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By Alexander Ing, NFPA associate engineer

In 2016, nearly 200 countries signed the Kigali Agreement, a legally binding accord focused on the reduction of hydrofluorocarbons (HFCs) - the hydrogen, carbon, fluorine based compound that is commonly used in refrigerators and air conditioners. The agreement went into effect in January of this year.

Reduction efforts aim to limit the rise in global warming by less than 2 degrees Celsius by the end of the 21st century. HFCs, while small in overall volume compared to other greenhouse gases such as carbon dioxide, have greater heat-trapping characteristics than that of other greenhouse gases. These heat-trapping characteristics have made them an ideal refrigerant choice (the substance that circulates through cooling systems to absorb heat and chill the air) because of their efficiency, and low toxicity and flammability.

With the signing of the Kigali Agreement, countries around the world have begun to phase out HFCs, and to consider alternative replacements. The challenge is that there is no easy way to go about replacing these systems with an ideal combination of efficiency, low toxicity, and flammability. Until this ideal solution is found, one or more of these characteristics will have to be sacrificed. For example ammonia, which is both flammable and toxic, could be used as a replacement for some systems, however its flammability and toxicity as well as its efficiency, relegates its use to outdoor, rooftop systems. A more common tradeoff, however, is to use non-toxic but still flammable refrigerants.

The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) maintains a safety rating system for refrigerants that scores each refrigerant in relationship to its flammability and toxicity. Non-toxic refrigerants are class A and toxic refrigerants are class B. Following their toxicity will be a number indicating their level of flammability on a scale of 1-3 with 1 being nonflammable and 3 being the most flammable.

One class A3 HFC refrigerant replacement is R-290 Propane. While slightly different than your household BBQ-grill-variety propane (e.g., R-290 is unodorized), composition-wise it is the same. A way to look at the amount of R-290 in a refrigeration system is to compare that to propane in a storage application. Current amounts allowed in U.S based systems (150 grams) and the proposed maximum amount of 1 kilogram are currently below the corresponding amounts allowed, for example, in camping propane cylinders that sit on shelves.

Using R-290 for refrigeration is not a new concept; it has been used in other industries such as liquefied natural gas (LNG) production for decades. It is now an ideal choice for many more refrigeration applications because it is able to efficiently scale to fit the size of a system (i.e. air conditioners to LNG production).

In the United States, the race is on to assess the risk of flammable refrigerants, such as R-290, in new locations by January 2021. By 2024, HFCs will be fully prohibited in retail food refrigeration and in air conditioning systems; and it appears other countries will adhere to a similar discontinuance timeline.

So, with all the changes and the questions that persist related to flammable refrigerants, is anyone else asking, “How will this vision of complete elimination become a reality?” NFPA’s response to that is rooted in what our organization calls the Fire & Life Safety Ecosystem.

Last year, NFPA developed the Fire and Life Safety Ecosystem to illustrate how eight key elements interact to model a strategy for keeping people and property safe. If any component is missing or broken, the safety system can collapse, often resulting in tragedy. Almost always we can trace the cause of injurious incidents and tragedies back to the breakdown of one or more components of the ecosystem. Stakeholders have defined roles to play in a safety infrastructure and are responsible for keeping the various wheels churning.

In the case of flammable refrigerants, Government Responsibility is a good place to begin the ecosystem process.

During this phase, elected officials define the policies and safety measures that will keep communities safe from harm, and to hold authorities under their purview accountable. In the United States, that guidance and the enforcement of the Kigali Agreement falls on the Environmental Protection Agency (EPA). The EPA is not only regulating the timetable for the HFC phase out, they will also regulate the process of replacing refrigerants. For instance, current EPA regulations limit the charge size (i.e., amount of refrigerant in a system) to 150 grams per appliance. This benchmark spurs the spinning of the next cog, the Development and Use of Current Codes.

