Question About using Vera as a Thermostat

Other Devices & Integrations Climate Control & Temperature Sensors
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Question regarding the goal of making a thermostat. I am currently waiting for my 1st Vera device (the VeraPlus) :slight_smile: but have several goals planned.

One of my goals would be to increase the heat setting by a degree (F) or so during the day when the sky is overcast or vice-versa. I was thinking about goControl Model GC-TBZ48 running on 24VAC. Using Vera I could just bump the setting up or down to suit the conditions.

However reading several postings about using Vera to create a “Virtual Thermostat” I think there maybe another option. Can someone tell me what Z-Wave / WiFi / Zigbee hardware would be needed to implemented a “virtual thermostat” ?

In concept I might guess a temperature sensor for room temperature and a relay to control the heat might work on some systems. But I live in New England and have an oil hot water burner. I would be hesitant to allow full control to the Vera.

Any insight would be helpful?

Thanks
JohnRob

2

If your oil unit can run off a zwave thermostat, you can have scenes or PLEG scripts that adjust the thermostat target temp. Then it’s just like having a butler tweak the thermostat.

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JohnRob - I think most here would advise against setting up Vera as a “virtual thermostat”. When compared to any “real” thermostat" Vera as a “virtual thermostat” is far less reliable - and living in New England you need a heating system you can completely depend on to keep your home from freezing in the winter. Instead follow the recommendations posted in this forum for use of a WiFi or Z-Wave controllable thermostat - the thermostat retains direct control of the furnace, and Vera’s function is simply to adjust the temperature heating/cooling setpoint.

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hmb - Thanks for the comment. I agree completely! I not only would not give Vera full authority over my heating system but would limit any allowed modification to values to within a “safe” range (determined by thermostat settings, not Vera settings).

Still reading all the posts I am curious as to what folks are doing along this line.

JohnRob

5

I have the Lowe’s iris thermostat (ct101) on the first floor and a motion/temp Sensor in an upstairs bed room. Heat rises, and did so very well in my large centrally located stairwell, so previously my bed rooms were burning up or my living room was freezing.

The ct101 supports a pretty typical set of program modes, so it handles basic weekday-weekend/night-day stuff on its own.
In addition, at night if the temperature in the bedroom leaves the comfort zone, the vera tweaks the thermostat until the bedroom is comfortable again. I also have some rules to keep the bedrooms from getting too hot or the downstairs from getting too cold at any time.

I also have a sensor on my porch and have experimented with switching the house to fan mode over heat/cool on those cases the outside is more comfortable than inside but in my climate I run into humidity problems.

My favorite thermostat trick is using my pebble smartswitch to adjust the thermostat from my bed. Have a scene that increases the target temp and another that decreases it and install the vera scenes app. In about 3 button clicks you can modify the temps without leaving bed or fumbling for a phone. The changes will only last to the next program event.

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JohnRob: you asked if I could describe my heating system in another thread, but I’ll reply here since it seems more appropriate.

We live in Norway and the winter temperature here can get down to -25C and the summer temperature can climb well above +30C if we are lucky. Our house is also a bit special. Its a old horse stable built around 1880 which has been renovated into a house. Its not the most energy efficient house. I guess we traded that for a bit of charm. With this in mind its been very important for us to have a heating which does not completely shut down during winter.

Our heating is water based. We have a Mitsubishi Ecodan air to water system. It has heat pump outside and a storage module inside: Home - ECODAN

The Ecodan system is pretty much self contained. What it does is provide hot water. The inside unit has communication with the outside unit where it does measure the outside temperature and adjust the temperature on the water flowing in the pipes inside based on the outside temperature. There are some algorithms for this and these are adjusted to your house when its installed. The Ecodan is a kinda closed system and not connected or controlled by our z-wave network / Vera.

We have a certain temperature we want inside and we have adjusted our Ecodan to provide hot enough water to have this temperature inside. Then we use a set of thermostats and relays to keep the temperature at the level we want inside by turning heating units in each room on and off.

In the first floor everything is heated by floor heating (pipes in the floor). In the bedrooms, dining room and kitchen we have radiators. In the bathroom we have a water based towel rack which work as a radiator. We also have some big doors / windows in the first floor where each of them have a set of heat convectors.

