I have 2 estimates so far. 1 is for York Affinity 80% efficiency modulating gas furnace and Latitude 80% single speed. The other is for Goodman 80% single speed and he told me a "2 stage" is not available for me because I have a"down flow" furnace system.
This is still confusing to me. Is a "2 stage" the same as a "modulating"? Any suggestions or explanations?