Problem: 2.5 ton unit, 1400 square ft upstairs, I live in Lutz Florida. During the day the longest runs start to warm up (in other rooms), temps 82-86 degrees. AC working fine, at night I can drive the temp to 68 degrees.
I have had ridge vents installed, a solar vent, I have more venting than than spec. The attic space is no more than a crawl space, the AC ducts are running almost at the top of the roof line (I have tall gabled roof). The ducts are flexible and I cannot keep the upstairs cool. I have had AC guys out to look, all want to put in a 3 or 3.5 ton unit to replace the 2.5 ton.
I am looking at radiant barrier installation but the roof is so close to the ceilings (the inside ceilings are gabled like the rook outside, they match within a foot or so at places with a 3 foot gap at the top) I am not sure I can even do it. I though about using metal straps to box in the ac ducts, cover partially with radiant barrier, blow in insulation, then complete covering the ducts with the radiant barrier.
I am at my wits end, any help/suggestion would be greatly appreciated.