Why Part 84 compliance requires linked equipment tracking.

The AIM Act Part 84 rules took effect January 1, 2026. They sit on top of the existing Section 608 framework and dramatically expand who has to track what — lower charge thresholds, new substances in scope, tighter recordkeeping. Most HVAC contractors we talk to are partially aware of the rule and partially unprepared for the recordkeeping shift it represents.

The shift is structural. The EPA defines an "appliance" — for both Section 608 and Part 84 — as the full refrigerant circuit, not its individual components. A residential split system is one appliance. A 4-zone mini-split is one appliance. A commercial refrigeration rack with eight evaporator cases sharing a condenser is one appliance. Leak rate, repair verification, recordkeeping — all of it applies at the appliance level.

Most HVAC field service software — Housecall Pro, Jobber, ServiceTitan, FieldEdge — stores each piece of equipment as an independent record in a flat list. There is no concept of an evaporator and its matched condenser being one appliance. Which means the software's view of "the unit" doesn't match the regulation's view of "the appliance," and the contractor ends up reconciling by hand.

TuffOps is the only HVAC field service platform that models equipment the way the regulation does — through a feature called linked equipment groups. We didn't build it for compliance specifically (it solves a much more common, day-to-day field problem we wrote about over here), but compliance is where its absence in other tools becomes a real exposure. This post is about why.

How the EPA actually defines "appliance"

Under 40 CFR Part 82 Subpart F, an "appliance" is a device containing and using a refrigerant, including the full refrigerant circuit — not the individual components. A residential split system is one appliance. A 3-zone mini-split with one condenser and three evaporators is one appliance. A commercial rack system with eight evaporator cases sharing a condensing unit is one appliance.

This matters because the key compliance thresholds apply at the appliance level:

• Section 608 leak rate thresholds (10% annualized for comfort cooling appliances ≥50 lbs) are calculated against the full appliance charge, not per component.
• Part 84 / AIM Act thresholds — effective January 1, 2026 — apply to appliances containing ≥15 lbs of a refrigerant with a global warming potential (GWP) greater than 53, with certain carve-outs (notably RLCA and ODS-only appliances). Again: one appliance, one charge, one set of obligations.
• Repair verification and recordkeeping obligations travel with the appliance. If you fix a leak on the evaporator side of a split system, the repair verification record attaches to the whole appliance, not just the coil.

So your software's job, if you want it to be useful for compliance, is to know which records are "one appliance" — not just "one piece of equipment."

What happens when your software gets this wrong

If your field service tool treats each unit as an independent record (most do), the compliance math gets awkward fast. Here's what breaks:

1. Leak rate calculations become guesswork

Your system doesn't know what the full appliance charge is, because it only knows about the condenser's nameplate. Was refrigerant added to the condenser or to the evaporator? Either way, it's the same circuit. But if your records show "added 4 lbs to the condenser" and "added 2 lbs to the evaporator" as two separate events on two separate records, nobody's leak-rate calculator is going to add them up correctly unless a human manually does it.

2. Repair verification doesn't roll up

Under Section 608, when you repair a leak, you have to verify the repair within a set window — and that verification record has to be tied to the appliance. If you repaired the condenser and verified it at the condenser record, but the customer's next tech sees a "leak detected on evaporator" event on the other record, your audit trail looks incomplete. On paper, it is.

3. Warranty and install dates get fragmented

Matched-pair warranties are common — the manufacturer warrants the pair, not the individual units. If your software treats them as independent, your warranty-expiration reports have to be cross-referenced by hand, and you risk either missing claims (cost you money) or offering warranty work you're no longer entitled to (also costs you money).

4. Commercial refrigeration becomes unmanageable

This is where the flat-list model really falls over. A supermarket rack with eight low-temp cases sharing one condensing unit is one appliance with one charge. Under Part 84, if that rack is over 15 lbs of high-GWP refrigerant — which it will be — it's in scope. Tracking leak rates across nine disconnected equipment records is simply not something a dispatcher can do reliably on a Monday morning.

What "linked equipment groups" looks like in TuffOps

Available on Pro and Enterprise plans, TuffOps lets you group a condenser with its matched evaporator(s) — or a refrigeration rack with all its evaporator cases — as a single linked system. In the UI, any unit that's part of a group gets a chip that shows the group size ("part of 3-unit system") and lets you jump to any of the other members with one click.

