Hi - I want to thank everyone for the input on the "did I buy the wrong furnace" thread - lots of good data, and the thread went in more directions than I anticipated.
Lost in the discussion however, was one question I was really really trying to get an answer to...
If I compare a single-stage FHA furnace, and a two-stage furnace of the same size....
1) Compared to the lowest fan speed of the single stage, roughly how much slower are the 'extra-low' fan speeds in the 2-stage (the speeds that are used when only one stage is on)? 20%? 50%? more?
2) When both stages are on in the two stage, will the 2-stage designed to move -more- air than the single stage?
This information (which I should have asked for before the install) will go a long way to help me gauge whether the recommendations I received to avoid a 2-stage for my unusual, archaic duct system were correct.
Thanks, I really appreciate the help