Hi,

i am new to this forum and i dont know anything about AC Units. i have a trane 5 ton system in a two story home that is two years old. my home is 2600 sq ft. i have terrible heat and air balance. i have had about 5-6 ac companies come out to give advice and estimates on what i need to do to correct this. at its worst spots there is an 8 degree difference between downstairs and upstairs with dwn being the coolest and up the hottest. the master bedroom is the hottest room in the house. upstairs i have three returns...25x13, 26x19, 13x13 and downstairs i have one return 13x13. all companies have told me i need to zone out the system, which i'm ok with but....i have always thought that the return downstairs was small and not big enough, but out of all the companies that have been out there only one has brought it to my attention that its a big problem. they recommend before i zone the unit to enlarge the 13x13 to like a 30x30 and then balance the unit. they said if this doesnt work then zone the system. i am ok with that but if doesnt work i am 3k in the hole. i have actually drawn a picture in paint to show a layout of the house and my vents and returns but i dont see a way to attach it here. i would gladly send to anyone that is willing to help and would like to see it.

my wife and daughter also have allergy issues so i want to add a filter system - april air - to the unit but the same person that wants to enlarge the duct told me that if i add a filter system it will decrease my cfms. no one else has mentioned this.

any advice/suggestions would be appreciated.