Arkansas HVACR NewsMagazine November 2025

HVACR NewsMagazine November 2025

State National Chapter News

Codes and Changes that Affect Fort Smith HVAC Contractors

To Fort Smith Builders, Contractors, Owners

5- Dryer vents under slab can only be ran in PCD pipe (polyvinyl coated Ductwork) or 26 gauge metal in 2 inches of concrete with 3 mil plastic wrap around concrete, and come up in 6 inch wall to a dryer box. If dryer is ran up wall it needs to be 28 gauge start in a dryer box and not be oval or deflected must stay 4 inch round start to finish. If straight back through wall to outside then can be 28 gauge but no dryer box is required. All termination kits for dryers must be metal. 2021 IMC 504 6- Line sets running on the outside surface of residential or commercial buildings must be in a line set cover to within 6 feet of the equipment it connects to. 7- Commercial duct thickness starts at 28gauge (up to 10inch) and goes up, Residential duct starts at 28 gauge and goes thicker as it gets larger. 2021 IMC Chapter 6 8- If a house is going to be foam then the inspector needs to know on rough in, there are different requirements for fresh and make up air, as well as on type of furnaces and requirements for combustion. 9- If you are foaming a Commercial building and the foam is not encapsulated then a 15 minute vapor barrier (intumescent) is required on any exposed foam. (Attic areas and exposed areas) must meet 25 flame 50 smoke rating.

There are many new mechanical codes and changes that the State HCAVR Division and the State Mechanical Inspectors have advised our city staff of. The City of Fort Smith Mechanical Inspection Staff is trying to make everyone aware of them. Here are some of the major changes that effect construction and remodels so that everyone is on the same page. 1- Drains for HVACR equipment cannot go to sanitary sewer. Some can drain in grassy areas while others will need to go to storm or French drains areas. City of Fort Smith ORD 25-207 2- You can no longer have combustibles in the return on residential construction. This includes underside of platforms if used, water heaters, drains, electric, pumps, etc. If the unit is located in the garage or closet accessed through the garage then insulated metal (26 gauge) will have to be used as the return and metal (26 gauge) will be run through the sidewall, ceiling, floor from garage area then 28 gauge metal or flex can be ran after that point. If located inside the house surrounded by conditioned air then you can line it with sheetrock, duct board, or metal and seal. 2021 IMC 602, 2021 IBC 703.5 3- When setting condensers outside in front of electric (service, disconnects, meter bases) or windows and doors used for emergency egress you must maintain 36 inches of clearance. 4- Commercial (multifamily) has the same code requirements on indoor air handlers, furnaces as residential on what can be in the return air plenum or duct. (see #2)

10- All primary drain terminations must be marked in green. (Tape, paint, etc.) 2021 IMC section 307

11- All condensate drains will have a clean out before the trap. 2021 IMC section 307

12- On existing equipment change outs, the equipment cannot set on a wood platform, it must either have