Refrigerant regulations and low-GWP options in Canada

Refrigerants in Canadian HVAC equipment are going through their biggest change since the phase-out of CFCs. Hydrofluorocarbons (HFCs) such as R-410A, R-134a and R-404A do not deplete ozone, but they are powerful greenhouse gases. Canada is reducing their use under the Kigali Amendment to the Montreal Protocol, and equipment manufacturers are moving to refrigerants with much lower global warming potential (GWP).

For owners and designers, this affects what equipment can be bought, how machine rooms and occupied spaces must be designed, how technicians must be trained, and how long existing equipment can be economically serviced.

The regulatory framework

Refrigerant rules in Canada come from several levels of government.

Federal regulations

The federal Ozone-depleting Substances and Halocarbon Alternatives Regulations (ODSHAR), made under the Canadian Environmental Protection Act, 1999, control the import, manufacture and use of ozone-depleting substances and HFCs. They include two main tools for HFCs:

• A consumption phase-down. Canada's allowable HFC consumption, measured in CO2-equivalent tonnes, is being reduced in steps from a baseline. The schedule follows the Kigali Amendment for developed countries: a 10 percent reduction in 2019, 40 percent in 2024, 70 percent in 2029, 80 percent in 2034 and 85 percent from 2036 onward.
• Product GWP limits. Certain categories of new products manufactured in or imported into Canada cannot use HFCs above a set GWP. For example, new chillers have been limited to refrigerants with a GWP of 750 or less since January 1, 2025. Other limits apply to specific refrigeration and foam products.

The phase-down does not ban existing equipment. Systems already installed can keep operating and be serviced, but the supply of high-GWP HFCs will tighten over time, and prices may rise accordingly.

Federal regulations are amended periodically. Check the current text of ODSHAR and Environment and Climate Change Canada guidance before finalizing an equipment specification.

Provincial and territorial rules

Provinces and territories regulate the handling of refrigerants: leak testing, record keeping, recovery, venting prohibitions and technician certification. Most require technicians to hold an environmental awareness certification for handling halocarbons, and many require service records and leak repairs within set timeframes. Details vary by province, so owners should confirm what applies to their sites.

Safety codes: CSA B52

CSA B52, the Mechanical Refrigeration Code, governs the safe design, installation and operation of refrigeration systems, including the refrigerant charge allowed in occupied spaces and the requirements for machinery rooms. It is adopted by provincial regulation, so the edition in force varies by province. The 2023 edition includes provisions for the mildly flammable A2L refrigerants that are replacing R-410A in many products. Our guide to CSA B52 covers it in more detail.

Safety classifications

ASHRAE Standard 34 classifies refrigerants by toxicity (A lower, B higher) and flammability (1 no flame propagation, 2L lower flammability, 2 flammable, 3 higher flammability). These classes drive the safety requirements in CSA B52 and in product standards.

The shift to A2L refrigerants is the biggest practical change for commercial HVAC. A2L systems require attention to charge limits, leak detection and mitigation, ventilation and the electrical components near potential leak points.

Common refrigerants and their replacements

GWP values below are the 100-year values commonly used in North American regulation (based on the IPCC Fourth Assessment Report). Values from other assessment reports differ slightly.

Some replacements trade one issue for another. R-513A is non-flammable but has a GWP close to the chiller limit, so it may face pressure in future phase-down steps. HFO refrigerants such as R-1234ze(E) have very low GWP but lower volumetric capacity, so compressors and heat exchangers are larger. Natural refrigerants such as CO2 and ammonia have excellent environmental profiles but very different pressure and safety considerations.

What this means for owners

Buying new equipment

• Specify refrigerants that comply with current federal limits and are likely to stay available for the equipment's expected life, usually 20 years or more for chillers.
• Confirm that the installing contractor and service provider are trained and equipped for A2L or natural refrigerants.
• For systems in occupied spaces, such as VRF and split systems, have the designer check charge limits and leak mitigation requirements under the CSA B52 edition adopted in your province. See our guide to VRF refrigerant piping and leak limits.
• For chiller plants, verify machinery room ventilation, refrigerant detection and alarms against CSA B52.

Managing existing equipment

1. Build an inventory of equipment by refrigerant type, charge and age.
2. Review leak records; systems with repeated leaks are candidates for early replacement.
3. Consider the cost and availability of future refrigerant service when planning equipment replacement and capital budgets.
4. Do not "drop in" a replacement refrigerant without manufacturer approval. Retrofit refrigerants can change capacity, oil compatibility and safety class.
5. Keep R-22 systems on a replacement plan. Supply of HCFCs in Canada is now very limited, and servicing will only become harder.

Leak management

Leaks are both an environmental and a financial issue. Good practice includes regular leak checks as required by provincial rules, permanent refrigerant monitors in machinery rooms (required by CSA B52 for many systems), and documented repairs. Leak-tight systems also run more efficiently, since undercharged systems lose capacity and efficiency.

Frequently asked questions

Do I have to replace my R-410A rooftop units now?

No. Existing equipment can be operated and serviced. The phase-down limits new supply of HFCs, not the use of installed equipment. Plan replacements on normal life-cycle grounds, but expect R-410A service costs to rise over time.

Are A2L refrigerants safe in occupied buildings?

They are classified as lower flammability with a low burning velocity, and codes and product standards set charge limits, leak detection and ventilation requirements to manage the risk. Installed correctly under the applicable code, they are widely used in occupied buildings.

Is CO2 practical for commercial HVAC?

CO2 is well established in commercial refrigeration and is increasingly used in heat pumps for high-temperature water heating. It operates at much higher pressures than HFCs and requires specialized design and service skills.

Key takeaways

• Canada is phasing down HFC consumption under ODSHAR, reaching an 85 percent reduction from baseline in 2036.
• New chillers in Canada have been limited to refrigerants with a GWP of 750 or less since January 1, 2025, and other product limits apply.
• A2L refrigerants such as R-454B and R-32 are replacing R-410A in packaged, split and VRF equipment, with new safety requirements under CSA B52.
• Provinces regulate refrigerant handling, records and technician certification, and requirements vary.
• Inventory your equipment, track leaks and factor refrigerant availability into replacement planning; a high-efficiency HVAC review can align refrigerant choices with energy goals.