Smart thermostat savings?

[reader2580]

I had one from the power company as well a while back. Same principle, they wanted to control the AC on really cold days. Turned out to be a bit of a flop, and they cancelled the program. I got rid of their thermostat. It wasn't very good, but the WiFi control was nice to have when it did work.

Why would they want to turn off your A/C on a really cold day?

I doubt the electric CO-OP here will be cancelling this program any time soon. I believe after the first season I own the thermostat outright even if I drop out of the program. It is a pretty decent thermostat that I would keep if I wanted to drop out.

They also have a dual fuel program for heating, but it uses a separate meter and a radio receiver. The previous owners of this house were on that program, but they were still spending $3,500 a year on electricity. (They didn't actually have a second source of heat.) I converted to natural gas and had the extra electrical equipment removed. I now spend about $1,300 a year for gas and electric.

 

[MUD DAWG]

Why would they want to turn off your A/C on a really cold day?

I doubt the electric CO-OP here will be cancelling this program any time soon. I believe after the first season I own the thermostat outright even if I drop out of the program. It is a pretty decent thermostat that I would keep if I wanted to drop out.

They also have a dual fuel program for heating, but it uses a separate meter and a radio receiver. The previous owners of this house were on that program, but they were still spending $3,500 a year on electricity. (They didn't actually have a second source of heat.) I converted to natural gas and had the extra electrical equipment removed. I now spend about $1,300 a year for gas and electric.

Ooops, sorry, they turned it off (actually increased the temp), on hot and humid days to lower peak demands.

The thermostat was OK. When the program was over, they let everyone just keep it, but shut off the WiFi function, and on top of that, it didn't support my 2 stage furnace. I took it out and installed the better Honeywell. Our electricity system has been plagued with scandals, and incredibly dumb moves by the government that has cost us billions and billions. The failure of this thermostat program wasn't much of a surprise unfortunately.

You did the right thing by converting to natural gas. I wish I had access to NG in my area. I'd convert in a heartbeat, and would switch the stove and water heater as well, and I'd even buy a NG backup generator.

 

[jhelrey]

I keep mine at a constant 68*. I have no need or desire to adjust it when I leave for work or come home, etc.

 

[Falcon67]

I'm interested in hearing the pros and cons of each product's WiFi support. Want to monitor temps in house while we're away for two months. Thanks!

Ecobee has an app for the phone and you can also log into the web site to control the unit. The pro for me is that it keep a fair amount of data. No con. Easy to set up - it found the PSK network in the house without being told the SSID and just took the password and ran with it. No muss, no fuss.

 

[garagelogician]

Yeah, seriously, we're just talking about a damn thermostat here




Yup that'll be fun playing ghost with them.

Here's another situation that I think a WiFi thermostat could come in handy. We got home late last night, to find out the furnace hasn't kicked on for hours, and the house was ****** freezing. I just had a brand new high eff. furnace installed, and one of the pressure switch hoses had popped off. I'm thinking with a WiFi thermostat, if we're away for an extended period of time, it'll let me keep an eye on things, and eventually I might ask a neighbor to pop over and have a look. It would be cool if the thermostat would send me an alert if the house got too cold, but I haven't seen any of the thermostats mention this fact.

Ecobee lets you set thresholds for high temp and low temp alert. The app will notify you and you can also have it send you an email.

We really like our Ecobee, and it is far superior to the Nest or any other WiFi thermostat. What is really nice is the additional sensors you can add, and all the customization options. We use the extra sensor in our upstairs master bedroom (you could add multiple sensors and average them if you have multiple occupied bedrooms) so that only the temperature in that room controls the HVAC at night. It costs us a little more in the summer with A/C (due to internal gains and such), but we are more comfortable. It saves us a ton of heating hours in the winter though because the rest of the house can get colder while our bedroom maintains 64. The furnace barely ever runs at night (only once or twice on the coldest nights), but it knows when to turn on the heat in the morning so that the rest of the house is warm when we get up. A nice side effect of this is that the bedroom and upstairs bathrooms get a little extra toasty early in the morning while the rest of the house comes up to temp, which is nice to wake up to.

The geofencing feature does need some work, we have found it a little buggy and not very intutive...but this is something I think they are continuing to work on and should be able to be fixed with software updates. We aren't able to use the sensor-based smart home/away because our big dogs set off the occupancy sensors, so when the geofence works, its great.

Payback period was about 12 months (per Ecobee's estimation), but should have been better than that because we had a failing A/C unit that was running constantly for about 3 months.

 

[u3b3rg33k]

Daily setbacks done perfectly can save about 10%. You really have to look at what the thermostat manufacturers are talking about when they say savings of 20+ percent. Many lower the overall house temp -- making a case for tighter controls allowing for lower overall temp setting. It's going to cost less to maintain 68 vs 72.

