Man, you guys are awesome. I expected to wait at least a day for someone to respond. Let me try to answer the questions: 1. Where do I live? In Maryland, between DC and Baltimore. You guys know better, but I feel like this climate is split evenly between running AC and heater 2. Dealer reputation? One is very very large regional with a good reputation, but like all Companies that scale, you can find unhappy customers if you look. Other is a state company referred to us directly. Small sample size, but two references were solid 3. On thermostats, both two stage proposals come with new thermostats...the 1 stage uses existing. so hopefully ok there 4. Existing furnace is 120K BTU 5. The Carrier quote commented on the ductwork, but really didnt dig in. The other guy noted it. When, and how, should I press on what needs to be done. Are they inferring nothing needs to be done? Hard to imagine they would miss a chance to charge for more services 6. Load calc...do they do this? how much do they charge? 7. Carrier 1a - 100K, 1b 80K. Lennox 2 - didnt write, but i think he said 100K (second speed at 60K 8. Did i misquote the model #s for all the coils? 9. They both mentioned the filter cabinets, vaguely, and said they were ~$50 and would be replaced annually. Hopefully I gave the answers to get more responses. Thanks again in advance. I truly appreciate the help

Two things from the start. Trane and Carrier are both top of line depending on models quoted. And second, I am not a proponent of the Nest thermostat and would not recommend using it on a Carrier Infinity furnace or a Trane XV80 furnace. You need to verify your AC condenser size for upstairs system. If going to a larger condenser size whether single or two stage, ductwork should be evaluated as to size and if it is large enough both supply and returns to handle the extra CFMs. This is important! Here are the two quotes I like. Trane quote B I want to know the furnace size quoted and the model evap coil quoted. I recommend a two stage thermostat like HW VP IAQ and have dehumidify on demand set up. New lineset included? New filter cabinet? Carrier Quote D What model evap coil? I recommend the Infinity controller. Without it, you would be crippling a nice system. Same questions as to Trane-lineset, filter cabinet. If you want to go lower, take the Trane quote A, upgrade to the XR13 condenser and XT80 furnace. Same as to lineset, filter cabinet, thermostat HW Mdl 8321. Would probably add $750-$1000 to that quote but certainly not a bad system. Just don't like the XB series condenser or the low end XB furnace. Again what evap coil? You need to get past the Nest thermostat. Sorry. Post back. IMO

Thank you for the prompt reviews! Looks like Proposal #1 is the winner so far. Mike ��" the attic fan made a huge difference in second floor comfort. One of the best things I did. Glad your experience was the same. I will look into the 2 stage AC. I will not run the fan or put in an extra return for the humidity/temperature change issues. I will just continue to use my dehumidifiers. They do take care of the issue. I am going to plan on replacing the line set ��" it is easy to get to. What do you think about the drain pan/wet switch that will shut off the AC if there is a leak? Is it going to go off over nothing like a smoke detector I used to have and drive me nuts? Or is it a good idea? I might not have been clear about one thing. Both contractors told me to keep the old air filter set up (Spaceguard High Efficiency). It is the old Aprilaire humidifier that Contractor #1 said replace due to age/parts and Contractor #2 said keep it, parts are not going to be a problem and the only part that goes bad is the solenoid. Keep the old one or buy a new one? Contractor #1 is going to look into the Carrier early failure of heat exchangers settlement. It might only apply to the secondary heat exchanger. The primary one failed on my furnace. I meet with the last contractor tomorrow. I hope to have all the bids by the end of the week. My goal is all new equipment before I have to turn on the heat!

Yeah I'm high and dry thankfully, the roads are a mess up here so traffic delays will likely be a nightmare for a few weeks if it can stop raining more a while to let us dry out. I think part of the problem you're getting is the manufacturer dealer you are using. You see Trane and American Standard are mostly one in the same. They force contractors that use them to exclusivity deals meaning they can't offer other options that are made by other manufacturer's. If they went behind Trane / American Standard and offered these solutions they would probably get chopped off at the knees. The other part may be that they pre-purchased equipment to get better pricing and they have a lot of that equipment in stock from the past year. That is about the only rhyme or reason why I think they are probably telling you these things, because they are totally inaccurate. Certainly any 5 ton system SEER rating will diminish when it is operating in 2nd stage, but in terms of running in 2nd stage usually this will only be in the hours of heavy loads. Typically between 3pm and 6pm. Certainly if we get a heat wave it may run more in 2nd stage during longer spans than those times above. You can easily prove this to yourself when you watch the weather forecast on TV. Pay attention to the highs and lows of the day. Notice that lows are over night (usually) and the highs aren't hit until around 3pm-4pm usually. Well if the average low in summer is around 70 degrees there is far less load on the home than the high of 95 degrees or more. In other words a two speed AC system will most likely run in first stage for hours outside the 3pm to 6pm window. Which means 1/8 of the day it runs in 2nd stage... unless a heat wave or you're cranking settings etc. The flip side is that because the system has 2 stages it runs longer in 1st stage... during all this time it is removing humidity. Lower the humidity and you feel much more comfortable. When deciding make sure the system is a 2 stage with a 2 stage thermostat minimum. SEER ratings are tricky because you could have a 17 SEER single speed air conditioner. The single speeds are the ones not worth it because you don't get the dehumidify punch from those... they are either on or off. Realize it's not only just about efficiency it's also about comfort.