Refrigeration Systems Are Going Au Naturel
Natural refrigerants such as propane and CO2 are becoming more popular
In last month’s editorial, I discussed how mildly flammable (A2L) refrigerants will be available in the refrigeration and air conditioning markets over the next few years and that contractors and technicians should obtain additional training soon in order to learn how to safely handle and transport these new products.
But there are other options on the refrigeration side that HVACR professionals need to learn about as well. So-called natural refrigerants such as CO2 and propane are becoming more popular, due to changing regulations at the state level – and likely the federal level soon -- that are seeking to reduce emissions of high-GWP refrigerants such as R-404A. With a GWP of 1 for CO2 and 3 for propane (R-290), this type of refrigeration equipment is about as “future-proof” as you can get.
Not surprisingly, California was the first state to craft regulations designed to dramatically reduce HFC emissions in refrigeration equipment. For food retailers, this means that starting January 1, 2022, there will be a 150-GWP limit for new or fully remodeled facilities in California that utilize commercial refrigeration equipment containing more than 50 lbs. of refrigerant. For existing facilities, there are varying requirements that depend on the end use and number of facilities owned. It would not be surprising to see the federal government adopt these limits as well, but we’ll see when EPA releases its regulations this month.
Like A2L refrigerants, natural refrigerants are not a drop-in solution, as they require the system to be completely replaced. This means a greater expense for food retailers, and it also requires additional training for technicians.
Propane is already widely used in self-contained refrigeration equipment around the country, with some food retailers even experimenting with stores that only utilize propane for their refrigerated cases. Part of the appeal is that self-contained propane units contain a very low charge of refrigerant; they are highly flexible for merchandising purposes; and they have a low leak rate of about 2 percent (compared to 10 percent in distributed systems). And they are already being used by a number of different retailers in the U.S., including Target, Aldi, and H-E-B. But propane is also an A3 refrigerant, which means it is flammable. As such, technicians should obtain additional training and take special precautions when working with this refrigerant.
CO2 is less popular, as these refrigeration systems are more complex and expensive to install, but they, too, are gaining traction. Some contractors may be nervous about working with these systems, as CO2 is a much higher pressure refrigerant, so it is very important to make sure that tubing, valves, and all components are rated for use in a higher pressure application. Training for CO2 systems is often provided by the OEMs, which may also provide on-site support during installation.
The bottom line is that change is coming, and contractors and technicians need to educate themselves on all these new refrigerants. As Rajan Rajendran, vice president, systems innovation center and sustainability at Emerson noted at a recent webinar, the ubiquitous centralized refrigeration systems that utilize thousands of pounds of A1 refrigerant are probably going to become history.
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“When we start talking about lower-GWP refrigerants that are not A1, we start moving into the category of flammable refrigerants,” he said. “As we move into that area, some of these very large charge limits are no longer possible, so you are going to have to move into distributed architecture, remote condensing units, and self-contained equipment.”
That means the time to start learning about these new systems is now.
