Ammonia refrigeration systems are becoming more compact, portable and simpler to install, widening the potential for adoption of ammonia, carbon dioxide and other natural refrigerants in previously untapped industries.

The evolution of low-charge and package ammonia systems, which means they no longer require a complex installation for some end-user facilities, comes as users are dealing with the phase-out of R-22 and other hydrofluorocarbon refrigerants to comply with Environmental Protection Agency requirements.

“Natural refrigerants don’t harm the environment, they help operators meet their regulatory requirements and operators don’t have to be concerned in the long run with refrigerant phase-outs from regulatory agencies, such as EPA,” said Dave Rule, president of IIAR.

If operators switch to a synthetic refrigerant and then it turns out there is a new environmental concern, then they must switch to another refrigerant product. Some concerns with newer synthetics include increased flammability, potential global warming issues and cost.

Today, companies in the retail food industry, such as operators of microbreweries, small cold-storage facilities and supermarkets, have the option of using small, manufactured package systems that can be operated with very low charges of ammonia in conjunction with CO2 .

“That means they’re using a smallcharge ammonia package on the roof, so it is isolated from the public. Then they’re putting a secondary coolant circuit that is doing the cooling inside the building. Typically, that circuit would hold a CO2 refrigerant or brine,” Rule said, adding that ammonia wouldn’t be used inside the retail environment. These systems can be very economical to operate.

While some grocery stores have utilized ammonia-CO2 systems, Rule said many people have concerns over ammonia because they don’t understand it. “These systems have been tried and they’ve been used very effectively, but a lot of supermarkets are going to a straight CO2 transcritical system,” he said. The refrigerant phaseout issues are being addressed but operating costs may prove to be an issue with CO2 transcritical designs.


Although some retail facilities have been experimenting with ammonia lowcharge systems, the commercial market still has not be proven out. There are numerous hurdles to clear before grocery chains jump in with both feet.

Morgan Smith, project manager for the North American Sustainable Refrigeration Council, which is based in Mill Valley, California, said hurdles that need to be cleared before the retail supermarket industry commits itself include potential high initial costs, availability of trained contractors and service technicians, and appropriate regulatory guidance for ammonia in the commercial sector.

Caleb Nelson, vice president of business development for Azane Inc., agreed that for ammonia to become more widely adopted by retailers, initial capital costs will need to come down. That is not because of high total cost of ownership but because project budgets are often tight and require the lowest bidders to be selected.

Kurt Liebendorfer, vice president of Evapco, based in Taneytown, Maryland, said he has heard that retailers such as grocery stores are less likely to invest in a costly conversion because the locations may move or close. “I’m sure it varies by the particular grocery chain you’re speaking to. Some are more sustainable looking forward and others are less so,” he said, adding that it becomes less of an issue higher up the food distribution chain.

Although the purchase and installation costs have been higher, that is changing very quickly. “In the past, they’ve been custom-designed, built-up systems. As manufacturers develop packaged products that can be built in, quality and installing contractors become familiar with the systems, so the cost will come down dramatically,” Rule said.

Nelson agreed that volume and economies of scale will help bring down costs but said initial costs will likely never be on par with an HFC system due to inherent differences, which affect quality, lifespan, efficiency and reliability. “You get what you pay for and you should get the best of all those with an ammonia system done right,” he said.

“I think the temptation is to try to build ammonia cheaply, but from what I’ve seen this will actually have a negative effect on total cost of ownership, because by making things cheaper, you’re probably making the system less reliable, and more importantly, less efficient,” Nelson said.

Randy Fernandez, national sales manager for Kysor Warren, based in Columbus, Georgia, said there is a trend among some grocers who are seeking low quality, short-term capital investments, but he doesn’t think that is widespread. “I think most understand the value of sound capital investments that have terrific quality, produce results and offer a solid fit to operational strategies,” he said.

