We are in the process of replacing a 1 year old...Yes,1 year old 4 ton ($12,400put in Aug.20,2011) air conditioner:TraneXL16i seer:16.5 furnace:TraneXV95 load calculation was done by 5 out of the 6 companies stating we needed a 4 ton unit. We just had a company come out and they said we are oversized by 1 ton and that was the reason for our whole problem?? We have what they call 'dirty sock' syndrome which started 2 weeks after it was installed!! 4 coil changes later still an issue. When we ran it in emergency heat over the winter,without a coil,no smell!!! With Tranes non responsiveness to all I would never get a Trane again!!!!!!!!!!!! Now I've read about all the problems with all units and am more confused then ever,but I do know that I will not get a heatpump again!!! Our original Lennox furnace(19yrsold)began getting stuck/freezing(not turning on) no smell issues whatsoever. Since we had just finished with our D.I.Y renovation of our home we decided to get a new unit,more energy efficient since it was the last thing that was needed to complete our home! I cannot believe how each and every contractor differs on their load calcs...you would think there would be some sort of protocol/procedure to do this accurately and come up with the same numbers?? More confused then ever~smile~Afraid to get that horrendous smell back in my house with another 'coil'...and Yes, we had one dipped and the procedure was done incorrectly , even the contractor said the chemical smell was making him ill...it was in the house for 1 hour and he had to take it out immediately after closing up the unit(took him an hour to install it). We had to air out the house mid winter and sit outside...stress to say the least....Any comments advice would be appreciated~smile~ I too live in W.N.C.

I received the following quote below for an 1200SF house and I live in MA. The quote is for re-doing the entire system from 'ugly octopus' to high efficient furnace! can someone tell me if this sounds reasonable for the cost? I have additional quotes coming in but am not sure what to expect... thanks! Price Includes: Bryant High Efficiency (95%) Gas Fired Furnace  New plenum and return set up with EZ Change Filter Rack  All Ductwork required (re-hung and layout configuration)  New Return Boxes  All PVC venting required  All gas plumbing hung and secured  All high and low voltage wiring  New 5-2 programmable Variable speed thermostat  Condensate pump and drainage  Removal of existing furnace and oil tank  Termination cap for exhaust and supply combustion Total Parts and LaborÂÂÂÂÂÂÂÂÂÂÂÂÂÂ$9,600

I realize this is single stage vs. two stage thread. My goal in stating what I stated was to show there is a realm above 2 stage, more or less as well as to show there are differences from one manufacturer from another. It wasn't my purpose to hijack a thread. There are those out there that say 2 speed equipment is unnecessary... so why would manufacturers make 5 stage equipment and variable speed equipment on top of an already unnecessary system? Many times in the field I've heard of people saying 'I don't want to gold plate anything'. Part of my response was geared to show that 2 stage systems these days are middle tier systems. People change homes so much: yes, this is why my job can be really challenging. Many times it's not replacing a whole system (which would be required to go to a 2 stage machine... in most cases*). Many times my job involves retro fit decisions. Replacing one or two pieces of an older system. In situations like that it's more about repairing the existing system and give a homeowner a solution they want. If I find out a home owner is only planning to stay in the home a few short years I rarely if ever even offer the 2 stage equipment. 2 Stage equipment is for those of you looking to stay in the home for at least a decade or longer. HVAC is not a one size fits all market. I am more likely to repair an existing system in some fashion than to replace. But replacement in some cases is the better option regardless of how long you plan to live in the home. If you live in my climate (Katy, Texas), you will have a tough time to sell a home without a functioning AC system.

tigerdunes thanks, I really do like the idea of having the variable speed and 2 stage heat of the Trane 15 Seer packaged unit at a price marginally higher than the 14 Seer 1 stage units. I looked up the XL824 Trane thermostat and the reviews were not so good compared to others like the Honeywell 9000 (TH9320WF5003) or the ecobee 3 - it seems Nexia also requires a monthly $10 fee to use. Are there other thermostats that would allow for a dehumidication feature by sensing humidity and telling the ac to run at a very low speed without causing significatly lower temperatures than we want? We do travel a good amount particularly during the warmer months and it would be great to be able to control the system remotely (get the ac cooling before we arrive etc.). We also just got an Amazon echo and might want to use Alexa to control the temperature via voice commands. We have been using disposable pleated filters at the 2 air return registers. I asked about a media filter (we have an Aprilaire in the attic for the upstairs unit) but they did not recommend it because we would have to go into the crawl space to change the filters (ceilings are too low and i'm claustrophobic). Company A quoted putting a media filter in crawl space for $225, Company B quoted an air purification system for $800 for both Trane and Carrier options- maybe they are referring to Trane clean effects not sure - i didn't investigate further due to the high cost. Austin Air: it seems packaged units or gaspacks as they call them around here are the norm in homes is NC for the lower level floors as our crawl spaces have such low ceilings. Company A showed me the rust/hole in the heat exchanger and the heater had already stopped working so I think they were telling the truth about it needing to be replaced. We weren't the ones to put in the system in 2005 - i was told the American Standard heat exchanger only had a 10 yr warramty (XE not stainless). All 4 of the companies i talked to said 12-13 years is a normal life expectancy around here due to the unit being outside in the elements and not having a stainless XE. The new units with stainless XE have 10 yrs on parts and 20 yrs/lifetime on XE - of course labor to replace is a factor that's why i was pricing the 10 yr labor warranties -but good point on reading the fine print. Any thoughts on things that would increase the life of the gaspack being that it will be located outside other than the stainless XE i.e. Carrier Armor coat coil tin plating vs. aluminum Spine Fin coils? Thanks again!