I have a great Waterfurnace Transquility 27 5 ton system (not zoned) with a 7 200 ft trenches (WEL0413). I trialed a Nest 2.0 for a while. I think it is a great thermostat for the masses on gas heat however it's logic for geothermal was awful. It very quickly went to stage 2 even with mild outside temperatures. So I went to the Ecobee Smart. Very easy install and the system has an amzing amount of customability. What is the optimal setup? I know no configuration is perfect however what are the general principles I should use? Here is how I am configured thus far. Minimum heat run time: 10 minutes (to get a good, efficient run) Minimum compressor off time: 10 minutes (in severe settings may result in some temperature drift, but house is pretty tight, want to avoid rapid cycling) Temperature delta 1.0dF I'm using reverse staging with a temperature band. So the system starts in stage 1 and runs stage 1 until the temperature in the house drifts down 3 dF below the set point, (so if house is set for 73 as I understand it the Ecobee will not activate Stage 2 unless the home temp drifts below 70.0) and Aux heat is set for 5dF delta. So far even with colder than typical conditions I see long stage 1 runs (up to 45 minutes on, 15 off) during the coldest of the night, of course all in stage 1 with good comfort. Is this a good config? Longer run times should be easier on the equipment, longer in stage 1 should improve efficiency correct? Can you have TOO long of run times in stage 1 as long as comfort isn't effected?

Can you have TOO long of run times in stage 1 as long as comfort isn't effected? Not in my Book.

Posted By geodean on 23 Dec 2013 08:01 PM
Can you have TOO long of run times in stage 1 as long as comfort isn't effected? Not in my Book.

Thought after reading a lot of data it does appear the COP and EER change on my 049 (5 ton) climate master when you go from partial load to full load (stage 1 to stage 2) is relatively small at real world EWTs. The EER change is a bit more significant but both are relatively small overall, so I am probably going to have to use the Ecobee for a long time in order to pay back the $250.

First, as you point out the savings by staying in first stage versus going for the comfort of less droop is nominal, so be comfortable.
Second if that is all you are using your ecobee for then yes, you shouldn't have bought it. My clients enjoy them for the email if auxiliary is running too much (which could easily cost you more than $250 in just a few weeks) and other notifications. They also enjoy access from anywhere in the world, and the logging it does in the excel spreadsheets....etc
You could have set up a $50 stat to do what you wanted if none of the other ecobee features appeal to you.

Posted By joe.ami on 24 Dec 2013 10:22 AM
First, as you point out the savings by staying in first stage versus going for the comfort of less droop is nominal, so be comfortable.
Second if that is all you are using your ecobee for then yes, you shouldn't have bought it. My clients enjoy them for the email if auxiliary is running too much (which could easily cost you more than $250 in just a few weeks) and other notifications. They also enjoy access from anywhere in the world, and the logging it does in the excel spreadsheets....etc
You could have set up a $50 stat to do what you wanted if none of the other ecobee features appeal to you.

For me that is part of the benefit as well. 1) I enjoyed installing it and it certainly will be more reliable than the issues I had with the "power stealing" tricks of the Nest 2.0 2) My Nest was VERY quick to go to Aux heat even in relatively minor conditions so the savings will likely come from eliminating this effect. I have email notifications for Aux use as well 3) Being able to control humidity (Honeywell Trusteam) from the Ecobee will be nice versus the on furnace controller I have now. I just need to wire that up. 4) Ecobee is geeky. I love that! I did my own entire Welserver install too to instrument my system so you can tell I like having data!

It would be interesting to know your worse case heat up and cool down rates. For example, in very mild weather, how much does the temperature rise with 10 minutes of run-time? Perhaps too much.