As we reach the midpoint of a sweltering summer, maintaining refrigerated environments is more crucial than ever. It takes an entire industry of stakeholders to ensure the cold chain is reliable, but reliability is only part of the equation. Sustainability is now a driving force throughout all facets of the refrigeration industry. Our refrigeration experts are actively involved in the effort to move towards our MEP 2040 commitments and refrigerants have one of the largest impacts in achieving that goal. We work with people throughout the industry who are passionate about making positive changes and reducing the impact of the cold chain along the way.
The Refrigeration industry has been notoriously cautious and slow to adopt innovative technologies, but this decade is primed to experience more growth than the past three decades combined. The evolving landscape of natural refrigeration technologies coupled with progressive policy adoption and climate commitments from the largest grocery retailers will lead to exponential change.
Henderson Engineers recently attended the 2023 ATMOsphere America Summit in Washington, D.C. The annual event provides attendees with insight into the future of natural refrigerant-based technologies, allows for cross functional knowledge sharing among industry peers, and offers presentations ranging from end user sustainable system installation examples to regulatory updates and non-profit involvement. Refrigeration technical managers Jason Cornett, Conner Meadows, and Lidia Leon Perez along with Dustin Padget, practice manager, returned from the event with the following key takeaways:
Regulatory 101
The refrigeration industry is seeing significant regulatory changes with a strong focus on lowering the environmental impact of systems, increasing the energy efficiency of systems, and adopting alternative refrigerants. Regulations are a hot topic within the refrigeration industry and with no doubt will continue to be. The EPA (Environmental Protection Agency) operates the Significant New Alternatives Policy (SNAP) Program to minimize the impact of refrigerants on the environment. This is done partly by reducing the use of high Global Warming Potential (GWP) refrigerants. Some recent and notable regulatory trends include:
Three-Legged-Stool
The EPA explained how the AIM Act gives them authority to regulate HFC refrigerants as a class and how it does this via their “three-legged-stool.” The three legs consist of mandates for the phasedown of HFCs (restrict supply), allowances for sector-based transitions to lower-GWP alternatives in new equipment (reduce demand), and the authority for the EPA to establish HFC management via service, repair, recovery, reclamation, and recycling (oversee HFC management).
Apart from their contribution to global warming, high GWP refrigerants are now part of an important discussion concerning the regulation of PFAS, a broad group encompassing over 9,000 different chemicals. Certain synthetic refrigerants, notably specific HFO (hydrofluoroolefin) blends and HFC components, contain short-chain carbon/fluorine bonds like CF3. When released into the atmosphere, these refrigerants can degrade into a substance known as Trifluoroacetic Acid (TFA). As such, there are ongoing efforts to determine whether some synthetic refrigerants should be classified as PFAS. This dialogue, in which various industry stakeholders play a significant role, is likely to shape the future of synthetic refrigerants in the coming years, as has happened before with CFC (chlorofluorocarbons) and HFC regulations.
PFAS Will be the next phasedown (Plan Now)
PFAS are synthetic chemicals subject to active regulation in Europe and Canada, and similar regulations are being considered in the U.S. Their pervasive presence in water, soil, and air has raised questions about their potential effects on human health and the environment. A key issue with PFAS is their environmental persistence and their tendency to accumulate in the human body over time. Addressing these potential health risks, the EPA and several states are contemplating restrictions on the use of specific PFAS in certain products and sectors, with exemptions for industries without viable alternatives.
Industry Efforts Combined
Organizations like NASRC (North American Sustainable Refrigeration Council), ATMO, ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers), IIAR (International Institute of Ammonia Refrigeration), EPA, and RETA (The Refrigerating Engineers & Technicians Association) are actively engaged within their circle of influence towards lowering the barriers to adoption for sustainable refrigerant solutions, including natural refrigerants. Their efforts cover multiple perspectives that the industry relies on including networking, resources, knowledge sharing, incentives, technical training, standards, code adoption, regulations, and certifications. Each organization has a critical role to play within the refrigeration industry, but the largest burden is carried by the grocery end user as the expenses incurred by changes to regulations will be realized by them.
