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'm trying to figure out how to reply to each response but I'm just not seeing it so. Thanks Steve for the formula. jreagan this is a bare bones AC transformer that needs an enclosure and maybe a ground somewhere. That brings me to the power cord that has 3 wires. I was hoping for a simpler solution like a RadioShack device with built in plastic case. dennisgli this link shows something like what I have. Model Number PF42440 Home Depot http://www.homedepot.com/p/Packard-40VA-120-20-240-Volt-24-Volt-Secondary-2-ft-Mount-Transformer-PF42440/203565058?N=5yc1vZc4nlZbae

The color temperature isn't as important as the actual ratings of the bulb. The "alleged" wattage equivalent is pure marketing tripe. Somewhere in the fine print will be lumens.

It appears you have wired the new thermostat correctly. How long does the blower run before the condenser kicks in? How long are you waiting between attempts of lowering the thermostat temperature in order to start the condenser? What might be happening in the new thermostat is the the G terminal is energized immediately which turns on the blower, and the Y terminal has a delay and energizes after a period of time. On most furnace control boards the Y terminal also turns on the blower. So as an experiment try disconnecting the G terminal and then lower the thermostat enough to turn on the AC. The blower and condenser should turn on at the same time. The clunking you hear is probably the condenser contractor closing. I don't see how changing the thermostat would affect the noise level.