4 ms·

It is very unlikely that this is accurate, or there are substantial externals that are not being accounted for (e.g. stopping using a desktop as much as a table

It is very unlikely that this is accurate, or there are substantial externals that are not being accounted for (e.g. stopping using a desktop as much as a tablet gets heavy usage) -- the difference between 2012-01-01 and 2013-01-01 is just way beyond what even the biggest Nest hyper claims. Outside of savings that grossly exceed even the best expectations, when questioned whether they used a programmable thermostat already (the absolute bog standard $20 variety automatically dropping the temperature in a manner that is close to optimal for about 95% of people), the author gave a very wishy-washy answer that didn't actually answer the question.

mjn 13y ago
Heck, I didn't have a programmable thermostat for three years, in Atlanta, and would be surprised to see anywhere near these savings. I had a thermostat with a manual lever, which was mechanically coupled to a mercury-glass switch that controlled the A/C (this was a new apartment building built in 1999, strangely enough, not some ancient relic). I turned the thermostat way up (i.e. reduced the intensity of the A/C) when I would leave, and turned it back down when I got home. This by itself was enough to reduce almost to zero the operation of the A/C when I wasn't home, which was a pretty good approximation of the desired outcome.
smoyer 13y ago
I agree ... And the thing I noticed is that during the cold snap (which wasn't nearly as long but was just as cold), they hardly used any power compared to the previous year. Perhaps they wer on vacation? I think "occupied hours" would be pretty important for these measurements. And if you multiplied occupied hours times the inside-outside temperature differential, you'd (maybe) start to see some patterns.
ars 13y ago
Is this nest controlling an A/C or a heater? Or both? Do they really use electric heat? The graph doesn't make sense.
- fnordfnordfnord 13y ago
  Some people use electric heat in the south. Mine is gas, but I wouldn't mind electric since I use it only a few weeks per year.
  - deleted 13y ago
    [deleted]
- willyt 13y ago
  It's a convention of building physics to convert all energy useage to kW (sometimes BTU in the US) regardless of whether its gas, electric, oil, biomass etc. For example, Passivhaus calcs are done this way.
MrFoof 13y ago
I've been a Nest user since nearly Day 1, and about 19 months now overall. At this point I've probably recouped about 80% of the price of the thermostat, with my electric bill reduced by about $10-11/month ($55-65/mo to $45-55/mo) for a 725 sqft luxury apartment. I should probably write a blog post with all the details, but here's my take: * I have a south-facing apartment with about 110-square feet of window glass. It heats up like a sonofa in the morning. I was able to counter this by setting a warmer limit for cooling in the summer. The blinds were always correctly set every evening to minimize summer cooling and winter heating. * The leaf stuck out at me. I always wondered "why can't I get the leaf with my setting -- what do I have to adjust it to to get the leaf to appear?" This resulted in behavioral changes such as wearing different clothes, and taking better advantage of the windows to make getting the leaf to appear achievable. * Once I hit the leaf, I then looked into other ways to maintain comfort, particularly in the summer. I've since invested in a fan to eliminate the envelope of heat that surrounds my body. Running the fan 20 hours a day is equivalent to running the A/C for 20-25 minutes, which is a big savings if I can eliminate 2.5 to 3 hours of A/C usage a day (at 18.5 cents/kWh). With the addition of the fan, and finally finding some LED light bulbs with the right lens type and color temp (to replace some halogens in the track lighting), my electric bill was $42 for July, despite the ridiculous northeast heat wave. Despite constant 90+ degree temperatures and high humidity, I was able to get by with about 1 hour and 15 minutes of A/C a day, and didn't feel bad about it.
- TylerE 13y ago
  Yes, that's kinda the thing though. If you're going to lifehack your way out of it, that's an externality.
  - Corrado 13y ago
    I'm not sure I agree. If the Nest helps to change your habits then I would consider it a net win. It doesn't really matter how you saved the money, just that the Nest is paying for itself. Sort of like paying Weight Watchers to help you stick to your diet. :)
    - 13y ago
Steko 13y ago
"the difference between 2012-01-01 and 2013-01-01 is just way beyond what even the biggest Nest hyper claims" Doesn't the temperature chart explain most of the savings? A colder winter and hotter summer for the first year (pre-Nest). The simple total of net degrees by month disguises the fact that the second year is much milder. What you want to look at is KWH from months (days if possible) with nearly identical avg temperatures, come up with composite "savings" for different month types and project that on a year.
- ics 13y ago
  Below are the charts for each period. My attention isn't here but if someone with some statistical know-how wants to give even a casual analysis it would be interesting. Pre-Nest: http://www.wunderground.com/history/airport/KDTO/2011/7/1/CustomHistory.html?dayend=1&monthend=7&yearend=2012&req_city=NA&req_state=NA&req_statename=NA http://www.wunderground.com/history/airport/KDTO/2011/7/1/Cu... Nest: http://www.wunderground.com/history/airport/KDTO/2012/7/1/CustomHistory.html?dayend=1&monthend=7&yearend=2013&req_city=NA&req_state=NA&req_statename=NA http://www.wunderground.com/history/airport/KDTO/2012/7/1/Cu...