If you use a heat pump -- be very careful about setbacks.

We basically maintain tight temps (home office) .. allowing for the highest temps in the evening and then a slow drop till morning .. with a smaller bump for a very short time in the early AM. It takes a long time for our house to drop 3 degrees.

I love both our carrier and Honeywell internet thermostats -- with vacation properties its easy to monitor the spaces and turn the units up way in advance. We previously had typical systems that mimicked our usual schedule -- I can now keep both places much lower now w/o fear of having an uncomfortable house when we arrive. The savings come when you can drop the temps for days or a week.

the good high end thermostats can be told to do "intelligent recovery" for setbacks with heatpumps (start earlier due to longer time required to heat up) so they don't engage backup heat. or you can lock-out backup heat based on indoor or outdoor temp (i.e. no backup heat allowed over 10F outdoor temp, or must be 15F below setpoint to allow backup heat, etc).
Even if your heatpump can't keep up and you need aux heat to fill in, it's likely true that the BTU from the heat pump are still cheaper than the aux strips.

 

[aunsafe2015]

the good high end thermostats can be told to do "intelligent recovery" for setbacks with heatpumps (start earlier due to longer time required to heat up) so they don't engage backup heat. or you can lock-out backup heat based on indoor or outdoor temp (i.e. no backup heat allowed over 10F outdoor temp, or must be 15F below setpoint to allow backup heat, etc).
Even if your heatpump can't keep up and you need aux heat to fill in, it's likely true that the BTU from the heat pump are still cheaper than the aux strips.

So are setbacks with heat pumps a good idea as long as backup/auxillary heat does not engage when bringing back to to normal temperature?

Any idea whether you'd be better off jumping from say, 66 degrees straight to 70, or would you be better off having your thermostat go up 1 degree every 30 minutes or something like that to keep your heat pump operating at the lower stages?

 

[PT Doc]

If saving a few dollars is more important than being comfortable then drop the temp in the winter and wear a sweater. 5 degree drop seems like a lot. I would rather be comfortable. Low speed fan runs regularly to keep the temps even but this is a function of the furnace. Spending $200 with the hopes of savings a few bucks here and there doesn't seem like a good return. Look at the programming and make adjustments there. That is free and money in you pocket right away. Insulate the attic to r60 and that will pay back right away.

 

[u3b3rg33k]

So are setbacks with heat pumps a good idea as long as backup/auxillary heat does not engage when bringing back to to normal temperature?

Any idea whether you'd be better off jumping from say, 66 degrees straight to 70, or would you be better off having your thermostat go up 1 degree every 30 minutes or something like that to keep your heat pump operating at the lower stages?

if you don't use aux heat (COP 1), then you get your rated COP for whatever outdoor temperature you're dealing with (call it COP of 3.0). that's 66% savings for the same heat delivered. you can "cheat" by setting your thermostat to work around however it's programmed to operate, IF the outdoor conditions allow.

Setbacks with heatpumps were never a bad idea. Setbacks with thermostats that turn on super expensive (heat strips) backup heat are a bad idea. poor controls do not make heat pumps a bad source of heat - but they do give them a bad rep!

If saving a few dollars is more important than being comfortable then drop the temp in the winter and wear a sweater. 5 degree drop seems like a lot. I would rather be comfortable. Low speed fan runs regularly to keep the temps even but this is a function of the furnace. Spending $200 with the hopes of savings a few bucks here and there doesn't seem like a good return. Look at the programming and make adjustments there. That is free and money in you pocket right away. Insulate the attic to r60 and that will pay back right away.

I opted int to time-of-use power where I live, and like it cold while I sleep (4F setback), and I like it 40F in my garage in the morning. Due to setting my thermostat up to take advantage of ToU, I save about 15% a month on my electric bill vs flat pricing.

In some areas of the country without NG service, that $200 thermostat can have a simple payback of as little as one month by minimizing the use of backup heat. reducing aux heat can literally knock your useage down to half or better (say, from 4000kWh to 2000kWh in a month). $800 bills ****.

And of course, If you set it up wrong, you can end up costing yourself more money.

 

[Falcon67]

So are setbacks with heat pumps a good idea as long as backup/auxillary heat does not engage when bringing back to to normal temperature?

As I noted earlier the Ecobee allows you to program the Delta that will trigger Aux heat. The Honeywell that I junked was fixed at 2F. I set the Ecobee at 5F.

https://support.ecobee.com/hc/en-us...Minimize-use-of-Auxiliary-Heat-with-Heat-pump

 

[yeldogt]

the good high end thermostats can be told to do "intelligent recovery" for setbacks with heatpumps (start earlier due to longer time required to heat up) so they don't engage backup heat. or you can lock-out backup heat based on indoor or outdoor temp (i.e. no backup heat allowed over 10F outdoor temp, or must be 15F below setpoint to allow backup heat, etc).
Even if your heatpump can't keep up and you need aux heat to fill in, it's likely true that the BTU from the heat pump are still cheaper than the aux strips.