The development of refrigeration codes falls to organizations such as ASHRAE or the International Electro technical Commission (IEC). These organizations create standards that are applicable to all types of refrigeration systems (e.g., ASHRAE 15), and are then factored into product standards like UL 603335-2-40 and primary codes developed by the International Code Council (ICC) and NFPA.

Another component that is important to the refrigeration story points from the primary codes (building or fire codes for example) to Applying Reference Standards. Reference standards take specifically developed standards (e.g. NFPA, UL, ASHRAE) and incorporates them into primary fire and building codes.

The next step that needs to take place to ensure that risk is minimized as we address changes in refrigeration technology, is to ensure that safety is prioritized across the board. A collaborative, cohesive process - with an eye towards safety - is essential if we are going to establish more environmentally sound and low hazard refrigeration solutions for our world. The need for an Investment in Safety was highly evident as the Fire Protection Research Foundation, NFPA’s research affiliate, conducted research on the hazards of A3 refrigerants in commercial refrigeration applications, and invited various stakeholders to discuss the checks and balances that need to be in place to make the transition to flammable refrigerants as seamless as possible.

One of the main findings of this study was that “Servicing generally represents a small contribution to the overall ignited event frequency, assuming that the refrigerant is either recovered or vented prior to servicing and that proper procedures are followed.” As is expected, servicing of flammable refrigerants calls for additional requirements in order to keep incident frequencies low and workers safe. This requires different disciplines such as building owners and operators, contractors, and designers working toward the common goal of safety.

A Skilled Workforce will certainly play a pivotal role in transitioning refrigeration in the years to come. The development of educated and well-trained workers, and their ability to understand and apply codes and standards, will ensure that refrigerators and air conditioners are properly installed and maintained.  To help fill this role, the Association of Home Appliance Manufacturers (AHAM) produces guidelines for the servicing, safe handling, transport, and storage of flammable refrigerants so that appliance technicians are informed about the potential dangers of working with flammable refrigerants. The North American Technician (NATE) is also working in this space to help create technician certification programs and exams, specific to flammable refrigerants.

Code enforcers champion Code Compliance. They are the officials responsible for ensuring that policymakers and practitioners are meeting stated expectations. Sadly, however, the cadence for updating codes in jurisdictions runs the gamut from timely to terrifying.  It is estimated by end users that the inconsistent application of codes and guidelines, and change orders as a result of conflicting interpretations of the code, cost retailers approximately $30-50 million a year. Understandably, it will be much harder for an HVAC professional to meet safety expectations if they do not know what to invest in because of inconsistent and ineffective code enforcement. A moving target, caused by shifting interpretation, is much harder to hit.

Even with the most code compliant installations, unintended fires still can still occur; that is why it is essential that Preparedness and Emergency Response is emphasized in this transitional process.

The first responder community has always stepped up when new threats are present. During the FPRF workshop to assess flammable refrigerant risks in 2018, stakeholders including the fire service, provided invaluable perspective. R-290 may not be new, but emergency responders do need to be trained and educated on the resurgence of flammable refrigerants. That’s why the FPRF and NFPA sought and received an Assistance to Firefighter Grant from FEMA so that the properties and dangers associated with flammable refrigerants could be documented and addressed in NFPA training that will be released later this year (classroom sessions, online learning, and educational videos).

The final component in NFPA’s Fire & Life Safety Ecosystem emphasizes the importance of cultivating an Informed Public. Those in the fire protection industry, the refrigeration trade, and the first responder community will be looked upon to drive an educational paradigm shift. For example, installers will look to trade organizations and business owners to learn about the risks and rewards associated with the new heating and cooling equipment. Likewise, contractors should play an active role in educating clients about new refrigeration and air conditioning technology so that customers can ask questions and be knowledgeable about the risks and actions they need to take to prevent harm.

As the HVAC industry strives to meet the expectations of the Kigali Agreement, it’s essential that we work together, as the Fire & Life Safety framework suggests.  NFPA believes that everyone has a role to play in fire and life safety. Together, by promoting a comprehensive ecosystem of prevention, protection, and education, we can cultivate a risk-free living environment for all.