I'm looking at a gas furnace (20 year) and AC (15 year) replacement and have some questions primarily about the furnace options I have before me:
80% vs >90% efficiency; is the higher efficiency worth it? I'm in Columbus, OH and my yearly gas bill is ~$1200 and I estimate ~$800 is for heating. Is it simply looking at the % differential and finding an acceptable payback time period?
multiple speed vs variable speed; is variable speed much better than 4-speed?
any other features of a gas furnace that I should consider?
I have quotes on Trane, Lennox and Rheem systems. One definitely recommended the 80% afue, another provided the higher efficiency info when asked and the third's starting point was the high efficiency.
From what I've gathered here, most would say that these manufacturer's all put out good products and that it is the installation that makes for a good working system. Other than that, any particular recommendations for a Trane, Lennox or Rheem?