A compelling story coupled with solid proof that demonstrates the value of the investment in natural refrigerants will help spur adoption, Fernandez said. “Every customer is going to be seeking a different set of benefits and we need to shape the messaging accordingly as low-charge systems really yield a great number of benefits,” he said. Information on the benefits, training and installation, ease of adoption, return on investment and energy savings will all factor into users’ decision-making process, he added.

Rule said the payback on lower energy costs should be very good, benefiting businesses such as the grocery industry, where operating costs are a significant concern.

“All of our life-cycle costing models show that efficiency — not the rated efficiency but the efficiency the system is likely to actually maintain for the life of the system — is the most important metric for payback and favorable total cost of ownership. So, if you focus too much on first costs, you’re also giving away some of the benefits you’re paying extra for. It’s a bit of a Catch 22,” Nelson said.

What’s more, maintenance costs of natural refrigerants shouldn’t be much higher, if they are at all, than HFC systems because they are more robust and easier to operate. Nelson said operators should consider other factors, such as the typical HFC refrigerant replacement expense cost of downtime or loss of revenue.

Nelson said our products can show a payback advantage over HFC systems in the four-to-seven-year range. “I think there are end users that are focused on life-cycle costs and are ready to invest in good longterm business decisions. Of course, utility incentives for efficient technology will help, and there’s even some incentives available now for natural refrigerants due to the focus on greenhouse gas reductions in certain parts of the country,” he said.

Nelson said ammonia could give retailers a standard design that is repeatable and efficient in any climate because ammonia isn’t penalized like CO2 is in warmer climates. “Furthermore, the same ammonia system cooling the high side of a CO2 system, for example, can also provide air-conditioning and building heat to offer a 100 percent natural refrigeration solution for the entire building,” he said.

That would mean the central cooling/ heating part of the system would be set up for long-term efficient operation and would be immune to the ever-changing politics and regulation that affect synthetic refrigerants, Nelson explained. He added that retailers, even the ones with very exotic natural systems for refrigeration, have struggled to figure out a natural refrigerant solution for their HVAC systems. “A central ammonia chiller providing refrigeration could easily do both.”

CO2 systems are more efficient in cold climates, and in some regions, operators must run on a transcritical system during certain times of the year. “If you’re operating a supermarket in northern Vermont where you don’t get the high temperatures in the summertime, then the CO2 system is reasonably efficient. As you go further south, they become more difficult to operate and maintain,” Rule said, adding that ammonia with CO2 can operate much more efficiently and save operators money on energy costs. “By lowering the energy demand, it is a secondary benefit to the environment because the additional electrical burden you put on the grid is normally a negative impact on the environment.”

Fernandez said Kysor Warren’s installation at a 40,000-square-foot Piggly Wiggly store in Georgia had an overall energy savings of 22 percent, using a 53-pound charge of ammonia.

Efficiency can vary based on how many bells and whistles the CO2 system is fitted with to regain the efficiency losses of supercritical operation in hot ambienttemperature situations. “However, a CO2 booster transcritical system with parallel compression in a moderate climate should at least be able to be on par with a R407a/ CO2 cascade system. And I know of at least two retail case studies of ammonia system operating 20-25 percent better than a R407a/CO2 system,” Nelson said.


Ammonia is a highly regulated refrigerant by both the Occupational Safety and Health Administration and the Environmental Protection Agency. Systems that use 10,000 pounds of ammonia or more are ruled by the PSM/RMP program, which has strict guidelines and reporting systems. Systems below 10,000 pounds, which is still well above the amount that would be used in the commercial and retail industry, must adhere to OSHA’s General Duty Clause, Rule said.

Several years ago, IIAR developed the Ammonia Resource Management (ARM) manual to give guidance for complying with the General Duty Clause. “Now we have the commercial industry — light industrial, small cold-storage facilities and the retail food industry — that has an opportunity to use ammonia systems in their facilities, but they don’t have a business model where they have engineers and technicians on-site,” Rule said.

