Danfoss Climate Solutions recently held an online event entitled RETHINK Live: Cooling in the Green Transition, which explored sustainable cooling practices and provided an opportunity for industry experts to share their thoughts on how to transform cooling systems in order to lower emissions and improve efficiency.

“The purpose of this event is to spark a larger conversation on how we can uncover new sustainable ways to operate in the world of HVACR,” said Magdalena Mydlo-Garcia, senior marketing communications manager at Danfoss. “We are excited to bring together industry leaders to discuss the latest innovations in commercial and industrial refrigeration.”

One of the topics covered in a panel discussion at the event was the growing use of CO₂ in commercial refrigeration systems. Experts tackled some of the myths surrounding CO₂ and discussed the challenges and opportunities this natural refrigerant offers both food retailers and contractors.

Costs and Benefits

Thanks to regulations taking effect around the country, there is a growing movement towards using natural refrigerants such as CO₂ in commercial refrigeration systems. California has led the transition away from high-GWP HFC refrigerants by adopting rules for commercial refrigeration equipment that started this year. As of January 1, 2022, there is a 150 GWP limit for new or fully remodeled facilities that utilize commercial refrigeration equipment containing more than 50 pounds of refrigerant, while there are varying requirements for existing facilities.

Other states are following California’s lead, which is why CO₂ — with a GWP of 1 — is so appealing, as many consider it to be a ‘future-proof’ solution. As Peter Dee, food retail sales director at Danfoss, noted, “It's better to go with a natural refrigerant once and for all, then we don't have to worry about what's happening in the future. I think organizations out there are willing and able to support customers that want to transition to these natural refrigerants like CO₂.”

Dee added that besides having a low GWP, CO₂ systems offer other benefits, such as better technology, which can allow additional data to be obtained through the food retailer’s IoT platforms. In addition, higher efficiency can be achieved by various architectures, such as distributed systems, and the technology also offers additional safety factors, which gives a greater level of comfort to the end user.

Because CO₂ systems incorporate a lot of technology, their first cost is often higher, which can be a challenge that is difficult to overcome, said Derek Gosselin, director of technical product support at Hillphoenix. But these technologies can result in operational savings, which need to be taken into consideration. For example, CO₂ systems incorporate case controls and electronic expansion valves (EEVs), which add to the cost, but also offer the ability to adjust superheat, which can lead to better case performance, he said.

“First cost is always key, and it’s been one of our major challenges, because it costs more to do new technology,” he said. “So we have to overcome that and have a better understanding of where total cost of ownership comes into play — refrigerant management, energy savings, installation savings — beyond just the product.”

As far as installation is concerned, Gosselin said that on average, store owners can save 10% of installed costs, because the refrigerant lines for a CO₂ system are one or two sizes smaller, so they require less insulation, smaller pipe hangers, and less labor to install. There is a savings on refrigerant as well.

“With a charge setup, let’s say you're doing 2,000 pounds of R-448A or R-449A at $20 or so a pound, versus 1,700 pounds of CO₂ at $2 a pound. It's a big difference,” he said. “Again, it goes back to the total cost of ownership. You can't look at first costs — you have to look at the total installed applied costs and where the benefits come on efficiency, refrigerant management, and all the things that make up the total cost of ownership.”

Chris Brown, technical support manager at Danfoss, added that significant savings can also be found in the wiring of CO₂ systems. He noted, “Instead a centralized control strategy where there is a ton of wiring running throughout the store over long distances, we're now just talking about two wires to each point, each circuit to the case controls, which is much less wiring, much less installation time.”

As for energy savings, Dee noted that through the use of EEVs and case controllers, CO₂ systems can achieve an energy savings of 11% to 15%, provided they are set correctly.

“They have to be optimized, and then you have to use your IoT platforms to monitor and manage the efficiency in your store,” said Dee. “Customers who have moved to these technologies and these natural refrigerants have seen these advantages. They calculated the return on investment. Particularly in other regions like Europe, where they’re seeing that efficiency.”

Training

Of course, before end users can experience the benefits of using a CO₂ system, they need to find someone who understands the technology and can properly install it. With the current labor shortage, there are concerns about whether the technician base will be available to install and service CO₂ systems now and in the future.

“I think we, as an industry, need to work together to make sure that we are attracting and recruiting new talent into the industry in all of our trades, because it impacts a lot of different areas,” said Gosselin.

To that end, Hillphoenix’s training center has partnered with several key retailers to provide a certification program that installing contractors must complete before they can bid on any of their CO₂ projects. Gosselin believes that kind of certification can be expanded across the industry in order to train the technicians that are needed to support the growth of CO₂.

Danfoss and other OEMs also support startup of new applications, as well as help, support, and train contractors and end users on the use of CO₂, said Dee.

“It's all about training,” said Dee. “I think the more we can get in front of that out there, the more skill sets we're building up in the industry. In the long term, that's going to make it a lot easier for everybody to transition to these natural refrigerants.”