My house was built in '61 and was 100% electric with no air conditioning. At a later point (we think 60s-70s) the electric baseboard heating was removed and a forced air system was retrofitted. We use that same basic system with a newer (2010) furnace and central air conditioning system today. The house is basically a 2000 sq. ft. ranch with a full basement.
The round duct is 6". The floor registers in the bedrooms are 2"x12" and are "plumbed" in from below like this:
I am no HVAC person but that feels like it would constrain the airflow at that juncture and that I could get more air through if I was to replace that with a 3"x12" or 4"x12" transition? Or is that all I could expect out of the feeder pipe?
I know that there is supposed to be a balance in the AC system but I just feel like this is very restrictive. The room is also closest to the AC and is consistently the hottest in the house.
I would like to make the existing system work better so I am open to any suggestions. But if need be we could do something like adding a in min split although that will be a bit ugly.
There are two vents into the room like the one pictured each on the N and W walls and then a 4x10 return on the south wall. We always keep the door open since it is a half-broken pocket door with a broken track. But fixing that is a different question.
If you look at it from above the house is shaped like a capital T with the bedrooms lined up across the top. The bedroom in question is the "west wing" and as such gets all the late afternoon sun so I am certain that solar load is playing a big part directly and indirectly via the attic.