A regulatory move extends the sell-through for legacy systems — planning now prevents surprises later.
The U.S. Environmental Protection Agency (EPA) on Sept. 30, 2025 published a fact sheet proposing to remove the Jan. 1, 2026 installation limit for residential and light-commercial HVAC systems built with components manufactured or imported before Jan. 1, 2025.
Why should distributors and sheet-metal fabricators pay attention? Because the change affects which air-handling units, rooftop curbs, curb adapters, and knock-down curbs you spec, stock, and schedule for winter and early-spring jobs.
What’s happening now
Original regulatory language under the American Innovation and Manufacturing (AIM) Act of 2020 (via the “Technology Transitions” rule) set the manufacture/import cutoff at Jan. 1, 2025 and installation cutoff at Jan. 1, 2026 for systems using high-GWP refrigerants such as R-410A.
With the new proposal, equipment manufactured/imported before Jan. 1, 2025 could continue to be installed beyond Jan. 1, 2026.
The EPA has extended the comment period to Nov. 21, 2025.
Why it matters for curbs and accessories
- Distributors: Your inventory planning for curbs and adapters hinges on which rooftop units will be installed. If contractors continue specifying R-410A-based equipment into 2026 and beyond in practice, your pre-fab batches, lead times, adapter sizing and stock-keeping decisions should reflect a mixed install base.
- Sheet-metal shops: Knock-down curbs, adapter kits and mounting accessories often differ by unit footprint, refrigerant type and accessory clearances. If your job orders assume only low-GWP/A2L systems going forward, but the market installs legacy R-410A systems longer than forecast, you risk mis-prefabrication or stock leakage.
- Project timing: With most orders falling between May and September for new construction, now (November) is when Q1 and Q2 2026 jobs are being tendered, specified and budgeted. That means decisions made now will determine lead-time alignment for mid-winter fabrication manufacture and site delivery.
The practical takeaway
Even though the rule is still a “proposal”, you should act as if the extended installation window will proceed. That means:
- Review outstanding quotes and project pipelines to identify which units are manufacture-date pre-Jan. 1, 2025 vs. new low-GWP units.
- Align your adapter and curb stock-lists by scenario: legacy R-410A systems vs. upcoming A2L-/low-GWP systems.
- Engage your OEM / distributor channel contacts now to confirm which models, refrigerants and manufacture-dates you’ll actually receive for Q1-Q2 2026.
- File a comment if you wish: contractors, distributors and users have until Nov. 21 to submit feedback to the EPA on docket # EPA-HQ-OAR-2025-0005.
The bottom line
For purchasing teams and fabrication shops in the HVAC roofing-curb channel, this proposed EPA change signals a longer bridge period for R-410A-based systems. The knock-on effect touches installation timing, adapter batching and inventory risk. Planning now means you won’t be caught off-guard when specification windows shift or contractor orders roll into early 2026.
By the numbers
- EPA proposal published Sept. 30, 2025.
- Comment period extended until Nov. 21, 2025.
- Equipment subject: systems manufactured or imported before Jan. 1, 2025. Installation cutoff originally Jan. 1, 2026 now under reconsideration.
- Original rule set GWP limit of 700 or less effective Jan. 1, 2025 for new systems.
Remaining uncertainty: Whether the final rule will impose additional conditions (e.g., labeling, inventory thresholds) or revert to the Jan. 2026 installation stop. Confidence: ~75%.
