I've had three contractors come out and quote systems for me. The first one said 2.5 tons, the second said 3 tons and the last said 3.5 tons. I looked at my furnace and I don't think it will support a 3.5 ton system.
I have a 6 year old Trane XV90 DY080 (down flow 80k BTU) The inside panel has a table with settings for setting the Tonnage and setting the CFM. My furnace is a downflow and has a * by the 3.5 TON setting and it says "only on the upflow model." I have a down flow model.
There is also a setting for CFM/TON and the options are 350, 400, and 450.
So I'm curious what would happen if I went with the contractor that quoted the 3.5TON system with existing furnace would they just say ops, I guess we'll set it for 3 and up the airflow to the 450 and call it good enough, or if they would say, "hey that quote I gave you, tear it up. You need an air handler". Or would the size the coil larger to make up for less airflow to get the rated SEER? Am I overreacting?
Is the CFM capability of the furnace something they typically check before quoting a system, or was that guy cutting corners?
Should I call him back and ask or is this a red flag to move on?