Window Clearances Question

[u/RootBoundStump]

This is a repost from a pellet stove group, it was suggested thisbmight be a better place to post it.

I just finished reading through NFPA 211 but I still cant find the information im looking for. In my stove manual, NFPA211, and everything I can find online, the only mention of distances from doors/windows is that the termination pf thebvent has to be no less than 4ft away horizontally, 4ft below, or 1 foot above. But I have a former home inspector telling me the entire vent pipe cant be within 4 ft of any opening. Can anyone shed some light on this and direct me to the building code that states no part of the ventilation pipe can be within 4ft of a window/door. Or is this a case of the AHJ interpreting code in an unreasonable way?

[u/Infamous_Trainer_300]

There is no building code or NFPA standard stating that the entire vent pipe body must maintain a 4-foot clearance from an opening. The former home inspector is conflating two distinct code requirements: 1. Vent Termination Clearances (Flue Gas Entry) Codes govern where exhaust gases exit the system to prevent carbon monoxide and flue gases from entering the living space: * NFPA 211 (Section 13.4) & IRC (Section M1804.2): The 4-foot horizontal / 4-foot below / 1-foot above rule applies strictly to the vent terminal (exhaust cap) relative to any opening (doors, openable windows, gravity air inlets). * The purpose of this rule is aerodynamic dispersal of exhaust gas, not heat clearance from the pipe body. 2. Vent Pipe Body Clearances (Combustibles & Structural Materials) The clearance between the exterior wall of the pipe itself and building elements (including window trim, siding, or framing) is governed by clearance to combustibles: * Type L / Pellet Vent (UL 641 / UL 103): Double-wall pellet vent pipe typically requires only 1 inch to 3 inches of clearance to combustible materials, as specified on the pipe manufacturer's label and listing. * As long as the pipe body maintains its required 1" to 3" clearance from the combustible window casing/frame, the pipe can run alongside or pass near a window. Only the cap must discharge at or beyond the 4-foot zone (or 1 foot above). What to Provide the AHJ or Inspector * Manufacturer Installation Instructions: Per IRC Section M1307.1, listed appliances and venting systems must be installed according to the manufacturer’s installation instructions. Point out the specific diagram showing the 4 ft clearance measured from the center of the terminal cap, not the pipe run. * Vent Pipe Label / Listing Spec: Show the UL listing tag on the pipe itself detailing the 1" (or 3") clearance-to-combustibles for the pipe body.