That creates a dilemma, he said. “The regulators are questioning proper guidance and monitoring for these systems. The owners and the rest of the commercial industry are doing the same thing.”

To provide guidance, IIAR has developed the ARM-Low-Charge guidelines, also called ARM-LC, which is slated to be published in the next few months. It will help those in the food and retail distribution space create a refrigeration management program to ensure they meet the General Duty Clause and operate their systems safely. “If your refrigeration management program is effectively set up, your regulatory burden to manage it shouldn’t be higher than it was on HFC systems,” Rule said.

IIAR is also developing the ARM-LC Reference Manual, which provides specific details on what the design engineer, equipment manufacturer and installing contractor should look for and be aware of. “It simplifies what operators need to be doing to properly document and set up their refrigeration management program so they’re compliant.”

“Some consider this to be very onerous and difficult when it really isn’t,” Rule said. “It is more a system of documenting your program and how you select your equipment and contractor and set up the management system.”

The program is very similar to current requirements for operating a store with today’s HFC refrigerants. “Although they’re not dealing with toxic refrigerants, there are still safety procedures, leak-reporting requirements and emergency management systems, so the concept of having a refrigeration management system should already be in place. This just gives you another way to look at it,” Rule said.

Nelson said it may be only the biggest retailers that develop formal management systems and execute them in a consistent manner. “Actually, many large retailers are already familiar with General Duty Clause compliance, or even PSM/RMP compliance where they have ammonia distribution centers already. The smaller users that choose ammonia will deal with it on a case-by-case basis.”

Tony Lundell, director of standards and safety for IIAR, said as a best practice, each refrigeration system should have its own Recognized and Generally Accepted Good Engineering Practices file, even if they aren’t required to, because they’re under 10,000 pounds. He said operators should have a file for each refrigeration system they have on-site detailing how the system was designed and installed and how it is continuously maintained for safe operations. “If an inspector from EPA or OSHA looks at the system, they can only audit against those files,” he said.

If a system is under 10,000 pounds, an operator can’t be audited under PSM, but an inspector can ask to see information under the General Duty Clause. It is very generalized and they’ll start asking for system information.

“The ARM-LC document was developed to provide proper guidance for the owner and their service contractor to address these issues,” Lundell said.

Nelson said some HFC requirements, such as those in California, are more burdensome than those for natural refrigerants. “Many don’t realize that HFCs have been regulated there ever since 2006 with rules similar to the EPA’s regulation of R-22 through Section 608 of the Clean Air Act, which, by the way, has resulted in many large fines issued to end users over the years, some well over $500,000,” he said.

The federal EPA has recently made these regulations applicable for HFCs also, and has made the use of several HFC refrigerants illegal for use in certain applications through the federal Clean Air Act’s Significant New Alternatives Policy program. “While this is all still tied up in legal battles on the federal level, California has gone ahead and adopted them locally,” Nelson said. “So, with California being the largest U.S. economy, I would expect to see a continued trend toward more federal regulation for HFCs in the U.S., if not in the current administration, likely in the next.”


In addition to the potential growth in the grocery industry, Liebendorfer said he also sees tremendous opportunities one tier up from the supermarkets, in the distribution centers and warehouses that serve the retail-food segment of the industry. The many smaller distribution centers, food-service providers and fulfillment centers have historically utilized Freon and present an immediate opportunity for ammonia, particularly because they’re so focused on energy savings. “There is an uptick in smaller cold storage facilities and this is where ammonia and ammonia CO2 will be experiencing rapid growth in the next few months,” Liebendorfer said.

No matter what segment of the industry is adopting natural refrigerants, ammonia systems can offer significant benefits, including no global warming potential, a future-proof refrigerant and excellent thermodynamic qualities, Fernandez said. “When combined with a CO2 system there is even improvement (reduction) in pulldown time at the case level,” he added.

Awareness and education will continue to drive the future for natural refrigerants. “It is time to band together as stakeholders to drive the change we are seeking. It will be a win-win for all in the long run,” Fernandez said.