One of our industry’s biggest hurdles to overcome this decade is how to transition the thousands of existing grocery store refrigeration systems from synthetic high GWP refrigerants to systems with minimal global warming impact and ideally a natural refrigerant solution. This is not as simple as replacing the refrigerant with one that has less impact. The industry has already been through this method of incremental improvement when transitioning from CFCs to HFCs. Most grocery stores are not able to absorb any downtime with their refrigeration system, so full equipment replacement requires attention to detail, communication with all stakeholders, specific coordination, and phasing plans to avoid any loss of refrigeration during the project.
Retailers have an urgent need to evaluate refrigerant options to understand what’s best for refrigeration equipment and assess the risks. End users need to analyze current facilities to see if new refrigerants can be incorporated, figure out how to update current refrigeration systems, and work with manufacturers, design engineers, equipment suppliers, and other vendors to source materials. It is critical for end users to work as a team with manufacturers and contractors to test new units and evaluate their performance and environmental impact. By leveraging the industry’s shared experience, an end user can ease their burden of sustainable refrigerant technologies. Involvement in organizations is key to this support. The refrigeration industry in the U.S. is dramatically evolving and attracting European manufacturers that have years of experience with natural refrigerants. There’s an unlimited potential and market in the U.S. in the immediate future as the voices of environmental protection are rising.
What are Our Options?
Refrigerant grade carbon dioxide (R744 (CO2)) is the most popular natural refrigerant in commercial refrigeration because of its low GWP of 1 and the fact that it is non-toxic and inexpensive. From the perspective of thermodynamics, CO2 has a high specific heat, high thermal conductivity, and low kinematic viscosity, which gives it a high heat transfer efficiency. Since GWP is based on CO2 (as the denominator in the GWP equation), it is what all other refrigerants are compared to. CO2 has one of the lowest ODP (Ozone Depletion) and GWP, which are respectively 0 and 1. R744 is classified as an “A1” safety group meaning it is non-toxic and nonflammable as a natural working fluid, making it a very safe substance.
The next group of natural refrigerants that will see wider adoption in micro-distributed and self-contained applications are Hydrocarbons, most commonly R-290 (Propane) and R-600 (Isobutane). Although they have a cost prohibitive charge limit (150g), progress has been made to increase it (300-500g) to allow for fewer units per foot of refrigerated merchandiser. Ideally, case manufacturers could include 1 condensing unit per 12’ of merchandise case, but the 150g (about half the weight of a can of soup) charge limit typically results in 1 unit per 3’ of refrigerated merchandise case. ASHRAE safety standards have been updated to include information on safe quantities of A2L refrigerants and increases to the allowable charge of A3 refrigerants like propane and isobutane, but model codes are still working to adopt the updated standards. This information is included in ASHRAE 15 4L2-40 and 2-89 which was approved in August of 2022 by ASHRAE and the American National Standards Institute (ANSI).
Another viable option for end users, although limited in application in grocery, is NH3 (ammonia). There has been an increased investment by manufacturers to include low-charge NH3 packaged equipment to keep the ammonia out of the store and avoid the strict regulations around it as a substance. The International Institute of Ammonia Refrigeration (IIAR) is the trusted authority in the industry and their ANSI standards for NH3 and CO2 will be directly included in all model codes (IFC, IMC, NFPA (National Fire Protection Association) 1 Fire Code NFPA 70 NEC (National Electrical Code), UMC, etc.) in the 2024 code cycle. This is a good step for the industry as it aligns the standards with the model codes, so they can then be adopted codes.
