Finally got the quote from the 2nd Trane dealer: Furnace: XV95 + Honeywell VisionPro IAQ, new air supply ducting to upstairs bedroom, new cold air return on main - $5865. Furnace Model No. TDH2B080A9V3VA This has an output of 49,400/76,000 BTUH for stage 1 and 2. My current 80% AFUE Heil is rated 75,000 BTUH input, so this XV95 has at least 25% more heating capacity. Heat Pump Option: XL15i - $5905 complete. Model No. 4TWX5036B1000A (3 ton capacity, house is 2300 sq ft, 2-story) Installed with Trane Coil, Model No. 4TXXCB036BC3HCA (other dealer quoted a 4TXCB036BC3HCA, so maybe the above is a typo?) ARI Ref# 1384223 Cooling Capacity, 34800 EER (cooling), 11.40 SEER (cooling), 13.5 Heating Capacity @ 47F, 37200 Region IV HSPF (heating), 8.3 Heating Capacity @17F, 24200 This doesn't exactly look like a very stellar system combination for the price as none of the specs on the HP/coil combo would qualify it for the $1500 tax credit. I do believe the XV95 would qualify however. The other problem is I don't think the furnace or the HP would qualify for our local utility rebate of $350 since you can't get the rebate on a 90%+ furnace if installed as a backup system with a HP, and I don't think the HP listed here would qualify on it's own. Guess I would have to install the furnace and coil 1st, claim the rebate, then install the HP or AC if I felt like it. It's all too damn confusing. Pricing from all the dealers is pretty close, but the quotes are not exactly apples to apples so it is a bit hard to judge. I thought the XL15i had much better efficiency ratings that listed above. Think I need a quote on an AC unit instead of the HP as I still don't like the idea of the 95% AFUE furnace just sitting there most of the time. Would love any input or suggestions.

Here they are. one 3 ton and one 2.5 ton. Carrier ARHI 3656405 58CVA909-16 80% Infinity 2 stage gas furnace CNPVP3717ATA tin plated copper coil 24ACC636A003 3 ton Comfort series A/C TP-PAC EDGE Programmable Thermostat Cost $6380 58CVA070-12 80% Infinity 2 stage Gas furnace CNPVP3014ATA tin plated copper coil 24ACC630A003 2.5 ton Comfort series A/C TP-PAC EDGE Programmable Thermostat Cost $5885 Both Carrier systems come with Perfomance series media cabinet. Trane: 15i A/C systems and XV80 furnaces 3233365 Active Coil (Mix-Match) ASPEN TRANE 4TTX5030A1 ASPEN MANUFACTURING C(A,C,D,E)30D44+TDR *UD060R9V3 30000 13.10 16.00 1 RCU-A-CB 216 Yes Cost = $5825 3233463 Active Coil (Mix-Match) ASPEN TRANE 4TTX5036A1 ASPEN MANUFACTURING C(A,C,D,E)36D44+TDR *UD100R9V5 36000 13.30 16.50 1 RCU-A-CB 251 Yes Cost = $6023 Tcon802 thermostats Aprilaire 4200 series SPaceguard media cabinets 2 at $225 each Both say I have super air flow and neither will change the line sets. They are in 'great shape' and run through finished space. Will clean, flush, etc. Incl is new electric disconnect and poly pad for each system. The above costs are the prices I pay the contractor. The are withing $50 in total, once I include the filter media. I also get a federal tax credit of $1500 plus a Va. state grant of $2000. What tips the scales in favor of one over the other?

Thanks to everyone for your replies and advice! ryanhughes -- No, I did not share sizing info among contractors; they all came to 3.5 tons on their own. I did, however, mention to Company 3 that I already had an estimate for a 90K BTU furnace, so Company 3 guy said, "well, I was going to suggest 80K, but in that case, let's go with 100K." Also, I did let all estimators know that I'm planning to add on 150-200 sf in the next year or two, so they should take that into consideration. baldloonie -- Nope, not much insulation. some was blown into the attic floor in the 70's, so it's (somewhat) compacted now. Otherwise, nothing at the roof, in the crawlspace orin the walls. And yes, lots of windows -- at least those have been upgraded to double-pane. It's been stinkin' hot this year with several weeks of 90+ temps so far... and we're probably in for a few more (it's a dry heat, though ;-)). Winter nights can get into the 30's during cold years. A few more questions... 1. Company 3 also sells York, and I'm looking into the LX series A/C for space reasons (smaller footprint). In terms of sound levels (dB's) nd reliability, what's your take on Carrier Comfort/Performance vs. Trane XR13/XL14i vs. York LX series? 2. Would I be better off with a completely matched system (e.g., Trane furnace/Trane A/C), or can I mix and match furnace and A/C (e.g., Trane furnace, York A/C)? 3. A couple of the estimates I received included the option to add on a higher-end air filter -- Carrier Infinity (Company 1) or AprilAire 2400 (Company 3). Is it worthwhile to do this? 4. I have allergies and pets. Is there a noticeable difference in adding an air cleaning system? I guess the real question here is "are they worth the money?" 5. Company 3's estimate is about $2K higher than the other two. I assume this is due to the higher price of Trane components, the additional fabrication for the sound-attentuation work, and their fabrication of an "accessible" filter box. Thoughts?

tigerdunes -- thanks for your input! Much appreciated. That is the direction I'm heading, subject to final price, warranties, etc. (The last quote from Company 2 had the Infinity furnace with the Comfort A/C.) The tendency here seems to be the "1 ton / 500 sf" approach. I've been pushing the final two dealers to really be sure about their sizing by giving them as much info as possible (the number of windows in the house, no insulation, orientation, etc, etc.) vyasmk9 -- I'm on the Peninsula -- as are all of the contractors I've contacted. It just seems that people around here seem to service a smaller area (although I could be wrong), plus I like to support local biz whenever I can. Just FYI, I started by selecting a couple of well-known brand names (Trane and Carrier) and looking on their websites for local dealers. Followed that up with searches for reviews of those dealers on local.yahoo.com and yelp, as well as checks on the BBB. Also asked my electrician and utility company guy for their thoughts/referrals. Not sure what the forum rules are for recommending contractors, so I'd rather ask before naming names. Anyone want to comment?