I have a 2500 sq ft home and I just had to install a 5 ton Rheem condensing unit and replace everything up in the attic. My contractor is telling me that I need to add another return air. The one that I have is 20 Inch X 25 Inch X 1 Inch and is located in the hall. Four of my air supply vents are in the master bedroom area of the house and there are only 8 in the rest of the house. I am thinking about adding another return air and 4 more air supplies. Also, my contractor was very against these new filters that take allergens, smoke, etc out of the air. They are too restrictive. So I went and got the cheapies.....Does any of this sound kosher? Am I headed in the right direction? Also, I have discovered that the windows are not calked on the outside or on the inside of my house.....I am in the process of correcting that now.....

I have a 1950, pier and beam, 900sf, frame house. I need to keep the air flowing to cool the place without having to use the a/c so much. I found the attic vents, cleaned them out. I checked all the registers around the outside of the house, all of them are clear. --One of the threads mentioned a fresh air intake. How do I find it? --In my garage, there is an area that should be venting, but isn't. The vents are clear, but I can't get any air flow whatsoever. (Massive hot air buildup) Should I cut another register on the outside of the house, or should I be looking for something else?