Back in September of 2015 I purchased a Nest 3rd Generation Learning Thermostat to replace my programmable Honeywell with the idea that I would review it after a few months and compare the previous year’s electricity and gas bills to the current ones as well as maybe go over what a connected thermostat means in terms of headaches and energy savings.
I was unable to install it myself and it sat for several months until my AC guy came and put it in during routine cleaning.
This is about results and experience, not a features overview.
The Nest 3rd Generation downsides
I’m going to start with the biggest downside I’ve found as this could have been a deal breaker. If your WiFi goes down long enough, or your internet connection gets severed, you’re out one thermostat with no manual way to force heat or cooling on. I had this happen once, fortunately for me it was open-window weather and the fix was to stop testing a broken router.
I do not know if Nest has pushed a firmware update to resolve this yet. I believe the reasoning behind it not allowing you to operate without an internet connection has to do with it will not let you superheat the house when it’s warm outside, and it requires an internet connection to get the temperature rather than being able to rely on a built in sensor on the central unit like my Honeywell did.
The next big downside probably only applies if you live in an older home and are colorblind as a dog. My wiring was not standard and everything had to be traced. It appeared there originally had been a heating system there and a second wire bundle shoved in for cooling sometime in the 80’s. This was not installable by me.
While I’m not a huge fan of app-based configs, I have a ridiculously complex WiFi password. Entering it on the nest was a pain in the booty.
One note on installing – the Nest had lost all charge after the months spent waiting for an AC guy so we got to stand around watching it start charging and talking to Nest support who said it could take up to three hours before it got enough charge to turn on. It came online and was usable about 30 minutes on a wall charger. This was 30 extra minutes I paid for the AC guy’s 10 minute install. Charge your thermostat before the AC guy comes people.
1940’s house, energy savings windows, LED bulbs everywhere, four humans and a cat attempting to live in it. 13 Seer dual-fuel 5-ton? unit from six or seven years ago. During the timeframe work has been going on to seal the drafty basement, some insulation has gone in the walls, and an attempt to make things less drafty old house have been underway.
The Nest was initially programmed with the same temperature parameters as my Honeywell and then told to learn and additionally to use my phone to determine when I’m home.
Because I know how much y’all like numbers I’m going to lead with a set showing about 9 months on the Nest. We’re comparing electricity+gas usage from July 2016-2017 (Nest) to April 2015-2016 (no Nest).
As I don’t have a way (yet. I’m looking at you Sense Home Energy Monitor who said it was shipping last week,) to separate out what’s heating and what’s home electric use, I’m going to guess at a baseline of $70 for other electric use (water heater, fans, tanning beds 1-4, searchlights, hot tubs 1-7, electric helicopter, etc) and subtract that from the electric.
There’s also a monthly membership fee of $14.28 to be a member of the gas club. I’m subtracting that as it doesn’t vary. Therms percentage is taking the Nashville Electric Service number from 2015 and comparing it to 2016/17 – this is a value that the electric service lists based on how hot or cold it was. I’m using work’s spreadsheet on therms for this as I have it handy, and I don’t expect the therms vary that much with 8 miles between work and home.
There’s a few other variables here that during this time there was a new baby around which meant the temperature had to be more stable, having to heat/cool the entire house as opposed to just a bedroom, so factor that into this.
Following is: Month (last year:this year), percentage increase/decrease over last year, Therms percentage increase/decrease, Nest report hours cooling/heating, Nest Leafs.
Apr 2015:2016 $+42%, Therms +4.3% May 2015:2016 $+23%, Therms +21% Jun 2015:2016 $+200%. Therms +46% (bill was indeed double)
Jul 2015:2016 $+51%. Therms +8%, 151 hours cooling (I believe this is when Nest was installed)
Aug 2015:2016 $+58%. Therms -2%, 253 hours cooling , 25 Nest Leafs
Sep 2015:2016 $+59%. Therms +6%, 190 hours cooling, 29 Nest Leafs
Oct 2015:2016 $-27%. Therms +24%, 71 hours cooling, 24 Nest Leafs
Nov 2015:2016 $-12%. Therms +6%, 98 hours heating/cooling, 29 Nest Leafs
Dec 2015:2016 $+63%. Therms +13%, 177 hours heating, 23 Nest Leafs (130 for the year)
Jan:2017:2016 $+28%. Therms +33%, 146 hours heating, 22 Nest Leafs
Feb 2017:2016 $-35%. Therms -9% , 100 hours heating, 22 Nest Leafs
Mar 2017:2016 (waiting on gas bill), 63 hours heating, 26 Nest Leafs
I’ll try and update this as I get in more bills.
Oh, bottom line, no dollar or electric savings at all however it was a much hotter year.
The road bumps
One of the things I discovered along the way was that the Nest app was complaining that my phone was reporting an incorrect location and that it didn’t know when I was actually home.
It was also assuming I was home when I was at work sometimes. That appeared to be related to it using the IP on the internet connection to determine where I was as opposed to using course location or GPS. When you use a VPN that doesn’t allow you to skip certain programs, I think this happens.
As such I don’t think the Nest was actually learning in the beginning and was assuming I was home all the time. I think it’s working now as I haven’t seen that error message that it can’t figure out where I’m at in a couple of releases of the app.
When the app was tracking me and for some reason the wife or kids were home, they’d suddenly realize it was getting hotter or colder and have to modify the temp. No big, but something to think about if your loved one is sick in bed and you’re walking out of the house. You’ll be freezing or boiling them out of bed fairly quickly unless they have the app on their phone or you remember to set it remotely.
The squishy purely “Paul thinks this” part
While cash I’ve spent on utilities looks otherwise, I think this is working. Just not a dramatically reduced rate due to already having it set fairly close to what the Nest has learned.
Being able to remotely turn the AC or heat off can save a significant amount, and when the thing that figures out if you’re home or not kicks in and works (which it seems to have been doing lately,) it’s nice. It’s pleasing to walk in and the house is about right all around.
Hooking it into Alexa and Google Home has been fairly useful also. Rather than Kim telling me to change the temperature she can tell whichever voice assistant is nearby without pausing whatever show we’re watching.
Mostly yes. I think this coming year I’m going to start seeing savings. I also think if I had a test house to compare against I’d probably see the cost of the Nest 3rd Generation thermostat paid back by now. Having a baby, more time home, hotter year, etc have skewed results.