mjn 13y ago

Heck, I didn't have a programmable thermostat for three years, in Atlanta, and would be surprised to see anywhere near these savings. I had a thermostat with a manual lever, which was mechanically coupled to a mercury-glass switch that controlled the A/C (this was a new apartment building built in 1999, strangely enough, not some ancient relic). I turned the thermostat way up (i.e. reduced the intensity of the A/C) when I would leave, and turned it back down when I got home. This by itself was enough to reduce almost to zero the operation of the A/C when I wasn't home, which was a pretty good approximation of the desired outcome.

smoyer 13y ago

I agree ... And the thing I noticed is that during the cold snap (which wasn't nearly as long but was just as cold), they hardly used any power compared to the previous year. Perhaps they wer on vacation? I think "occupied hours" would be pretty important for these measurements. And if you multiplied occupied hours times the inside-outside temperature differential, you'd (maybe) start to see some patterns.

ars 13y ago

Is this nest controlling an A/C or a heater? Or both? Do they really use electric heat? The graph doesn't make sense.

fnordfnordfnord 13y ago
Some people use electric heat in the south. Mine is gas, but I wouldn't mind electric since I use it only a few weeks per year.
- deleted 13y ago
  [deleted]
willyt 13y ago
It's a convention of building physics to convert all energy useage to kW (sometimes BTU in the US) regardless of whether its gas, electric, oil, biomass etc. For example, Passivhaus calcs are done this way.

MrFoof 13y ago

I've been a Nest user since nearly Day 1, and about 19 months now overall. At this point I've probably recouped about 80% of the price of the thermostat, with my electric bill reduced by about $10-11/month ($55-65/mo to $45-55/mo) for a 725 sqft luxury apartment. I should probably write a blog post with all the details, but here's my take: * I have a south-facing apartment with about 110-square feet of window glass. It heats up like a sonofa in the morning. I was able to counter this by setting a warmer limit for cooling in the summer. The blinds were always correctly set every evening to minimize summer cooling and winter heating. * The leaf stuck out at me. I always wondered "why can't I get the leaf with my setting -- what do I have to adjust it to to get the leaf to appear?" This resulted in behavioral changes such as wearing different clothes, and taking better advantage of the windows to make getting the leaf to appear achievable. * Once I hit the leaf, I then looked into other ways to maintain comfort, particularly in the summer. I've since invested in a fan to eliminate the envelope of heat that surrounds my body. Running the fan 20 hours a day is equivalent to running the A/C for 20-25 minutes, which is a big savings if I can eliminate 2.5 to 3 hours of A/C usage a day (at 18.5 cents/kWh). With the addition of the fan, and finally finding some LED light bulbs with the right lens type and color temp (to replace some halogens in the track lighting), my electric bill was $42 for July, despite the ridiculous northeast heat wave. Despite constant 90+ degree temperatures and high humidity, I was able to get by with about 1 hour and 15 minutes of A/C a day, and didn't feel bad about it.

TylerE 13y ago
Yes, that's kinda the thing though. If you're going to lifehack your way out of it, that's an externality.
- Corrado 13y ago
  I'm not sure I agree. If the Nest helps to change your habits then I would consider it a net win. It doesn't really matter how you saved the money, just that the Nest is paying for itself. Sort of like paying Weight Watchers to help you stick to your diet. :)
  - 13y ago

Steko 13y ago

"the difference between 2012-01-01 and 2013-01-01 is just way beyond what even the biggest Nest hyper claims" Doesn't the temperature chart explain most of the savings? A colder winter and hotter summer for the first year (pre-Nest). The simple total of net degrees by month disguises the fact that the second year is much milder. What you want to look at is KWH from months (days if possible) with nearly identical avg temperatures, come up with composite "savings" for different month types and project that on a year.

ics 13y ago
Below are the charts for each period. My attention isn't here but if someone with some statistical know-how wants to give even a casual analysis it would be interesting. Pre-Nest: http://www.wunderground.com/history/airport/KDTO/2011/7/1/CustomHistory.html?dayend=1&monthend=7&yearend=2012&req_city=NA&req_state=NA&req_statename=NA http://www.wunderground.com/history/airport/KDTO/2011/7/1/Cu... Nest: http://www.wunderground.com/history/airport/KDTO/2012/7/1/CustomHistory.html?dayend=1&monthend=7&yearend=2013&req_city=NA&req_state=NA&req_statename=NA http://www.wunderground.com/history/airport/KDTO/2012/7/1/Cu...