Another $5-6k? That's a lot for a new furnace when you're already adding A/C. I'm surprised they didn't give you a better deal. I'd recommend changing the furnace out with a variable speed furnace. It helps with humidity and more even temperatures throughout the house. You won't get higher efficiencies with an older furnace. That American Standard "14 SEER" unit will likely get less than 14 SEER if it's not paired with a variable speed blower. How was the size of the A/C needed determined? This is very important. You want a correctly-sized unit. Make sure each dealer did a Manual J load calculation to determine sizing.

Glazed:

You MUST have the model numbers of the condenser (outside unit) and evaporator coil on the quote to 1)prevent the "bait and switch", 2)ensure that the coil is a proper match to the condenser, and 3)have enough info to check out performance and efficiency numbers.

Post the model numbers of the condenser and evap coil and myself, Ryan, or TigerDunes will provide you efficiency and performance numbers.

I wouldn't replace a 7 year old furnace, but that's just me.

You won't be using the a/c that much in Colorado. I wouldn't go too crazy with a high-end a/c system. I'd get basic 14 SEER system (always better to get a little better than basic builder's grade 13 SEER) with a matching coil and use the existing gas furnace.

Best to you.

"You won't be using the a/c that much in Colorado. I wouldn't go too crazy with a high-end a/c system. I'd get basic 14 SEER system (always better to get a little better than basic builder's grade 13 SEER) with a matching coil and use the existing gas furnace."

I agree. The problem is making sure you get the full 14 SEER while using the older furnace. The only A/C I can foresee you having an issuing getting 14 SEER out of is the American Standard. For example, a 3.5-ton 4A7A4042 Allegiance 14 R-410a air conditioner with 4TEC3F42 (not variable speed, 3.5-ton) air handler gets 13.25 SEER--13.50 SEER with the 4TEC3F48 4-ton air handler.

If people are paying 5k for furnaces in Colorado I need to move

Here is a link that might be useful: Air Conditioning and Heating Repair Made Easy

the proper way to do this is have them rework a new proposal with furnace,condenser,evaporater coil installation and MUST INCLUDE ALL MODEL NUMBERS. to insure you get exactly what you get. your location 13 seer is just fine. dont waist money on higher seers if the thing is not running much a season. oh yea get at least 3 qoutes

I live in Denver and just recently had install a new Trane Two Stage variable speed 80K BTU 95% AFUE furance with humidifer,50 gallon Hot water heater and got my old AC unit remove for $4500. Furance also had a $100 dollar rebate from Trane. How this helps

Update: The Lennox dealer mailed us a written bid to add the furnace. The total to add the furnace is $4382 indlucidng a $230 multi-system discount. It's a G71P60C-110 with 110,000 BTU and 95% efficiency, two-stage, variable speed fan. The Lennox A/C is XC15-042 3.5 ton up to 14 seer unit. I agree about getting a third quote, though the Lennox dealer installed a new furnace in our previous old (1908) home and we are pleased with the quality of work they do.

I'm not sure I understand what a manual J load calculation is. I know the Lennox salesman used his calculator quite a bit before he wrote the bid. The American Standard salesman did also; and they both came up with the same 3.5 ton, 14 seer number.

Gary, I'm not sure why you think we won't use the A/C much here. Our upstairs is swealtering at night in the summer, after the sun has blasted our entire west side. The temperature in our bedroom is often 80 degrees or so when we go to bed. The summers have been quite hot for the past five to seven years. The season may not be as long as Phoenix, for example, but it gets pretty hot.