One of my thermostats recently died after 10yrs so I started looking for a "smart" thermostat. After browsing the web I concluded I'd try the Nest (crowd fav) and the Ecobee3 (newest model but ecobee seems to have a very good reputation online). I wanted to share some of my initial thoughts between the two since there isn't much out there yet. Before buying these stats I realized I needed the 24v common wire connected and luckily our house was wired with 6 strand wire and all I had to do was hook up the 5th wire to the C terminal. This made life easy for me. I bought the Nest from Lowe's so I had that immediately. The Ecobee3 was bought direct a week later and it was 2 day shipping. The Nest had more heft and solid feel. It felt like it was worth the $250 whereas the Ecobee3 is very lightweight plasticy cheap feeling like my existing stat was. It was a bit hard to believe it was more then the Nest. I did have some cosmetic damage on my Ecobee3 and am in the process of exchanging the unit with them. Installation was similar on both. I had 5 wires and both units started right up after I turned the power back on. Ecobee3 has more initial questions than the Nest if I remember correctly. Once setup the Ecobee3 definitely has more things configurable for your HVAC system vs the Nest. The Nest app is smoother to operate. Ecobee3 app is a little clunky but has more settings to customize. Ecobee3 doesn't show the energy savings/usage yet but it says that feature is coming soon. The one thing that really interested me was the remote sensor on the Ecobee3. This stat is on our 2nd floor. We primarily occupy 2 bedrooms and if this thing can average the two rooms to better even out the temperature that would be great. We have tried adjusting the vents but there is still quite a bit of difference. Its a bad time to review these stats right now because my HVAC system isn't really running much. Just a tad at night to keep the house warm. I've decided to keep the Ecobee3 and return the Nest based on the more configurable settings and the remote sensor with comfort in mind.

I wouldn't be too peeved about the media cabinet. The Honeywell one is good (I have the F100), and you may find it easier/less expensive to find replacement filters for it over the Trane PerfectFit media (although nowadays there are plenty of generic replacements, so it may be a wash). On the thermostat: Unless something has changed recently (and I do not believe it has), with your particular set up (XL16i+XV80), you could not do dehumidify on demand (slowing furnace blower speed to remove more moisture) -- one of the capabilities of the IAQ -- anyway due to the way the XL16i is wired to the XV80 (there is a terminal that would be used to the IAQ to signal 80% blower speed; instead this terminal is used by the XL16i to control low stage airflow). On the newer air handlers this has changed so that the dehumidification terminal is available, but to my knowledge the control board on the XV80 is the same. So, in short, no real disadvantage to not having the IAQ. You would only be dehumidifying by overcooling with either one (1-3 deg as set by installer). If Comfort-R is enabled on the furnace, this set up should work quite well, especially having a 2-stage condenser. What additions do you have that you think the IAQ could control? If you have a humidifier, the IAQ can control that, which is nice to be able to have control over the entire system from a single point. So if that is the case, then replacing the 8321 with the IAQ wouldn't be a bad idea. Beyond that, I think all is good, but of course it's your system and your money. Just my 2 cents. This post was edited by ryanhughes on Wed, May 8, 13 at 19:34

bajau for your area/climate/comfort, the main benefit of the HW Vision Pro IAQ is the separate "dehumidify on demand" feature. within certain limits, you can control humidity in your home separate from inside thermostat setting. The HP system will engage on VS blower on low speed to wring out humidity in your home. for example, inside thermostat setting is being maintained but humidity is rising. Your system will activate on blower low speed until humidity drops to setting. if your home is not especially insulated well, then the HW VP IAQ stat is a good choice. Is this stat necessary? absolutely not. your choice. The VP IAQ is more expensive than normal HP stats. There are other brand choices. You do need two separate HP stats to operate two separate systems. IMO

For design temps: Outside: I used avg high/low temps since 2000 from NCDC website which are 99 and 7 but I rounded to 100 and 10. There was typo, I had 105 instead of 100 for summer. Ooops, that might change things! Indoor: Summer temp 68, winter temp 72 and RH 50. New numbers with corrected typo: Gain is 32,632 and loss is same 61,285. I know the âÂÂstandardâ indoor temp setting is 75/68 for summer/winter but that is not realistic for me. Especially in summer. Dealer is very comfortable with 70K, especially with variable speed and referred me to the equipment size guarantee on estimate. Trane quotes with various A/C models (3-Ton) but same XV80 80K furnace: AHRI# 4792315, XL-20: $8,019 net of state tax credit (no Fed tax credit) and utility rebate. AHRI# 5804298, XL-18: $7,365 net of utility rebate. AHRI# 5858127, XL-16: $7,927 net of utility rebate. AHRI# 5806382, XR-17: $7,465 net of utility rebate. AHRI# 5866651, XR-16: $7,767 net of utility rebate. Bryant quotes with 3-ton A/C models and Evolution Plus 80V 88K furnace: AHRI# 6367344, Preferred: $7,466 net of tax and utility rebate. AHRI# 6370090, Evolution: $8,148 net of tax and utility rebate. Same A/C but using Evolution Plus 80V 66K furnace: AHRI# 6367342, Preferred: $7,613 net of tax and utility rebate. AHRI# 6370089, Evolution: $8,195 net of tax and utility rebate. Current system/quote in the lead, Carrier: AHRI# 6405563, Infinity 17 A/C, Infinity 80 variable speed 66K with filter cabinet and Infinity stat: $7,462 net of tax credits and âÂÂrebates.âÂÂ