ECN Forum Forums General Topics of the Trade General Discussion Area Panel and related questions from a new member

One answer is easy. Run a short rigid nipple across that void with a slight down pitch so water can't intrude, punch a hole in the cabinet at the appropriate place and be sure you install a bonding bushing on the end. Then put some duct seal on the outboard end to exclude moisture bugs etc. We don't know how it terminates outside but he will need some kind of bushing there too.

Example of a bonding bushing