Refrigerants Phase out to save our environment

Refrigerant Phase Out

What heat pump solution to consider into the future.

Refrigerants have been around for 100 years now. The early refrigerants worked incredibly well, but after intoxicating many people they realised that they had to invent non-toxic refrigerants and the first refrigerant phase out occurred.

Then came the 2nd Generation refrigerants, CFCs provided an excellent non-toxic solution, however, they began to realise the effects of CFCs on the Ozone layer. Chlorine and Bromine gases were a critical issue that had to be addressed. In 1987 the Montreal Protocol was developed on September 16th and a ban on all CFCs was launched along with a reduction of HCFCs, and the 2nd round of refrigerant phase out begun. This also was the beginning of the reduction of the famous R22 most of know about.

Scientists began to realised that Greenhouse Gasses contributed to global warming and also had to be addressed.  The Kyoto Protocol of 1997 addressed many of these issues and they identified many of today’s refrigerants are classified as greenhouse gasses and a key contributor to the latest refrigerant phase out.

When CFCs were banned two decades ago, the refrigerant phase out sparked concern about refrigerant cost, availability, and performance. As it turned out, the transition to the first generation of alternative refrigerants went off smoothly. And the phaseout of CFC refrigerants under the Montreal Protocol has helped the Antarctic ozone layer to begin to recover.

That first generation of alternative refrigerants after the 1st refrigerant phase out included HFCs (hydrofluorocarbons), which had no ozone depletion potential. But HFCs are potent greenhouse gases with high global warming potential (GWP) and long lifetimes. Now, they too face international refrigerant phase out by either hydrofluoroolefins (HFOs) or “natural” refrigerants under the October 2016 Kigali Amendment to the Montreal Protocol.

Although the United States has yet to officially embrace the Kigali Amendment, few experts doubt the science behind the global climate change actions of about 170 other nations.

Recognizing this concern, the Environmental Protection Agency (EPA) recently announced another refrigerant phase out to hydrofluorocarbons (HFCs), including those commonly used in commercial chillers.

Refrigerants affected

Among the HFCs and HFC-blend refrigerants affected by the regulations are several that are familiar to facility managers: R-404A, R-134a, and R-410A and R-407C, used to replace R-22.

Under the rules, new chillers would no longer be produced using these refrigerants after Jan. 1, 2024.

As well, HCFCs (hydrochlorofluorocarbons) were part of the refrigerant phase out when CFCs were being refrigerant phase outt. HCFCs had far lower ozone depletion potential than CFCs, but they were always seen as an interim solution because they contained ozone destroying chlorine.

Two HCFC refrigerants are widely used in commercial cooling: R-123 and R-22. R-123 will be part of the next refrigerant phase out for new HVAC equipment on Jan. 1, 2020; it will continue to be produced for servicing equipment until 2030. R-22 cannot currently be produced for use in new equipment; all production and import of new R-22 will end in 2020.

The change “does not impact any chillers sold before 2024 and does not impact servicing or maintenance,” says Jay A. Kohler, director of technology and innovation, chiller solutions, Johnson Controls.

“Existing equipment could continue to operate and be serviced with the refrigerant it is using,” explains EPA. The rule covers chillers; no status change was proposed for refrigerants used in other building HVAC systems.

HFCs have many good refrigerant properties. They meet the needs of the industry in terms of safety, reliability, efficiency, availability, and affordability, says Kohler. “They are non-ozone depleting, so there is no phase-out due to ozone depletion,” he says.

Unfortunately, they do have high GWP. “Many fluoridated gases have very high global warming potentials (GWPs) relative to other greenhouse gases, so small atmospheric concentration can have large effects on global temperatures,” explains EPA in its “Overview of Greenhouse Gases.”

EPA defines GWP as “a measure of the total energy that a gas absorbs over a particular period of time (usually 100 years).” Refrigerant HFCs can last up to 270 years in the atmosphere, according to EPA.

“For example, R-134a survives 14 years compared to R-1233zd(E), one of the new alternative refrigerants, at only 29 days,” explains Vijay Deshmukh, centrifugal chiller portfolio leader at Trane. “All chemicals have a finite life, but some are more stable than others. In general, the shorter the atmospheric life, the lower the environmental impact because the chemicals do not endure long in the atmosphere and have an impact.”

