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High efficiency direct vent boiler venting question

55Trucker Member Posts: 17
Hi everyone. I am in the beginning stages of converting from an oil-fired FHA heating system to an LP-fired high efficiency, direct vent FHW system. I have a question about venting.

At one point the footprint of my house was expanded on one side, by about 8'. The extension was built on posts, and there is a 3' high crawl space under part of my living room as a result. (The foundation was left unchanged.)

The existing FHA furnace sits next to the basement wall that has this crawlspace on the other side. Ideally, my new gas boiler will be mounted on the same wall when the old furnace is removed. Every venting and air intake picture I have found shows the boiler on a basement wall, and the venting and air intakes going out the wall and vertically, with the pipes 3 or more feet apart and the heights 12" or more away from each other. My questions are:

1) Can I take air in from the crawl space? It is a 3' high x 8' wide x 26' long space with wood lattice on one length and one side.

2) I know I can't vent in the crawl space, but I would need 8'+ horizontal run across the crawl space to vent out the side of the house. Is that permitted?



  • STEVEusaPA
    STEVEusaPA Member Posts: 6,377
    You should grab the installation manual online for the furnace you will be using to determine how it can be vented.