Thermostat Control to cut down electric bill.

13 Replies

My electric bill during the summers is around $1600/month. It’s already been over $1k/month for the past few months. I’m sure my guests run the AC 24/7. When the doors and windows are open, when they’re gone for the day, etc.

What systems are available for shutting off the AC when nobody is home or if windows or doors are open? I don’t want to monitor it myself, I want it to be automatic.


I use a system called Inthrma, it works great. Tons of features and reporting. It even syncs with my calendar so that I can have different setting when the houses are unoccupied. It is a little expensive to implement, but well worth it. 

Also, with my security system sensors, it knows to turn off the AC if a door or window are left open for more than a couple minutes. 

Let Sam know I referred you if you decide to check it out.

@Kevin Boyd I have never heard of an electric bill that high. You have have your system checked and possibly look for a more efficient system. Geo Thermal is expensive but given what you are paying in utilities might pay for it self rather quickly.

I use Honeywell 9000 wifi thermostats. I can limit the temp range settings. I have mine set so it can't go below 68F. It can be remotely controlled, it will send you alerts if temp or humidity is beyond ranges you set. The honeywell server will also send you alerts if communication is lost with the thermostat.

I have self closing hinges on my exterior doors so someone would have to prop a door open to keep it open.

I have never had anyone leave doors or windows open that I know of. My utility bills are somewhat consistent for the season.

$300 to $400 is a very high electric bill for me even in 90F plus weather.

I have 2 heat pumps, one is a few years old the other was installed this year. 1600SF house.

I love the idea of self closing doors. Unfortunately, this house has 3 sliders to the backyard. The house has a large pool and lots of other outdoor amenities, so we mostly rent to multiple families. I’m sure the kids are in and out all day long and they rarely shut the sliding doors. Also, we’re here in California, so our rates are sky high.

My places are in Florida and I think it is pretty common for people to open windows and crank down the AC. It's crazy but happens. 

I have ecobee at home and love it for my personal house but wanted something a lot more robust for my rentals.

The other thing I did was have my attic insulated with polyurethane. I've only had it for 6 months but based on my inthrma reports, it looks like my AC is running about 25% less. 

I am also considering replacing my crappy single pane windows and sliders with new, high efficiency triple pane glass. It's a huge capital expense but AC is crazy expensive. 

Hi @Kevin Boyd ! Yikes! Have you done an energy analysis to make sure it's the AC and not the pool maybe? San Diego is a pretty nice climate (unless your in Chula Vista maybe) so I would be surprised the AC kicks on so much even with the doors wide open?  To answer your question though, I use a Nest and the Honeywell John mentioned above in my homes.  Nest has actual motion sensors to see if anyone is home and when they are not it puts it into Eco mode.  

Best of luck! 

I've had both NEST and Sensi thermostats.  The NEST works well because it senses when people are not home and you can also lock min/max temps.  The Sensi is a little more basic but I set a schedule for it to reset every 2 hours, so if a guest changes a setting manually, it reverts back after two hours.  I also put the minimum temp at 72, as I've seen guests in the past turn it all the way down to 50!  I recently setup a Google Calendar to email me daily so I can double check them remotely and adjust them accordingly, though this isn't working out very well as it's too much manual intervention.  My places are in Arizona and the highest I've seen is about $250 for month and I thought that was absurd.  You could also consider solar, I did but the power company requires a $50 monthly fee (yep pathetic) for "maintaining the infrastructure" and that kills the financial advantages.

@Sid Payne like to learn more about Intherma, costs and requirements?  Website looks VERY interesting.


@Kevin Boyd when I have traveled in foreign countries I have encountered a key system that is kind of cool. The key used for the door has to be inserted into a wall unit in order to operate lights, etc. So when the key is removed (when you are leaving the unit) the systems are shut down. One place also had motion sensors on lights for staircases and hallways. 

I agree with others, I think that if you don't already have smart themostats it would be a good investment @Kevin Boyd but I somewhat disagree with @Mike Anderson we still have Nest in some units but overall, Ecobee has proven a better experience, for us anyway. 

The Ecobee lite has all the Nest features and fewer drawbacks just in our experience. I'm sure others prefer Nest over Ecobee.

They also make devices that can be wired to shut off the HVAC when certain doors are opened. That may be something worth looking into.  We don't have them but I've seen them implemented, particularly on sliding glass doors.

I, like @John Underwood use the honeywell wifi, I have 3 student rentals ( 5 units in all) with these thermostats. The thermostats are behind a locked metal cover, i provide the internet for the students, but that also allows me to control the thermostats  and on one of the units, the door lock. you can set the schedules and alerts as John mentioned, worth the investment. Are you sure it's the A/C and not the pool, $1600 is a lot, i'm thinking there is something running on the pool that may not have to be, you should have the pool mechanical checked.