I had an HVAC company install a new heating and air conditioning unit, and they ran PVC ducting up to the attic and out the side of the house with a downslope for drainage. I'm considering cutting a PVC Y into it to connect my bathroom exhaust. Is this a bad idea? I'd even insulate the pipe, but I really want to avoid making a hole in the roof.
3 Answers
Absolutely do it out the side! Exhausting through the roof isn't necessary for bathrooms. Just make sure you add a wall cap to prevent any drafts or water entering when the fan isn’t running.
Definitely do not connect your bathroom exhaust to that PVC! It's a really bad idea. The slope is important for drainage, and adding a Y could mess that up. Also, you need at least a 4-inch diameter for the bathroom exhaust; that PVC probably isn't large enough. It's best to just run a separate pipe out the side of your house instead.
It's against the code to connect bathroom vents to HVAC systems. Each has to have its dedicated exhaust. You can simply add another pipe next to the existing one for your bathroom exhaust. This method is much safer and effective!