Joe: First I agree with Mike & Tiger. I question the integrity of a contractor that would propose Infinity without the Infinity controller. ThatâÂÂs a deal breaker for me. I would never deal with that person again unless he fully understood that we can âÂÂargueâ about price but that thereâÂÂs âÂÂno compromiseâ when it comes to doing things right the first time. $800.00 rebate seems low for that combination, but that may be a regional thing. Depending on the cost of energy, you might consider a HP over an A/C unit. The difference the Infinity controller will make is that itâÂÂs a âÂÂCommunicating Interface UnitâÂÂ. There will be 2-way communications between the controller and the gas furnace and the A/C unit. This will enable the controller to be as âÂÂSmartâ as it can in that it âÂÂLearnsâ from previous cycles to make the next one as efficient as possible. This also means âÂÂSmart Recoveriesâ with setbacks of more than 2F. The Infinity controller will also allow for âÂÂDemand Defrostâ should you choose to install a HP. Among other things, the Honeywell controller will not be able to do all these things. SR

Wow - I didn't realize that was a 5-ton blower, thanks for bringing it to my attention. I have two quotes for the Bryant 2-stage a/c 187B with 986T furnace. The one with the 100K BTU is about $9450, (includes installation of 2 dampers) and qualifies for a $500 electric co. rebate. The one with the 80K BTU furnace is about $8901, (no dampers/different contractor), also qualifies for the $500 rebate. I don't have a quote for a single stage a/c with the 986T furnace, but have one for 126B with 925T, 100K BTU, roughly $7100 (w/2 dampers). All a/c units are 3-ton.

I assume you do not have access to natural gas. It would be the most cost effective option. I am not the geothermal expert, but I can tell you the installation costs vary greatly around the US. I suggest you also look at the Carrier Greenspeed heat pump. It is more expensive than the traditional heat pump but will still be significantly cheaper than a geothermal installation.

The biggest problem with HVAC zone systems is knowing when to choose it as a solution and when not to. Some HVAC companies it's about "sell, sell, sell" whether or not it works... there's more money in "sell, sell, sell" --- when it's only about money? So does the comment above mean I do it for free? No. If you think that you are reading things that aren't there. New construction? best to choose separate systems 9 times out of 10. In order for a zone system to work, you have to know what you are doing. Most HVAC companies staff (the techs they send you) are 20-30 year olds. How much practical experience could they possible have? It's best for HVAC zone systems to be an elegant solution. A HVAC zone system is a tool in the tool bag. Not all homes are suitable for zone systems. Some homes there is no other way, and in some cases complications to those problems will make an HVAC zone system design possibly more prone to problems. You have a problem now, do you want more problems. These decisions among others are decided "in person" --- so considering that becareful what information you decide upon from the internet. Just because it's here doesn't necessarily mean it's true. That said: Depending on equipment level chosen, how many different floors you have in your structure, how much room you have available... will all be factors that make you decide one way or another. From there it's in your best interest to pick a contractor that is skilled: especially when it comes to HVAC zone systems. (there's a lot of garbage out there.) (click to enlarge if necessary) I service the Katy, Texas area.