Just moved into my new home in the Austin, TX area. Carrier HVAC unit. My question is about the ceiling registers. There are 2 register in each of my bedrooms, one is a supply air and the other looks like a return but there is no filter. The main return register in the hallway with a filter. I'm curious as to why the other vents in the bedrooms don't need filters like the big hallway return vent?
Thanks for the help.