By Daniel Robert, Ing, LEED PA.
ASHRAE 2022-2023 Society CTTC (Chapter Technology transfert Committee) Chair,
Senior VP, Special Project, Kolostat-Krome Inc
Photo Credit: JBC Média par Foulques Delbar

Over the past few decades, several significant legislative changes have constrained the use of certain types of refrigerants in the HVAC industry. In 1986, Canada’s signing of the Montreal Protocol marked the abandonment of R-11 and R-12 refrigerants. This was followed in 2010 by the elimination of R-22, which changed the design of all comfort cooling HVAC applications for both residential and commercial systems, large and small.

Today, most air conditioning systems runs on R-410A (small and medium capacity residential and commercial), while the large chiller market uses R-134a. Unfortunately, all this is going to change, and faster than you think!

A new regulation

With the signing of the Kigali amendment (2015), ratified by a large number of countries, including Canada in 2020 and the United States in 2022, the door is shown to R-410A and R-134a. With a Global Warming Potential (GWP) of 2088 for R-410A and 1430 for R-134a, neither of these refrigerants meets the limit of 750 imposed by the new regulations. Following the agreement, Environment Canada and the Ministry of the Environment, the Fight against Climate Change, Wildlife and Parks of Quebec will prohibit, as of January 1, 2025, that chillers using refrigerants having a GWP of more than 750 are manufactured, distributed or installed.

Alternative solutions

The next-generation refrigerants are, for the most part, less efficient than those they will replace and may be somewhat dangerous since some are slightly flammable. ASHRAE has developed Standard 34, which classifies many available refrigerants considering their Ozone Depleting Potential (ODP), their GWP, their toxicity and flammability. Low or non-toxic refrigerants belong to class A, while those which prove to be toxic fall into class B. To classify refrigerants flammability, ASHRAE has divided them into categories 1, 2L, 2 or 3; those of the category 1 being non-flammable and those of category 3 being highly flammable. For example, propane (yes, it’s a refrigerant, and it has the number R-290) is classified as a A3, while ammonia (R-717) is classified as a B2L refrigerant.

Unfortunately, new refrigerants are not perfect, and the industry has had to compromise on alternatives to meet global warming reduction goals and replace R-410A and R-134a refrigerants, both in category A1.

Different manufacturers consider R-454B (GWP = 466), R-32 (GWP = 677) and R-452B (GWP = 676) as replacements for the outgoing R-410A (GWP = 2088). These three candidates belong to the A2L category: they are not very toxic but have a certain flammability. You will therefore understand that the safety rules surrounding their use differ from what we have been accustomed because of their possible flammability.

As for R-134a (GWP = 1430) that is mainly used in large capacity screw or centrifugal chillers, the replacement refrigerants are the R-513A (GWP = 573) and R-515B (GWP = 299), both A1 refrigerants. These refrigerants are compatible with compression technologies similar to those currently used in positive pressure chillers. Other refrigerants operating at low pressure (much like R-11 and R-123 did) could be used in large capacity chillers: either R-1233zd (GWP = 1), an A1 refrigerant, or R-514A (GWP = 2), a refrigerant classified B1 (toxic). These two candidates require new generation chillers that are completely different from those currently found on the market.

Some complications

As indicated above, rooftop units, direct expansion splits, VRF units, residential units as well as small to medium capacity chillers will (almost) all use in the future class A2L refrigerants (therefore non-toxic or minimally toxic, but slightly flammable), a major change from the A1 refrigerants currently used. ASHRAE published Standard 15 in 2022, which establishes best practices for the installation and handling of A2L refrigerants. This standard has already been adopted by several American states (such as California and New York, to name just two). In Canada, the CSA B52 code, last revised in 2018, governs the safe use of refrigerants. Developed using most of the ASHRAE 15-2013 standard wording and protocol, the (old) B52-2018 significantly limits the use of A2L refrigerants in systems with a high risk of leaks, including rooftop units, splits and VRF units. This drives to a dead-end. The adoption of new version of the B52 is therefore crucial.

I remind you that certain states and countries, including our neighbors to the south, are further along in the process of replacing refrigerants, and that large manufacturers are already implementing their transition. Here, Environment Canada and the Ministry of the Environment, the Fight against Climate Change, Wildlife and Parks of Quebec will require from 2025 the use of refrigerants having a GWP below the 750 in chillers, but the others air conditioning systems will also necessarily change refrigerants, since manufacturers will stop producing the existing units using R-410a or R-134a in order to address the requirements of the most demanding/stringent and/or high volume markets.

The need to act quickly and adapt.

There is still hope as the new B52-2023 code is currently under final review. According to the information I have, the code should be ratified in Canada in the coming months, possibly in January 2024 and should define, among other things, the rules for a safe installation method for systems operating on A2L class refrigerants. In Quebec, the B52-2023 will become law six months after its publication, probably a few months before many systems operating on R410A and R134a are forced to disappear from the market. Let’s hope that the final version of the B52-2023 will not have any last-minute surprises in store for us! It is good to know that the RBQ intends to adopt B52-2023 without additional modifications, which will allow it to be applied as soon as it is ratified by the Canadian government.

Considering the long delivery times for chillers, one needs to understand that there is very little time left for building managers to order current generation refrigeration equipment and thus avoid purchasing new generation units operating with A2L or B1 refrigerants, which will likely require significant and costly modifications to the mechanical rooms. I strongly suggest that building managers contact their consultant, qualified mechanical contractor, or chiller supplier quickly to plan properly this transition of refrigerant, especially if their current chiller plant is at the end of its life.

But wait, it doesn’t stop here! The Kigali amendment, to which, let us remember, Canada subscribed, impose that in 2029, we will have to reduce our greenhouse gas emissions by another notch (30% reduction). It is a safe bet that the legislation surrounding the use of halocarbons will be reviewed quickly. Look at the GWP of new refrigerants and you will understand that very few will remain in use if the targets are reduced again. This is why all experts call next generation refrigerants “transitional refrigerants”. Only time will tell us which refrigerants will be able to be used. Expect to hear about a new group of refrigerants: HFOs (hydrofluoroolefin), whose GWP are close to 1. Perhaps CO2 (GWP = 1) will become the refrigerant of choice and possibly even propane/ R-290 (PRP = 3) but for this to happen, legislation will need to be proactive and make place for propane (A3 refrigerant) in the building code and allow building managers to prepare their mechanical room for this eventuality.

Canada is currently reviewing its legislation, but time is running out. It is essential that building managers and industry professionals prepare for these major changes that will impact air conditioning and refrigeration equipment. The recess is truly over. The future of air conditioning and refrigeration is being redefined. It is high time to prepare for this new reality.