Make a dumb thermostat smart, sorta


(Glen King) #1

I have two thermostats. Downstairs zone is serviced by the Ecobee4. Upstairs by a programmable, unconnected thermostat. Upstairs zone does only AC, no heat there… and the thermostat runs on battery.

Early this morning, as the outdoor temps were in the midst of a 30 degree change, I had the scenario where ecobee had the heat on for downstairs while AC was on upstairs. Wife woke overheated at 4am and turned down the thermostat in order to turn on AC, while downstairs was cold so the heat went on.

I want to configure things so that if the upstairs AC goes on, the downstairs heat will not go on.

If it can be done with current configuration, that might work. Webcore will be the vehicle: whatever device config I use will tell webcore the upstairs AC is on, and thereby set ecobee to a setting where it can’t trigger the heat on. Perhaps a power meter on the upstairs AC unit. Or perhaps there exists a battery operated ST compatible thermostat. Or perhaps something I’ve not yet considered… any ideas??


(Ron Talley) #2

If me, I would slap some type of power meter on the AC or maybe a temp sensor right where the cool air blows out…

The power meter would definitely tell you when the AC is on.

The temp sensor would be less reliable but that air coming out of the AC should be about 20 degree cooler than the room temp…


(jeubanks) #3

What kind of AC? Sounds like it’s not a central unit. Does it have a plug like a window unit or a stand alone or is it hard wired?


(Glen King) #4

Upstairs zone… thermostat… Standalone ACs don’t need thermostat control, they have their own sensors and controls built-in. In other words, yes it’s a central unit. Runs on 220v.


(jeubanks) #5

No, not all standalone units have their own sensors built in. I’ve got 4 of them that don’t which I’ve built my own virtual thermostat system for. Do I bother ask about the thermostat or should i know already because it runs on batteries?


(Enis Hoca) #6

+1 to @jeubanks suggestion - roll your own. get a nodemcu or webmos mini, and a dht22 or ds18b20 - its simply connecting or soldering 5 wires and get the data using ST_Anything.


(Glen King) #7

I’ve never seen a window or floor standing AC that plugs into a standard 120v electrical outlet that does not have a dial where you set the cooling level, and when the environment reaches that temperature the AC stops cooling.

Guess I need to get out more. Or get in more.
Or something.


(Ernie) #8

The CT101 is a z-wave thermostat that runs on batteries and is compatible with ST. It has no internal programming of schedules and is fully dependent on a z-wave hub or manual input to change its settings. It can be programmed by routines, WebCore and other smartapps.


#9

This is what I use. I have 3 of them (one on each floor) hooked to a central ac / gas unit. I use webcore for scheduling and for “fancy” stuff like turn off the main floor thermostat if a window is open.


#10

If nobody is home and SmartThings goes down (never happens right? Lol), how do you control your thermostats remotely? Turning the heat or cooling off in the event that one of your Automations begins heating/cooling the house, but the ST cloud goes down or the ST app is unavailable and is unable to shut off the thermostat? Are there fail safes built in? Is there another app that you are able to control the thermostat from? Just looking at what the plan b is when you are depending on ST for 100% of this functionality and automation :slight_smile:


(Ernie) #11

You can not control it remotely without ST. However, the thermostat retains the last set of settings it received. Therefore if you set the ac to 72, it will cool until it reaches that temperature and then it will shutoff. It will continue to turn itself on and off to maintain the temperature at 72 like another thermostat until its settings are changed manually or by ST. Below is a photo of the dh I use with my CT101.


(jeubanks) #12

@Glen_King, yes most have dials. The 4 I use have two dials. 1 for low/high fan and low/high cool and another that goes from 1-7 for low/high cool. I can tell you that with all four units it doesn’t matter what that “cooling” dial is set to. It could be 1 or 7 and they will run forever. Could be faulty units… but four of them? I have them in the bedrooms and I didn’t have my daughters added into the system last night and it ran all night long and all day today until I got it added.