Cold air returns and supply lines - both high in room
We have a 6 year old home that is gas forced with a/c unit. Our first floor has heat registers in the floor. The second floor of our home has all of the registers in the ceiling.
Each room on the second floor not only have the heat/ac supply coming through registers located on the ceiling, but we also have cold air returns in each room and those are located high on each wall.
My problem is that it is very difficult to cool the upstairs. I am thinking that our cooled air is being blown in through the vents on the ceiling and being sucked right out by the cold air returns located high up on the wall. I know ideally that you would want a cold air return high in warm temps to pull the hot air out of the room, but that would be with your supply coming from the floor level, correct?
I was thinking of closing off the high cold air returns and cutting a low cold air return. Does anyone think that this would help with cooling the space?
I also believe that this is a problem in the winter as well. I think we suck the warm air straight across the room and right back into the cold air return.
Any idea or thoughts are appreciated. I have a searched all over the web and can't find anyone with the same problem.