We are looking to replace 5-ton AC unit and 30 y/0 furnace. We are trying to qualify for local utility rebates and need to have functional 15 SEER, variable stage, and manual J completed. I have quotes for several products from several well-known contractors. I believe that it's between Lennox XC-21 and Amana 16ASX (contractor tells me we'll get 15 SEER -- I don't have that written estimate yet).
Questions: Lennox quote says to replace current 3/8 inch in-slab copper set (30 years old) with 1 1/8 and 1/2 inch lines (thru attic and down exterior wall, about 25 feet). In my last post that size was questioned as being tooooo large. Amana contractor says to leave, flush and use current lines. I've read previous threads and know that people have varying opinions regarding this. How do I ask each contractor, without insulting them, what is required for the product. If they don't install right and there is a problem, who's pocket does the repair money come out of (if it is still under warranty)? If it isn't put in according to specifications, is it my problem, or the contractor's problem?
Q2. We have 2700 SF and will need a 5 ton unit. We have 3 - 12x12 inch returns in the house. Amana and another contractor says we need another, yet another contractor said he'd put the system in and THEN see if the air return was adequate. Lennox contractor said nothing about the air return being inadequate. Do we need another return? Thanks, my dad was a HVAC man and I truly miss the ability to call and ask him these questions. Y'all helped a great deal in my last post.