Hi, and I apologize if this is a really lame question or has been gone over many times before.
I purchased a new home two years ago and I have been having problems with the AC in the house. The house is 3400 sq feet, has a 3 ton AC (or it may be 3.5... I forget), and no matter what we do, we can not comfortably cool our house. The front of the house faces east, and the rear of the house faces west. Lots of windows on both sides.
The first summer we moved in, we had the HVAC contractor fix a few things. We had him adjust the fan speed as we were hardly getting any air flow on the far vents (still, we are hardly getting any air flow, but more than we were), we had him increase the return duct that attaches to the side of the furnace (when we took the cover off where the flower is, it would literally suck itself back onto the unit and I felt it was air starved and thus causing a return air flow problem.
The problem I have is this though... I can't get my house to stay cool. Even on a 80 degree day, my house can't stay cool.
I want to have an HVAC contractor come and fix it, but I'd like to know first off what the issue might be.
One question I have is do I have enough return air? Right now, I calculated how many return ducts I have and I have a total of 11 ducts that have a size of 1008 square inches. Would increasing the ducts help air flow, or is there possibly an underlying issue with the return line? Most of the ducts are 14x6, and in some of the very large rooms where we have 4 or more supply vents, we only have one small return vent.
Secondly, I do not have any noise or strong sucking by the return vents. Would this indicate that the blower fan may be undersized?
Any help would be appreciated.