However, facility managers interested in protecting the environment with their selection of new HVAC equipment should not focus too strongly on the refrigerant’s GWP, cautions William Dietrich, product general manager for chillers with Daikin Applied.

“If the new refrigerant is less efficient than R134a or R410A,” Dietrich notes, “the chiller could lose efficiency and contribute more to global warming through higher energy usage leading to increased carbon emissions.”

As with any new technology, the next-generation refrigerants are more expensive than current refrigerants. But judging from past refrigerant transitions, that’s likely to change, says Deshmukh. “We can expect the current generation of HFCs to begin to become more expensive in the coming years, and the new HFO refrigerants to come down in price, as more factories are built and use spreads to more industries. This pricing shift in refrigerants could push the transition to next generation solutions ahead of current mandated phase out dates.”

Refrigerant Phase Out & The Transition to alternatives

EPA’s Significant New Alternatives Program (SNAP) reviews substitutes and their comparative risks for refrigeration and air conditioning, along with other industrial sectors, per Section 612 of the Clean Air Act. The SNAP list of approved refrigerants is not static. It changes as new refrigerant substitutes are developed and as knowledge about environmental and human health impacts evolves.

“SNAP also de-lists refrigerants,” Dietrich says. When a refrigerant is de-listed, as has already happened with R-22, it cannot be used in newly manufactured chillers after that date.  “There already are HFC compounds undergoing de-listing between 2019 and 2024 for different applications,” Dietrich says, and scheduled to be included in the refrigerant phase out process.

The development of new refrigerants and new chillers designed to use them is well underway. “Refrigerant manufacturers have started to develop alternative refrigerants,” says Kohler. “In some cases, they are commercially available for production, but at a cost. In other cases, they have been made available for test, but are not in full production.”

Although some alternatives to HFC are already available, offering equal or better refrigerant efficiencies and with less impact on GWP, research continues, says Karim Amrane, senior vice president of regulatory and research with the Air-Conditioning, Heating and Refrigeration Institute (AHRI).

“In order to reduce GWP, the molecule being used has to be unstable and break down rapidly if it should be released into the air,” Amrane explains. “The problem is that an unstable molecule is highly or mildly flammable, most of the time. One exception is carbon dioxide, which is not flammable.”

The experts seem to agree that facility managers do not need to worry about this latest refrigerant transition happening overnight. “The HVAC industry has worked very closely with the EPA to ensure than the phase down timelines allow an appropriate amount of time for manufacturers to develop products with next generation solutions,” says Deshmukh.

The next-generation refrigerants basically fall into two categories. The first are chemically produced and are mainly hydrofluoroolefins (HFOs) or blends of HFCs and HFOs.

“New refrigerant technology is developing rapidly,” says Deshmukh. Among HFOs are R-1233zd(E), R-1234yf, R-1234ze, R-1336 mzz(Z), R-513A, R-514A, R-452B and R-454B.

Several HFOs already available in new chillers have many of the attributes of R-134a and R-410A. They have low toxicity and low flammability, and are classified by ASHRAE as A1 refrigerants. The A1 classification means they do not need to wait for new model codes and standards revisions for installation and operation, explains Dietrich.

R-513A is a blend of HFC-134a and HFO-1234yf. “R-513A is a non-flammable refrigerant that has a lower GWP than R-134a, but similar performance,” says Kohler. The blend has low toxicity and flammability, along with a 56 percent reduction in GWP, according to Deshmukh.

R-1233zd(E) is a single component refrigerant that has low toxicity, is nonflammable, and also has a low GWP. While R-1223zd(E) is an alternative for new chillers, it is not a retrofit alternative for existing R-123 chillers.

One retrofit alternative for R-123 is R-514A, although the chiller will have to undergo some modifications to use it. Like R-123, R-514A has an ASHRAE B designation because of its higher toxicity and currently it may reduce the capacity of an R-123 machine. R-514A also is being offered as an option in some new water-cooled centrifugal chillers.Natural refrigerants

In addition to the chemically produced HFOs, chiller manufacturers also are using natural refrigerants, which are substances “that exist naturally in the environment and can be used as cooling mediums in refrigeration systems,” according to Michel Moreira, commercial refrigeration sales senior manager with Embraco, North America region.

