R-404A was widely used in walk-in coolers and freezers, but it has a very high global warming potential, about 3,922 according to EPA material. Federal HFC rules restrict its use in new systems and phase down HFC supply over time. Existing R-404A systems can keep running, but service costs and availability may change.
If your walk-in was installed before the mid-2020s, there is a fair chance it uses R-404A. The refrigerant worked well for both cooler and freezer temperatures, which is why it was so common.
Why regulators care
R-404A traps far more heat in the atmosphere than carbon dioxide does. EPA material lists its global warming potential at 3,922. Refrigerants with lower values are being pushed into new equipment, and the total supply of HFCs is being reduced under the AIM Act.
What the rules do
- Limit the global warming potential of refrigerants in new equipment in certain sectors, including retail food refrigeration.
- Phase down the amount of HFCs that can be produced or imported.
- Do not require you to scrap working existing equipment.
The technology transitions rules have been under reconsideration, with EPA proposals in 2025 and later actions in 2026, so dates and limits have shifted. Ask your technician or supplier what applies to a system you plan to buy.
What it means for existing systems
| Situation | What to expect |
|---|---|
| System running well | Keep maintaining it |
| Small leak | Repair and recharge, refrigerant cost may rise |
| Major failure | Compare repair with replacement using a newer refrigerant |
| Planning new equipment | Expect lower-GWP refrigerants, see R-448A |
What you can do
- Confirm the refrigerant from the nameplate.
- Reduce leaks with regular checks and quick repairs.
- Keep records of refrigerant added.
- Get a replacement quote before a failure.
- Ask a new-equipment supplier which refrigerant it uses and how it is serviced.
Do not mix and match
Do not top off an R-404A system with another refrigerant without a proper conversion. Mixed refrigerants perform poorly and can damage components. Only a certified technician should handle it, and the work must be recorded. See why a certified technician must handle refrigerant, leak repair rules and repair or replace.
Refrigerant rules are set by the EPA and have been changing, so this page is general information. Confirm current requirements with your technician or the EPA before making decisions.
Talking to your supplier
When you ask about new equipment, ask which refrigerant it uses today, whether it is likely to remain compliant in the near future and how local technicians will service it. Ask for a written description of the refrigerant, charge amount and oil type. Keep that with the equipment records, because the next owner or technician will want to know.
Questions about this topic
Do I have to replace my R-404A walk-in?
No. Existing equipment is not required to be replaced solely because of the refrigerant. Rules affect new equipment and supply.
Will R-404A get more expensive?
Prices may change as supply is reduced. Ask your technician for current information.
Can I switch an R-404A system to a newer refrigerant?
Sometimes, through a proper retrofit by a technician. It depends on the system.