Clothes Dryer venting

Any issues with a dryer vent going to a larger pipe and then back down to normal size? It doesn’t seem right to me, wouldn’t the air slow down and accumulate lint? I can’t find anything in the standards about it. Thoughts?



M1502.3 Duct size.
The diameter of the exhaust duct shall be as required by the clothes dryer’s listing and the manufacturer’s installation instructions.

I would mention it, It will collect lint

I don’t think the smaller duct going to a larger duct is an issue, it’s where the larger duct transitions into the smaller duct again. The smaller inner seam will definitely collect lint and clog. Simply recommend upgrading to equally sized dryer exhaust piping.

What the hell would homeowners do without duct tape?