How much return air do I need?
I bought a house at the end of last summer and I have been having problems getting the temperature to balance. Let me start with some background info that may be helpful. The house is 2 stories and about 1500 fininshed sq ft (750 each floor). The furnace is a Rheem Classic 90 plus,high efficiency, natural gas, 60,000 Btu. I do not know how many tons the AC is. Ten year old house with 4 year old double pane windows. I live in Northern KY. There is a single air return vent, high on the wall, on the first floor about 13"x6". The second floor has two return vents. One of the vents is high and the other is low on the wall, both are 23"x6".
When we moved in we were still running the AC. It was always cold on the first floor and hot on the second floor. One of the return air vents on the second floor was blocked with cardboard (I'm pretty sure that it was the top one). I removed the cardboard hoping that I would get more flow from the vents on the second floor. It didn't seem to work.
Now it is winter and the 2nd floor is still hot and the first floor is still cold. Should I be blocking one of the return air vents on the second floor? Which one? Is it typical for the return air vent on the second floor to be so much larger than the first floor?
I thought about running the blower continuously but it is really loud. It is kind of a strange pulsating sound that echoes through the house. I have read in other posts that it is loud because it is high efficiency and has to move a lot of air.
Does anyone have any recommendations on how to balance the temperature in the house. I plan to add to the problem by finishing the basement and tying into the system. I am probably best off just calling an HVAC guy to evaluate the system. How much do you think it would cost to have a consultation? I think that is enough questions for now...