What about cutting a hole from the laundry room into the garage and running a metal vent from there up the wall of the garage, across the ceiling, and through the other garage wall to the outside. This would give us a metal vent and a much shorter run than we have now. But is it okay to run such a vent through a garage? I think it would have to be insulated as the garage is unheated. Are there building codes that would prohibit this? I'm in Ontario.
Answer:
I don't know about building codes because they're so minimal that in most cases like this, they don't count anyway. I see nothing wrong with running the rigid metal duct across the garage and if it happens to drip condensation, yes, I would certainly wrap insulation around it.