Commonly used natural refrigerants include hydrocarbons such as butane and propane, carbon dioxide, and ammonia. “The use of natural refrigerants has been successful in many developed countries and it is on the agenda worldwide,” says Moreira.

The reason for the growing popularity of natural refrigerants is that they have very low GWP compared to most HFCs. “For example, R-290 (propane) and R-600a (isobutene) have a GWP of 3.” This is significantly lower than R-134a (1,430) and R-404A (3,922). Carbon dioxide has a GWP of 1.

One potential drawback of natural refrigerants is that, with the exception of carbon dioxide, they are more flammable and can be more toxic than refrigerants currently being used.

The HVAC industry, ASHRAE, and life safety and building codes groups are investigating the safety of flammable refrigerants and determining the risks, probabilities of occurrence, and potential severity for various next-gen refrigerant applications. Several safety codes, including the National Fire Protection Association (NFPA) and ASHRAE 15, govern commercial and institutional HVAC systems.

The industry is currently working on a new 2L sub-classification for refrigerant flammability to cover “mildly flammable” refrigerants.

“ASHRAE 15 does not really address the new category of mildly flammable refrigerants,” says Amrane. “So ASHRAE is revising the standard and proposals are being debated.” According to Amrane, the revised ASHRAE 15 standard may be completed by early 2018. When that is accomplished, the revised safety standard will be incorporated into the International Fire Code and mechanical codes, he says.

Once the codes and standards are in place, they still require adoption by states and local building and fire codes.

“In cases where the new refrigerant falls under the ASHRAE 2L flammability safety group, the product safety codes and building codes in the United States are not yet in place to allow use of these refrigerants at all,” notes Kohler.

Like their chemical counterparts, natural refrigerants are now being used by chiller manufacturers. To ensure the installed chillers meet evolving rules and regulations, Moreira emphasizes the importance of training both manufacturers and service technicians so that natural refrigerants are properly handled.

Managing leaks

The Environmental Protection Agency has taken steps to reduce leaks of refrigerants. Now, all refrigerant replacement substances, including HFCs and HFO options, are covered by containment requirements, not just CFCs and HCFCs as was previously the case. “Hydrocarbons in small, self-contained systems are given an exception for venting,” says Vijay Deshmukh, centrifugal chiller portfolio leader at Trane.

Annual trigger leak rates, which require facility managers to take corrective action, have been reduced as well. For example, the new trigger leak rate for comfort cooling has been reduced from 15 percent to 10 percent. Deshmukh believes this may push or encourage the HVAC industry to move toward technologies that are more hermetic with fewer joints and seals, “for better long-term refrigerant containment.”

The new rule also has mandatory leak inspections requirements and increased recordkeeping requirements.

The changes to refrigerant management requirements under Section 608 of the Clean Air Act were effective Jan. 1, 2017 and will be fully implemented by Jan. 1, 2019, according to Deshmukh.

Balancing act

Because many refrigerant changes are still a few years away, experts are not anticipating any major disruptions in terms of supply of the next or the last generation of refrigerants for the near future.

Meanwhile, facility managers are faced with a delicate balancing act when it comes to deciding on new chiller purchases and future refrigerant needs. Refrigerant selection still must weigh building occupant safety, energy efficiency, initial costs, lifecycle maintenance and operations costs, and refrigerant and chiller sustainability.

Despite some questions, the transition to new alternative refrigerants could yield a bonus: Next-generation refrigerants may improve energy efficiency substantially.

“R-410A replacements are currently being developed which could see significant efficiency improvements,” observes Deshmukh. “For large tonnage centrifugal chillers, we are seeing the industry looking toward more efficient low pressure solutions that are better in efficiency than medium pressure R-134a.”

Rita Tatum, a contributing editor for Building Operating Management, has more than 25 years of experience covering facility design and technology.

Email comments and questions to edward.sullivan@tradepress.com.

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