Pseudo Heating Zone

[witoldw]

HomeSeer Newbie here.
I'm looking for an elegant (or hacky, either is fine) way to add a pseudo-heating zone.

Our upstairs has a couple heating zones, however the thermostat is on the east side of the house and my son's bedroom is on the west side of the house. For whatever reason, his room tends to be much cooler overnight.

All my thermostats are zwave and already on the system. What I want to do is put a Z-Wave temperature reporting device into my son's room, and have it warm the room to a set point. Basically slave the thermostat on the other side of the house to the temperature reporting device in my son's room.

Is that possible? If so can you suggest a series of events that could be strung together to make this work?

I initial thought was to have a event that triggered based on the temperature of the device being below a set point, and that would raise the set point of the thermostat that controlled the heater to a much higher level.

After the set point is reached, I I could then reset the thermostat to the lower setting.

Is that the best way to do it?

Thanks for any ideas.

[mulu]

Does your thermostat allow a second sensor? If so I would place a second sensor into your son's room. Since it is all the way on the other side you probably have to go into the attic or crawlspace. If it doesn't allow a second sensor then, as you said, get a (z-wave) device that can read temperature and place it in your son's room. HS happens to have a sale tomorrow of their HSM200 multi sensor device. Since the room is only much cooler during night time use an event that starts for instance an hour after sunset. In that event you can increase the setpoint by the difference of your desired temperature and the temperature in your son's room. Then in the morning you switch back to the previous value.

[enigmatheatre]

You want to install the SVJ-VStat plugin and use this as a virtual stat for control.

[dbvanb]

I had a similar problem (but not quite the same).

I got new air conditioners (upstairs and downstairs) several years ago, American Standard, with communicating thermostats. So no option of changing those thermostats to something else. But they would only control the cooling system, which uses forced air. They told me to leave a second thermostat right next to theirs to control the hot water baseboard heat, which was not their system. Not really good looking. After, I argued with them and got an extra relay device from their company, it would control my hydronic system for heat, but I could not turn off the fan when it was heating (not a choice available in their program). This was obviously not needed for the hot water system, and in the winter would blow cool air.

So, I rigged up my own virtual thermostat. I created a thermostat device in homeseer (not easy - possibly SVJ-VStat would be better, and I looked at it. Just didn't seem to work for me). Then I hooked up a relay in parallel with the other thermostat wires to energize the selenoid to open the water valve for that zone. This is controlled with a raspberry pi GPIO pin (the pi also senses the temperature in all the individual zones, as well as other sensors - ie attic and crawl space temperatures and humidity). Then using RaspberryIO plugin by Spud to control the GPIO on the raspberry pi, I now have a thermostat. It then required a script to use the value of other sensors in the room to control the virtual thermostat

To make it even more simple - these sensors use an ESP8266 controller and a AM2302 sending mqtt messages to mcsMQTT plugin in HomeSeer. I have to say that all the zone temps and humidity values are also sent by mqtt. I also have other things that send mqtt messages. I leave the American Standard thermostat set low as a backup.

All of this to get around a company that would not do a little programming for me (or others I suppose) to have an off mode for the fan. The American Standard themostat is a touch screen, which runs embedded linux, but it is completely locked down as well.

I still have two touch pads next to each other. The American Standard thermostat and a Fire tablet with Fully Kiosk and HSMetro as an interface to all of Homeseer devices and other things.

It didn't seem so complicated, until I wrote it down here, but actually works quite well.

Bruce

[witoldw]

Thanks everyone for the great ideas.

dbvanb, you sir, are a man after my own heart. Building an entire sensor stack to get around a stupid mfg limitation.

mulu, Thank you. I think this is the way I'll end up going. I've been experimenting over the past couple of days to see what works, and I used an existing Zwave device that reports temperature. Its one of those zwave motion sensors from monoprice that everyone probably has a stack of. Anyway, it has a fairly decent update rate on the temperature, and I use that to turn on and off the thermostat heat in the other room. Since the other room's temperature is irrelevant, I can just shut off the thermostat when a setpoint is reached.

So its like this.
The thermostat is set to 76 (realistic high cut off) as part of alarm disarm and daily monitoring.

One event has is that zwave device tells thermostat to turn on if temperature is below room setpoint (70)

Another event turns off (set mode off) the thermostat after reaching or exceeding setpoint (70).

Thanks all!