Considerations with CO2
There are some limitations to design around when using CO2 as a refrigerant, specifically due to its low critical temperature (87.8 degrees Fahrenheit) and high critical pressure (74bar /1071 psia). Operating above this temperature requires the use of stainless steel or copper iron alloy on the “high” side of the system and often the need for an adiabatic condenser. When operating as a supercritical fluid often referred to as “transcritical” operation, there is also a loss in efficiency that results in more energy used by the compressor(s) and gas cooler fans, since a portion of the CO2 refrigerant will not condense or do any “work” refrigeration.
Informed end users see the value in adopting higher standstill pressures to keep more of the CO2 inside the system by designing equipment rated for 60, 90 or 120 bar standstill pressures. This allows the systems to go longer without the need to relieve pressure, especially during a power failure. The design of these systems can be complicated from an outsider’s perspective, but our team of experienced design professionals will help simplify the design and work with all the project stakeholders to produce the best solution for each unique site. Our experts are familiar with natural refrigerant solutions and have designed over 80 projects with CO2 as the primary refrigerant within the past couple of years.
The need for a better solution to the widespread practice of venting CO2 into the atmosphere was discussed, but there are currently no commercial options other than increasing the standstill pressure rating of a system to passively maintain refrigerant charge during a power outage in high ambient conditions. Attendees recognized the importance of implementing recovery systems instead, emphasizing the industry’s commitment to environmental sustainability.
Manufacturer Innovation Needs to be Standardized
The energy consumption of a refrigeration system is a key factor when evaluating its total cost of ownership. For a CO2 refrigeration system, energy efficiency is highly dependent on the ambient conditions. The goal of improving system energy efficiencies in warmer climates has become a major focus area for equipment manufacturers. Leading system design optimization strategies typically include added cost. If end users are expected to adopt these technologies, the manufacturers will need to do a better job of explaining the benefits and calculating the return on investment (ROI) for each expenditure. Until these technologies are included as the standard, they will be looked at as unnecessary by the cost conscience grocery store owner. Some of these technologies include:
With these innovative technologies comes the need for more robust controls and monitoring systems. The installing contractor and equipment operators are vital to maintaining the new equipment. Clearly identified sequence of operations written in plain language with visual examples will be key to the success of new equipment.
Refrigeration Commissioning Benefits and Statistics
While installation is critical to the operation of every system it is also equally important to ensure that the system has been commissioned. One of the key highlights from ATMOsphere America Summit 2023 was the emphasis on the benefits of refrigeration commissioning. This process, which involves optimizing the performance of refrigeration systems, offers several advantages for the industry. Attendees learned that proper commissioning implementation can result in improved energy efficiency, reduced operating costs, and enhanced system reliability. Notably, statistics presented during the conference indicated that businesses that implemented refrigeration commissioning experienced an average energy savings of 15-30% compared to non-commissioned systems.
The refrigeration industry is expected to undergo significant transformations in the U.S. over the next several years. We will witness several technologies and refrigerants emerge with the goal to create refrigeration systems that enable food retailers to meet their sustainability goals and comply with environmental regulations.
The Crystal Ball: Actionable Strategies for the Future
The refrigeration industry is entering a period of major change. It is essential for all stakeholders to actively engage with these developments. Below is a breakdown of concrete steps and strategies for different stakeholders:
For Businesses
For Policymakers
For the Industry as a Whole
Practical Outlook
As the refrigeration industry evolves, it’s important that all stakeholders take practical and proactive steps to not only comply with regulations but also to contribute to environmental sustainability. Through collaboration, continuous improvement, and a commitment to environmental responsibility, the industry can thrive while also having a positive impact on the world.
Henderson Knows Sustainable Refrigeration
With more than 50+ years of experience in refrigeration design across retail, grocery stores, cold storage, and distribution centers, we’ve worked on every facility type and size. We understand how refrigerants align with corporate sustainability goals, and we constantly monitor the evolving regulatory landscape. We’re currently working with seven of the 10 biggest retailers/grocers in the world to help with their climate pledge goals. Click here to learn more.
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