What that means operationally:

• Leak-rate calculations roll up to the appliance. When a tech logs refrigerant added on any member of the group, Comply (our compliance module) treats it as added to the shared charge. Leak rates are computed on the actual appliance the EPA cares about — not on an arbitrary single-unit record.
• Repair verifications are group-level. A leak detected on any member is a leak on the appliance. The verification record attaches to the group and is visible across all members.
• Service history is unified. When a tech opens any unit in the group, they see every visit, photo, note, and refrigerant event for the entire appliance — not just the one they're standing next to.
• Warranty and install dates stay aligned. Matched-pair warranty expiration is one date on one group, not two dates on two records you hope nobody forgets to check.
• Audit exports respect the grouping. When you need to produce records for an EPA audit or a customer who's due diligence on their own footprint, the export comes out appliance-by-appliance, the way the regulation reads.

Every other HVAC platform gets this wrong

We built linked equipment groups for everyday matched-pair tracking pain (the full story is here). But it's also the only HVAC equipment model on the market that fits the way the EPA defines an appliance. Here's what the rest of the market actually offers, viewed through the compliance lens:

Platform	Equipment model
Housecall Pro	Each unit is an independent record in their Property Profile app. There's no way to link two pieces of equipment as a paired system. The workaround is to use naming conventions like "Downstairs Evaporator" and "Downstairs Condenser" and hope everyone remembers they go together.
Jobber	Doesn't have equipment tracking at all. Workarounds are custom fields on the property, job checklists, or bolted-on third-party inventory apps.
ServiceTitan	Their "Equipment Systems" module stores installed equipment per location and links forms, services, and memberships to it — but each piece of equipment is still a standalone record. There is no equipment-to-equipment grouping that ties an evaporator and its condenser together as one appliance.
FieldEdge	Has a parent-child hierarchy, but it's for customers and locations, not equipment. Every piece of equipment still lives as an independent record against a customer.
TuffOps (Pro & Enterprise)	Equipment groups are a first-class concept. Any unit can be linked into a system — split pairs, mini-splits, VRF, commercial refrigeration racks — and leak rate, repair verification, service history, and warranty all roll up across the group.

Every one of these platforms will let you service a split system. The question is how much manual reconciliation you do to stay compliant — and how many records you'll have to stitch together by hand when an EPA auditor asks for your appliance leak-rate history.

Want to see equipment groups in action? Book a 30-minute demo and we'll walk through a real split system and a commercial rack, including how leak rate rolls up across the group and how it exports for an audit.

What to ask your current vendor (or a prospective one)

If you're evaluating HVAC software right now — or reconsidering the one you have — here are the questions that matter for Part 84. Don't accept hand-wavy answers; make them show you in the UI:

1. "Show me how you represent a split system in your data model." If the answer is "it's two separate equipment records," follow up with the next question.
2. "If a tech adds 3 lbs of refrigerant on a service visit, how does the system know the full appliance charge for leak-rate calculation?" If the answer requires a spreadsheet or manual reconciliation, that's your answer.
3. "How would I represent a 6-evaporator commercial rack in this product?" Watch their face.
4. "Can I export refrigerant records for an EPA audit appliance-by-appliance, or only unit-by-unit?" The regulation is written appliance-by-appliance. Your export should match.
5. "If I repair a leak on the evaporator and verify it, does the verification record attach to the full appliance or just the evaporator?" The right answer is "the full appliance."

These are fair questions. A vendor that's taken Part 84 seriously will have answers. A vendor that's still treating HVAC as a generic "trade" will stumble, and that stumble tells you something.

Bottom line

Linked equipment groups are a feature we built for everyday HVAC field operations — eliminating the matched-pair guessing game, keeping warranty records aligned, and letting techs see the shape of a system the moment they walk up to it. The full story is here.

For any shop with a meaningful Part 84 exposure — commercial work, light-commercial volume, refrigeration, or any system above the new 15-lb threshold for high-GWP refrigerants — they also happen to be the difference between an audit you can pass and an audit where you're explaining a spreadsheet to the EPA.

Linked equipment groups are available on the Pro and Enterprise plans in TuffOps, alongside the full Comply module for refrigerant and EPA tracking.

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