Replacing HVAC for leaking evap coil
My home in Phoenix presently has a Tempstar (ICP) 9600 A/C with gas furnace, installed 1995. Evap coil has developed leaks every 1 to 3 years requiring multiple replacements, fortunately covered by extended warranties. Service people have always seemed puzzled by the repeated leaks but from reviewing forums it looks like this is a recognized problem.
Looking at Lennox or Trane for full replacement - are these the best, is one rec. over the other?
One estimate is for Lennox XC21-048-230 condenser with an ADP LC42/60Y9CG coil, the guy said that Lennox uses ADP coils; with Lennox G60UHV-60C-090 furnace.
Second estimate is for same Lennox condenser, and furnace, but with Lennox CH33-50/60C-2F coil - for a lower overall price.
Other option would be Trane such as XL20i.
Does this Trane have aluminum coil, which it looks like doesn't have the rust/leak problem?
If I go with variable speed furnace/air handler and leave fan on full time will this prevent condensation and rust on the coil and reduce chance of leaking?
Is the proposal to use an ADP coil a scam or legit?