Osburn 5" x 25' Insulated Flex Pipe for Fresh Air Intake

Twenty-five feet of insulated 5-inch flexible pipe for the outside-air connection on the Osburn Horizon. The Horizon manual limits 5-inch pipe to runs under 20 feet with no more than two bends; a longer run, or one with more bends, must use 6-inch pipe, and no run exceeds 30 feet, so on the Horizon this pipe never runs its full 25 feet. The pipe must be HVAC type (ULC S110 / UL 181 class 0 or 1) and withstand 250 °F; clamp both ends, and Osburn recommends a P-trap loop against condensation and rust. Pair it with the 5-inch termination with clamps and the 5-inch airtight intake register. $165.