My exhaust and intake vent pipes are in a terrible position for finishing my basement soffit. They run under my heat and return trunks and then up between floor joists to the outside wall. It looks like I can maintain the the correct slope if I go up and over the heat and cold air return trunks, however, I would have to go between the floor joists through one of the branches off the cold air return for a couple feet. Can I do this?
The B149.1-20 Gas Code would not allow this in the province of Ontario,
QuoteClause 8.10.12 - A flue gas vent or a vent connector shall not be installed in either a duct or a shaft used for return air, hot air, ventilating air, or combustion air.
If the joist is lined and acting like a return air, you could just buy some duct board and reduce its size and box out the venting, so the venting was outside of the return air cavity.
Thank You for response. I assumed that was the case but hoped it was not.