True Begins Rolling out R290 Refrigerant Technology
True Refrigeration, an industry leader in restaurant refrigeration solutions from reach ins to prep tables, has made a change that will eventually affect their entire line of equipment. This change is intended to help protect the environment and save operators money on the lifetime cost of ownership of True equipment.
True began rolling out the new models one by one in spring 2015, with plans in place to complete the rollout by 2017. This updated equipment uses a cutting-edge hydrocarbon (HC) refrigerant to replace R-134a and R-404a in the company's refrigerators and freezers, respectively. This change is meant to address growing concerns over those chemicals' potential to contribute to global warming, but they also bring with them several advantages that mean lower operating costs for the end user.
True decided to make this change to address scientific findings that confirm that R-134a and R-404a refrigerants, which are considered greenhouse gases, can contribute to global warming. Their efforts are the first in a new chapter of the long story of changing refrigeration standards. Readers may remember the shift from chlorofluorocarbons (CFCs), including the popular R-12 and R-22 blends, which had been used as the primary refrigerant in commercial units from the 1920s until the late 1980s.
It was during the 80s that researchers made the finding that CFCs - specifically the rogue chlorine atom that is created when the compounds are broken down in the atmosphere - were depleting Earth's ozone layer. That layer of oxygen high above the Earth's surface is critical to protecting life on Earth from the sun's harmful UV radiation. Scientists, activists, and legislators began working to ban the use of CFCs, and in 1987, the Montreal Protocol banned CFCs in a number of countries, including the United States.1
The refrigerants that came to replace CFCs are members of a similar group of compounds, HFCs (hydrofluorocarbons). Including R-134a and R-404a, those chemicals have served as alternatives to CFCs in virtually all foodservice refrigeration equipment until now. Their lack of a chlorine molecule means that they have 0 ozone depletion potential, and the fact that they are non-toxic and non-flammable means that they don't carry any direct health concerns, either. The problem with HFC refrigerants, however, is that they are greenhouse gases. That means that if they're allowed to be released into the atmosphere, they can contribute to global warming in much the same way that CO2 from the combustion of fossil fuel does, except HFCs have global warming potential in the range of hundreds to thousands of times greater than that of carbon dioxide due to their longer life spans in the atmosphere.2
The R290 refrigerant chosen to replace HFCs is simply a highly-refined blend of propane, an abundant, non-toxic, and naturally-occurring compound that most people associate as a fossil fuel. As a matter of fact, propane has properties similar to popular, man-made refrigerants. The substance has long been used as a refrigerant in industrial and commercial applications, but as foodservice equipment companies including True sought an alternative to synthetic refrigerants, whether R290 was a viable alternative to HFCs was a question that received much debate. Numerous studies, including one3 published in the International Journal of Current Engineering and Technology showed R290 and HFCs have very similar thermodynamic properties, meaning that they absorb and transfer heat in much the same way. A white paper, based on the actual production experience4of a major compressor company names R290 as the best alternative to traditional refrigerants.
Another major concern was whether existing commercial refrigerators could be redesigned to safely and efficiently use R290 without increasing the cost of the equipment to the consumer and without requiring an unreasonable amount of time and cost to make the necessary adjustments. That question was at the center of a study published5 in a 2013 Volume of Renewable and Sustainable Energy Reviews, which found that hydrocarbons are the "most suitable long-term alternatives in refrigeration…" and that "natural refrigerants, especially hydrocarbons and their mixtures are miscible with both mineral oil…" and "fully compatible with all materials traditionally used in refrigeration systems." Those findings affirm that R290 can be used safely with current refrigeration technology without the need for costly overhauls.
Hydrocarbon Refrigerant Means More Efficient Equipment
As it happens, R290 refrigerant isn't just an environmentally-sound replacement to HFCs, its use also results in energy savings. Several studies have confirmed this, including a study 6 finding a 28.5 percent increase in efficiency for domestic refrigeration. A study7 published in 2014 supported these findings, showing that a freezer with R290 was 28 percent more energy efficient than it was using R134a, and a report8 issued by the European Initiative for Natural Refrigerants, states that certain hydrocarbon drink chillers were 27 percent more energy efficient than the same units using R134a refrigerant.
Mitigating the Fears that Propane Refrigerant Poses a Risk of Explosion
The fact that propane is combustible and is widely used as a fuel has raised concerns of whether it's safe to use as a refrigerant. Many have wondered if leaks in the system could pose an explosion risk, especially in kitchens that cook with open gas flames. A study9 designed to determine just that, published in 2013 in the International Journal of Refrigeration, measured the risk of a fire posed by the use of ice cream freezers using R290. The study found that the chance of ignition is less than 0.001 percent.
Another study of more than 2 million ice cream freezers being used in the field10confirmed that equipment using R290 show no change in safety, reliability, or performance over traditional equipment. Contributing to this low risk is the relatively small volume of propane actually needed to act as a refrigerant in these machines, which, in some cases, is less than half that required in HFC equipment to achieve the same levels of performance.11 That lower volume also means lower pressures inside the system, and can also bring a reduction in noise, as well as the wear and tear on refrigeration components.
More than 1.5 billion HC refrigerators and freezers are already being used in homes worldwide, and they've been used in Europe for more than 20 years. The Environmental Protection Agency approved its use in the US in 2011, and there are UL and ANSI/ASHRAE standards in place to regulate its use in commercial foodservice equipment. The adoption of hydrocarbon refrigerant also helps companies prepare for tightening energy-efficiency requirements that will soon be phased in by the Department of Energy.
True Refrigeration spent four years engineering their HC models before releasing them for sale, ensuring that each one is built to safely and efficiently use the new refrigerant. The redesigned models will feature faster pull-down times due to propane's quick heat absorption. The new units are also predicted to last longer because the lower pressure in the system versus traditional systems means less wear and tear. These features are all being made available with no price increase.
1. U.S. National Library of Medicine: Tox Town; What are Chlorofluorocarbons (CFCs)?
2, 11. Kauffeld, Machael. Environmental Investigation Agency. Availability of low GWP alternatives to HFCs.
3. Roy, Randera and Bijan Kumar Mandal. First Law and Second Law Analysis of Mechanical Vapour Compression Refrigeration System using Refrigerants CFC12, R134a, and R290.
4. Jurgensen, Heinz. Danfoss Compressors GmbH. Propane as R22-Replacement in Commercial Applications.
5. Bolaji, B. O., and Z. Huan. Renewable and Sustainable Energy Reviews, Volume 18, February 2013, Pages 49-54. Ozone depletion and global warning: Case for the use of natural refrigerant - a review.
6. Saravanakumar, R. and V. Selladurai.Journal of Thermal Analysis and Calorimetry. January 2014, Volume 115, Issue 1, Pages 933-940. Exergy analysis of a domestic refrigerator using eco-friendly R290/R600a refrigerant mixture as an alternative to R134a.
7. He, Mao-Gang, Xin-Zhou Song, Huan Liu, and Ying Zhang. Application of natural refrigerant propane and propane/isobutene in large capacity chest freezer. Applied Thermal Energy. Volume 70, Issue 1, 5 September 2014, pages 732-736.
8. Witt, Monika. Natural refrigerants: current developments and trends. Euramomon.
9. Colbourne, D. and L. Espersen. International Journal of Refrigeration. Volume 36, Issue 4, June 2013, pages 1208-1219. Quantitative risk assessment of R290 in ice cream cabinets.
10. Van Gerwin, Rene, Alan Gerrand, and Fabio Roberti. Ice Cream Cabinets Using a Hydrocarbon Refrigerant: From Technology Concept to Global Rollout.