Hard to say without knowing more about your home. How much insulation you have in the attic and walls, number and type of windows etc. Did the present unit keep you comfortable when it was operating correctly? Do you have a lot of windows facing south and west with little shade? I live in central South Carolina and finished off an 850 s.f. upstairs in my last home. Put a 1.5 ton heat pump in and unfortunately it didn't keep up with the summer heat and had to be replaced with a larger unit...so tread carefully when downsizing it might be a very expensive mistake.

Got my first quote: Ground floor: Gold ZM 95% variable speed furnace 100,000 BTU $2500 AC: Platinum XM Series 18 SEER 3 ton $3175 All furnace install quotes include: new thermostat, any needed gas line, metal work, electrical box, electrical whip, labor and taxes. 10 yr parts warranty, lifetime heat exchanger warranty and 1 year labor. All AC install quotes include: new thermostat, new copper line set, air conditioner pad, disconnect, electrical whip, labor and taxes. Platinum XM AC series has 12 yr compressor warranty, 10 year parts warrant, 10 year coil warranty and 1 yr labor warranty. I have various Gold and silver series AC and furnace quotes from same guy that top out in the 2800 dollar range for gold line for both AC and furnace unit for 2nd floor space. What do you think? Thanks, Jeff

First off, I think you must ask dealer what upgrades you need to make to your attic where dealer will guarantee against freeze ups. That's if you are serious about placing a high eff condensing furnace in attic. Then get pricing from an insulation contractor and/or dealer if he provides that type of work. Weigh the cost of the upgrade and decide if it's worth it. I think quote #1 is ridiculously high. Good comprehensive list though for scope of work. Compare to the other quotes for apples to apples. On quote #2, I want R8 insulation up and down. I don't believe you require a 90 KBTU furnace for upstairs area. I would want to see the load calc to support that size. Drop down to 70 K model. I assume Infinity controllers for both systems. How many returns on each floor? I would want two returns on each floor, properly sized and strategically located. Filter cabinets on both systems? I think a 3 ton condenser for upstairs is oversized and would suggest going down to a 2 1/2 ton Sgl stage high eff model. Don't like that condenser on the Trane quote. I would like to see evap coil model numbers. What about filter cabinets? What model thermostats? Is this rental property? Who will remove old radiators and old pipes and make necessary repairs including flooring? These are just some general observations. IMO This post was edited by tigerdunes on Tue, Aug 20, 13 at 13:02

Home builders are pretty much a dime a dozen and the first sign of trouble with the housing market they blow away like tumbleweeds. HVAC brands don't really matter all that much these days. Installation is key. The more premium equipment would be 2 stages or more clear up to complete variable speed (inverter technology). The only reason I suggest higher efficiency equipment is that California is known for some of the highest utility rates in the country, the most energy efficient equipment you can buy 'might' be in your best interest. (full variable speed inverter technology)