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

ionized - thanks for the comment and I will definitely look into adding a humidifier later on vs at the beginning. I moved from a house in the North Hills that was your typical 1950's Pittsburgh Cape Cod and in the winter we had a big problem with static which I would like to dry to avoid in my new home. I realize I might be off the mark for my reason on humidity control but in general, I just want to do this system right because I have that option. to all - can anybody give me a range that I should be paying for a new high efficiency system (as spec'd above) from either Trane, Carrier, Amana/Goodman, or York for my size house? Quotes as mentioned before are on top of each other so thats what makes me comfortable with them but it would be nice to hear from someone on here as a sounding board. Thanks to all the previous comments and suggestions.

WHAT IS A HIGH LIMIT SWITCH? https://www.newcentralairconditioner.com/ The high limit switch in your gas furnace is a small part with two very important jobs. This switch plays a role in the normal operation of your furnace. Turning the fan motor on and off is the high limit switch’s main job. This is the role it plays in every cycle of your furnace’s normal operation. But that’s not the only thing that the high limit switch does. It’s also safety device that helps prevent your furnace from overheating. The high limit switch consists of a long temperature-sensing probe attached to a metal mounting plate. From the mounting plate, the switch is wired to the blower fan motor and to the gas valve. The switch is generally located just past the heat exchanger. This is so that it can detect the temperature of the supply air. In other words, the air that’s about to be blown into your home.

I completely agree with Fudd (and would have used a stronger word than "baloney.") Any company that won't do a "Manual J" load calculation on your home should NOT be hired to install your new system! Here is a good explanation of why doing a load calculation is so important: https://www.pvhvac.com/blog/why-the-manual-j-load-calculation-is-key-to-hvac-design And a 96% efficient furnace is definitely preferable to the 80% offering (in which 20% of the gas you purchase to make it run -- is wasted.) In this day and age, please go with the furnace that only wastes 4% of the gas you purchase. Even your gas utility bill with thank you, with lower monthly costs to run your new furnace (than if you'd bought the 80% efficient version).