Hey Ed, are returns required in every room?

In this edition of "Hey Ed," Ed discusses Manual D's requirement of an uninterrupted path for the air to come out of a supply outlet and get back to the fan.

Hey Ed, are returns required in every room? I have been asked the question about returns being in every room quite a bit as of late because apparently I have some areas of the country where there’s an opinion that this is a thing and it’s not. Manual D specifically states that an uninterrupted path for the air to come out of a supply outlet and get back to the fan is required. That can be done with returns in all appropriate rooms, not appropriate would be a bathroom or a kitchen, or a central return can be used as long as some sort of transfer or door undercut is in there which allows that unrestricted path for the air coming out of a supply outlet to get back to the fan and that’s the way I see it.