All of these units (floor heating, radiators and convectors) have a actuator to control water going through the unit. An actuator is a electrical motor for opening and closing a valve. Our actuators are NC which stands for Normally Closed. That means that when they have no power the valve is closed and no water flows through. If one give it power the valve is open and water flows through. The actuators use 5-6 minutes to open and close so they regulate the water flow nicely.

We have actuators similar to those from Danfoss: Thermal actuators | Danfoss Global Product Store

To control the actuators I use the Secure SSR 303 relay:
http://www.vesternet.com/z-wave-horstmann-z-wave-controlled-boiler-receiver-hrt

This is actually just an on/off button. The only thing it does is turn the power to the actuators on and off.

Then I have the Secure SRT 321 thermostat which control the temperature in the rooms:
http://www.vesternet.com/z-wave-horstmann-wall-thermostat-with-lcd-display

This unit is paired with the appropriate SSR 303 relay(s). On the SRT one can adjust the temperature and it will control when the SSR 303 should turn the power on and off for the actuator(s).

My main reason for selecting these devices was that the thermostat has a manual control where one can adjust the temperature. Then I am not dependent on a controller to be able to adjust the temperature in a room. Then, the relay also have on / off buttons where I manually can turn heat on or off. This is important for me to have in case the thermostat fails to work at one point.

By having it like this I can manually control the temperature in each room and the devices talk to each other. There is no central unit controlling everything preventing me from having a single point of failure. I do not want my heating go down if a central unit fails. I am also able to manually turn heat on/off in each room if the thermostat breaks down. In other words; our heating control is very distributed.

My Vera controller does’nt really do much in our setup and I don’t want it to. The only thing I use the Vera to is to run a couple of scenes which will set the thermostats to a lower temperature level at night and a higher level at daytime plus lowering the overall temperature if I put the house in vacation mode.

I do also have a Secure SES 302 with a SES 002 pipe sensor:
http://www.vesternet.com/z-wave-secure-ses302-temperature-humidity-sensors
http://www.vesternet.com/z-wave-secure-pipe-tank-digital-temperature-sensor-1m-wire

This one is attached to the pipes which is the floor heating. Our floor heating has wooden parkett on top and the heat in the floor should not go above a certain temperature. The wooden floor will be damaged if it does. These devices then measure the temperature of the pipes and turns the water flow on/off to protect the parkett if it get too hot.

One thing I have not addressed yet (my next task) is to control the fans on the heat convector. A heat convector is just a radiator with a fan blowing air through the radiator. At the moment I am just controlling the radiator as described above. I am not 100% sure how to control the fans but I have been advised not to have them run constantly when the heating is on. They should run in bursts / small periods of time.
I am thinking of using a Secure SIR 321 to control the fans:
http://www.vesternet.com/z-wave-secure-wall-switch

The SIR 321 will give me a manual unit to run the fans for a certain amount of time. Which is what I want.

I am not sure if this helps you but this is at least our setup and it works pretty well.

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Hi trygve,

Thanks for the comprehensive reply. I think I understand the farmhouse charm. My grandmother was from Mandal and our family still lives in the home (upgraded of course) her great grandmother was born in.

Regarding your text. It is very interesting, and if i understand it properly, the actual heating unit is controlled by a local thermostat. This is different from what I was trying to understand. In many posts folks are talking about a “virtual thermostat” there is even an app named “Virtual thermostat”. I imagine such a system would be something like:

  Temperature sensor ---> Vera ---> heating (whatever the type).

My first thought is if the Vera hung up, the heat could remain either completely off or full on for an extended period of time. I personally would not feel comfortable with such a system. And from what I read or your system, neither do you.

Essentially my question is: Is someone actuality using the Vera as a thermostat and if so what is there hardware setup?

Regards

JohnRob

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Search for “virtual thermostat” to find people using them. It tends to be folks with electric room heaters with non-existent or rudimentary thermostats. Someone probably does use it with a system functionally similar to yours.

I would say keep the load on the vera to a minimum to avoid issues. Honestly, a vera is about the cost of a high end programmable thermostat so its worth considering two Vera’s and dedicate one to HVAC. I expect veraplus to cause a price drop on vera lite.