PTAC Condensate Drain Code Requirements: What IMC 307.2 and IPC 314.2 Mean for Hotel Projects
Every PTAC in a hotel guest room pulls water out of the air, and that water has to go somewhere. On a 150-room property, that adds up to a lot of water every cooling day, spread across 150 small drain pans and 150 openings in the building envelope. The code sections that govern where it goes are short, but they’re easy to misread, and the confusion usually comes down to one question: what applies to the PTAC unit and what applies to the sleeve around it.
This guide walks through what the International Mechanical Code and International Plumbing Code require, how those provisions apply to a hotel PTAC opening, and what architects and MEP engineers should put in the specification.
What does the code require for PTAC condensate drains?
IMC Section 307.2 and IPC Section 314.2 require PTAC condensate to drain to an approved place of disposal through piping at least 3/4 inch in size, sloped at least 1/8 inch per foot. Overflow protection is required where damage could occur, and traps are required where the unit manufacturer calls for them.
The authority having jurisdiction (AHJ) decides how those requirements apply on a given project, and the adopted code edition matters, so check which edition is in force before you cite section numbers in a spec.
Which code governs PTAC condensate?
The same condensate provisions appear in two codes. The IMC is their primary home, in Section 307. The IPC repeats them in Section 314, marked with an [M] to show they’re maintained by the mechanical code committee. In Florida, they appear in the Florida Building Code, Mechanical (Section 307) and Plumbing (Section 314).
For HVAC condensate, cite both: IMC 307.2 / IPC 314.2, or FBC-M 307.2 / FBC-P 314.2 on Florida projects.
The six provisions that matter for a PTAC opening
The 2021 IMC also limits where condensate can discharge. Drains can’t connect directly to plumbing drain, waste or vent piping, and unless they discharge to grade outdoors, the point of discharge has to be within the same occupancy or tenant space (IMC 2021, Chapter 3).
A related requirement: the louver
PTAC louvers fall under IMC Section 401.5, which covers intake opening protection. Transient hotels are Group R-1 residential occupancies, so they fall in the residential row of Table 401.5: louver openings not less than 1/4 inch and not more than 1/2 inch. In hurricane-prone regions as defined by the IBC, louvers protecting air intakes must comply with AMCA 550, the high-velocity wind-driven rain test (IMC 2021, Chapter 4).
What to put in the specification
Condensate gets lost between trades when the PTAC unit is in Division 23 and the louver and window are in Division 08. These items keep it on the drawings:
● The condensate route for each PTAC, internal drain line or discharge through the louver, with the point of disposal shown
● Drain size of at least 3/4 inch with no reduction downstream, citing the adopted code edition
● Minimum slope of 1/8 inch per foot on condensate piping
● The auxiliary protection method chosen under 307.2.3, and who provides it
● Trap requirements taken from the selected PTAC unit’s installation manual
● Cleanout or maintenance access that doesn’t require cutting the drain line
● A cross-reference between the Division 23 and Division 08 sections so one of them owns the sleeve pan, drain connection and sill flashing
End the condensate section with the same note the code implies: final compliance is determined by the AHJ.
How the NeverLeak™ sleeve is designed around these provisions
The NeverLeak™ PTAC sleeve was built around the problems these code sections describe. It uses a sloped ABS drain pan and a 3/4-inch drain connection, consistent with the 3/4-inch minimum in IMC 307.2.2 / IPC 314.2.2. Insulation sits above the pan’s flood rim, which lines up with 307.2.3.2. Treatment pellets can be added through the sleeve sidewall without removing the chassis (US Patents 10,746,417 and 11,466,893), which supports the maintenance intent of 307.2.5.
The NeverLeak louver and wall sleeve assembly is covered by Miami-Dade County, Florida NOA No. 22-0914.08, Expiration Date March 26, 2031. Its evidence includes AMCA 550 wind-driven rain testing of the assembly.
Frequently asked questions
A PTAC condensate drain should be at least 3/4 inch under IMC 307.2.2 and IPC 314.2.2, with no reduction in size between the drain pan and the point of disposal. Recent editions specify 3/4-inch pipe size, so confirm the wording in the edition your AHJ has adopted.
A trap is required when the PTAC unit’s manufacturer calls for one. IMC 307.2.4 and IPC 314.2.4 tie trapping to the equipment manufacturer’s requirements, so check the selected unit’s installation manual.
A PTAC needs one of the four auxiliary protection methods in IMC 307.2.3 where overflow from the primary drain could damage building components. Whether a sleeve pan qualifies as an auxiliary pan is decided by the engineer and the AHJ.
PTAC condensate must go to an approved place of disposal and can’t discharge where it causes a nuisance, such as onto a walkway. Under the 2021 IMC, it can’t connect directly to plumbing drain, waste or vent piping.
In hurricane-prone regions as defined by the IBC, IMC Section 401.5 requires louvers protecting air intake openings to comply with AMCA 550. Outside those regions it depends on the local code and the project specification.
Specifying PTACs on a hotel project? Request the NeverLeak™ submittal package, with the drawing set, approval documents and specification language, or book a Lunch & Learn on PTAC water management and code for your team.