenChill Partnership on 9 February, Rusty Walker, senior corporate trainer at the Hill Phoenix learning center, presented an introduction to CO2 refrigeration systems in commercial refrigeration.

After giving a series of useful definitions and presenting the benefits of using CO2 as a refrigerant, Rusty Walker presented an overview of the main CO2 systems currently available on the market for commercial refrigeration. His explanations included specifics for low temperature CO2 secondary coolant systems, low temperature CO2 cascade or subcritical systems and CO2 transcritical booster systems.

The second part of the webinar, a question & answer session, focused mainly on CO2 transcritical booster systems and discussed the most important drawbacks that prevent experts from choosing a CO2 refrigeration system. Walker answered technical questions and reassured the audience about CO2 operation and maintenance costs as well as safety issues.

CO2 transcritical booster system advantages
  • Zero HFC
  • A single refrigerant in the system
  • Low cost of CO2 compared to other refrigerants
  • Less piping and smaller installations that are easy to maintain
  • Booster technology suppresses the need for a heat transfer operation between low and medium temperature
  • Better efficiency than other systems in cooler climates

Psychological barriers to CO2 only refrigeration systems

It seems that a lot of professionals have difficulties in considering CO2 as an effective solution when CO2 emissions are responsible for global warming and climate change. But Walker explained that every other refrigerant available on the market has a global warming number close to 2000. CO2 on the other hand has the lowest global warming potential (ODP=0, GWP=1) even compared to other natural refrigerant like hydrocarbons or ammonia.

Professionals are also concerned about how and where to find the industrial grade CO2 they will need to operate their system, as manufacturers and refrigerant wholesalers do not yet stock CO2. Walker insisted that retailers would quickly stop worrying about supply as soon as they started using the system and were able to realise that consumption of CO2 is very small and that CO2 can be easily ordered from big gas suppliers.

For now retailers opting for a CO2 system can order their CO2 before starting to operate it and can easily store small quantities of CO2 themselves. Walker added that as CO2 systems are becoming an important business, customers should include gas provision in their contracts with manufacturers.

Concerning operating and maintenance costs, Walker reminded listeners that a full CO2 system is cheaper to operate than a traditional HFC system or a cascade system as it includes fewer parts and components and uses smaller pumps. Significant engineering progresses have been made the last 10 years and new pieces and components specially designed for high pressure CO2 are more reliable making the whole system more energy and cost efficient.

For Keilly Whitman from GreenChill, who was moderating the webinar, it is also very important that users try to customise the system to their needs in order to reach the highest level of energy efficiency in the first months of implementation.

Finally, concerning safety issues, Walker tried to dispel misperceptions. Technicians still consider transcritical technology as more complicated to operate particularly because of the higher operating pressures.

For him, the only special precaution to take with a CO2 refrigeration system, compared with other systems where you can easily isolate the component you have to work on, is that you have to be careful not to let the pressure decrease too much in the system to avoid CO2 cooling in the pipes.

Walker insisted on the fact that operation of CO2 systems is no more complicated than any other system. Technicians need only to receive better information. Moreover, operator training should be included in manufacturers’ offers.

GreenChill webinars available online

Everybody can freely access the webinar on introduction to CO2 Refrigeration Systems as well previous webinars (GreenChill’s Store Certification Program, Overview of Supermarket Advanced Refrigeration Technology, Overview on Commercial Refrigerants - where are we headed?, CO2 Use in Commercial Refrigeration) clicking here.

Background GreenChill and Hill Phoenix learning center

This webinar is the first of a series of 5 webinars dedicated to CO2 refrigeration systems organised by the GreenChill Partnership. This partnership between the U.S Environment Agency and food retailers has been launched to help reduce refrigerant emissions and decrease their impact on the ozone layer and climate change.

The Hill Phoenix learning center is an online platform providing programs, webinars and online classes based on Hill Phoenix product knowledge but also on its expertise in Sustainable Design, Green Building Materials, and LEED Certification.

If you would like to contact Hill Phoenix for any enquiries, you may send a request to Scott Martin directly.


By Clémence Girard-Reydet

Feb 24, 2012, 00:00

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