Yes .. but it's all a question of the systems capacity ... Variable speed HP's are not equal in efficiency throughout the range and single speed HP's obviously only have one setting. It's a question of how much are you really going to save -- to give up a level of comfort. Do I want a VS HP that would normally drop 3 degrees when running in stage 2 and then moving to stage 3 to regain temp in the morning .. or do I want it to go to 5 and be outside it's efficiency curve to recover from a 8 degree set back?

The nice thing about the eccobee -- it's using intelligence to overcome what is typically very poorly designed HVAC systems. Even using combined sensors from various parts of the house is a big help -- they increase comfort.

 

[u3b3rg33k]

Yes .. but it's all a question of the systems capacity ... Variable speed HP's are not equal in efficiency throughout the range and single speed HP's obviously only have one setting. It's a question of how much are you really going to save -- to give up a level of comfort. Do I want a VS HP that would normally drop 3 degrees when running in stage 2 and then moving to stage 3 to regain temp in the morning .. or do I want it to go to 5 and be outside it's efficiency curve to recover from a 8 degree set back?

The nice thing about the eccobee -- it's using intelligence to overcome what is typically very poorly designed HVAC systems. Even using combined sensors from various parts of the house is a big help -- they increase comfort.

That all depends on the outdoor conditions and the system in question. IIRC the intelligent recovery honeywell models will reduce your setback automatically if they won't be able to recover - so if it's extra cold out, your 8F setback might become 4F setback. Honestly I don't care if the heat has to come on an hour or two earlier to meet my setpoint by the time I wake up - I'm sleeping!
The honeywell I like lets you control HP staging separately from aux staging - so you can be aggressive with the heat pump but conservative with aux heat. I think the biggest savings come from avoiding aux heat when it's just not needed - temperate weather where you have more than adequate capacity. Lots of the newer systems don't need aux heat above 15-20F, maybe lower if you have an inverter system like the Bosch where it monitors system temp/pressure to control the compressor to give it a boost in the cold/add efficiency when it's warm (and vice versa for cooling season).

I don't use setback during heating season to save money at night - i use it to add comfort. that it saves me money is just a bonus.

I've only seen a single VS gear controllable by a standard thermostat (the bosch inverter line, and all it has is on/off from the stat) - all of those I've seen use manufacturer supplied communicating stats. Some of the specs for staged gear state that they're not any more efficient in stage 1 over stage 2 - likely due to cheaper motors (not ECM fans).

That bosch system is pretty cool - appears to be able to adjust itself from about 20-120% capacity based on monitoring head/suction temp/pressure. it'd probably be the system to choose if zoning a heatpump install, or retrofitting a poor install (undersized ducts, undersized coil, etc).

 

[yeldogt]

That all depends on the outdoor conditions and the system in question. IIRC the intelligent recovery honeywell models will reduce your setback automatically if they won't be able to recover - so if it's extra cold out, your 8F setback might become 4F setback. Honestly I don't care if the heat has to come on an hour or two earlier to meet my setpoint by the time I wake up - I'm sleeping!
The honeywell I like lets you control HP staging separately from aux staging - so you can be aggressive with the heat pump but conservative with aux heat. I think the biggest savings come from avoiding aux heat when it's just not needed - temperate weather where you have more than adequate capacity. Lots of the newer systems don't need aux heat above 15-20F, maybe lower if you have an inverter system like the Bosch where it monitors system temp/pressure to control the compressor to give it a boost in the cold/add efficiency when it's warm (and vice versa for cooling season).

I don't use setback during heating season to save money at night - i use it to add comfort. that it saves me money is just a bonus.

I've only seen a single VS gear controllable by a standard thermostat (the bosch inverter line, and all it has is on/off from the stat) - all of those I've seen use manufacturer supplied communicating stats. Some of the specs for staged gear state that they're not any more efficient in stage 1 over stage 2 - likely due to cheaper motors (not ECM fans).

That bosch system is pretty cool - appears to be able to adjust itself from about 20-120% capacity based on monitoring head/suction temp/pressure. it'd probably be the system to choose if zoning a heatpump install, or retrofitting a poor install (undersized ducts, undersized coil, etc).

My newest Carrier 5 stage does not even have a back up -- and the hyper heat mini splits don't have them. We like a warm house -- and windows .... so we don't do a huge setback when there.

Non of this stuff works together -- it's is cool that you can now add this type of control to a dumb system for only a few hundred dollars.