I"m a big fan of dual fuel. (natural gas furnace for extra cold and heatpump when mild). It doesn't have to cost that much money. There are other brands of equipment available and plenty of contractors who don't have high-priced jobs lined up willing to work for reasonable amounts of money. Other brands offer equipment for less money and very likely just as good. There is a website I think called acwholesalers.com. You can get an idea of what the gas furance and heatpump equipment actually cost. Everything else your paying is labor. Some contractors have a way of know when the 'got one'. That means a guy who doesn't know how much equipment costs and is willing to spend lots of money and can make the contractor plenty of money. Don't get me wrong carrier and trane equipment isn't cheap but I don't always think its worth some of these high priced quotes I see around. In a climate like yours (atlanta Georgia), a heatpump would do you very well. Most of your cold weather is above 30 degrees. Heatpumps provide cooler air so they run for a longer time and evenly heat rooms.

wcb a couple of questions and observations. what area of country do you live? what is your electric rate? both systems are top of line. The Trane furnace is two stg,the Carrier furnace three stg. I have to give the Carrier system the edge because of the Infinity controller, simply the best on the residential market. If you elect Carrier and decide on dual fuel, then I would drop down to the Infinity 96 furnace which is two stg. I would stick with the Performance 15 AC or HP because it is compatible with the Infinity controller altho the Comfort series will work OK. If you elect Trane, you definitely want the HW VisionPro IAQ stat which is superior to anything that Trane offers. The XL16i is OK as AC condenser. If you elect dual fuel, drop back to the XL15i HP which has superior heating BTUs over the XL16i. Keep in mind that evap coil selection will determine best operating efficiency and performance numbers. This is most important. What are you doing about air quality? I would stick with a good 4-5" pleated media cabinet MERV 10. IMO

Great Post! I am in your situation almost exactly. My first estimate came with a rec. of Carrier, Trane, or Bryant for the same type of system you describe. My guy went with Bryant as they are made by Carrier, but less expensive. He said no to Trane as I live in Florida but 10 miles from the water and he would have suggested Trane as it has aluminum coils which would have been better for rusting if I lived my the water. He is giving me your air handler but the Bryant Legacy 215A as I do not want a 2 speed compressor. Since my elec. bills are low, he said the extra money for the Bryant Preferred 16 seer heat pump would not be a good enough pay back for the outlay. Anyway my price is $6570...quite a bit higher for something that is supposed to be cheaper than Carrier. Any comments here would be appreciate. I have 3 more "salesmen" coming, and I know someone is going to add Rheem to the list. From what I've read about Rheem, you either love them or you experience has been so bad that you hate them. So to you question:what is the best variable speed air handler with humidity controls matched with a single speed 15 seer heat pump? Thanks. Lenore

One thing a variable speed (as opposed to variOUS speed) blower can do is run at a lower speed on AC in order to perform humidity extraction. My Trane starts very low, then low and stays there for a while (several minutes). It then slowly picks up speed and reaches its highest setting. At shutdown, it slows down quickly then blows at very low for about 30 seconds before stopping. The heat profile is similar though the highest setting is more like medium. A modulating furnace will modulate (or change up and down) the gas flow to match the amount of heat that is needed. A single stage 'regular' furnace is all on / all off. A 2-stage would be off / half / full or something similar. I generally like to think (and others will correct me) that a condensing furnace is so efficient that the gas exhaust temperature is low enough that water vapor 'condenses' in the flue. A less-efficient design would have hotter exhaust and the vapor would not condense but go out the vent.