[Stangkiller]

Originally Posted by bill_daniels

I guess I don't understand this. I, like Jeff, have two units, upstairs and down. Each unit has one return air duct, which is where the filters are installed. If I block off the where the upstairs system sucks in air, am I not basically making it difficult for the system to breathe? That seems like a guaranteed way to make the unit fail quickly.

Yup it'll freeze up pretty quickly. Maybe Dabs suggesting to close off and not cool the rooms upstairs that you don't need to cool? Closing those doors will help create back pressure and push cold air to the open spaces too.