Domoticz

Hi Guys,

I am new to the world of domoticz. I am planning to build a heating controll system with danfoss LC13 valves on the radiators, so every room can be monitored separately. Now I have a few questions concerning the design
1/ Is a thermostat really needed? Because, if I have a thermostat, I cannot adapt the temperature in the bathroom or bedroom, when the living room is on the right temperature. I would prefer to use heat sensors. Are they reliable and responsive?
2/ I am using an ebus kettle, I wanted to connect the USB-EBUS adapter to the raspberry and send from the raspberry a signal to the boiler if somewhere heating is needed. If I need a thermostat, what would you recommend to use as thermostat, that is compatible with ebus?
3/ Is there a way to override the measured temperature by the thermostat and switch on/off when for example the bathroom needs heating
What do you guys think?
Thank you for your help

Hi Jorrit,

I'm in the middle of the same progress. I have the popp TRVs witch are the same as the lc13 only they report back the temperature. I want the use the script of @bobkersten take a look at this topic viewtopic.php?t=9915 no thermostat is Neede, just use a relay or your usb option. You can add temp sensors for every room. Im a little stuck now but i think i can get it going with the help of @bobkersten

I can personally give you my opinion about point 1

I'm in the process of replacing my valves with several LC-13 (I'm just waiting for the winter season to end to empty the pipes and replace the hardware) and I will use an external thermostat placed in the middle of the room.

LC-13 provides a SetPoint device (and a clock which I'm not really sure what's that for... but I think is almost useless with domoticz) but it does not give the temperature.

My intention would be to set a temp... but keep monitoring with an external device and aventually act + or - 2 degrees to reach the desired...

example:
- Temp wanted: 22
- Temp Setted: 22
- Temp in the woom: 20
ACTION --> Rise 1° the SetPoint

More...
- Temp wanted: 22
- Temp Setted: 22
- Temp in the woom: 24
ACTION --> Lower to 20° the SetPoint

My heating system is centralized and I monitor also the water temperature... so I would use that to eventually evaluate and preview future action
Example:
- Temp wanted: 22
- Temp Setted: 22
- Temp Pipe: rising from 49° to 54°
- Temp in the woom: 20
ACTION --> Do nothing (water in pipe will do the rest)
Even if in this case I would expect the LC-13 will close the valve a bit... but I want to be sure about....

ciao
M

Keep in mind that these are battery powered devices! Of you have the oportunity to use main powered valves (like directly on the manifold) don't hesitate to do that. I even plan to replace my manifold by a version that supports electric valves on it, like used in a floor heating system.
The Danfoss doesn't report it's battery status reliable resulting in open/closed valves without knowing it, that is until you feel somethings wrong.

Egregius wrote:Keep in mind that these are battery powered devices! Of you have the oportunity to use main powered valves (like directly on the manifold) don't hesitate to do that. I even plan to replace my manifold by a version that supports electric valves on it, like used in a floor heating system.
The Danfoss doesn't report it's battery status reliable resulting in open/closed valves without knowing it, that is until you feel somethings wrong.

That i know. But what about the thermostat. Is that more or less efficiënt than the fibaro motion sensor temp?

A thermostat is nothing more than something that switches a heating on when it's to cold.
If you can control your heating with the USB thing do it, why not?
You only need a thermometer then in each room you'd like to control.
I don't use the thermometers of my fibaro motion sensors, never used it, so can't say if they're good.
I can tell that the thermometer in the Fibaro Smoke detector is extremely fast and accurate.

Do you have any best information about the heating control then share here please.

I have some general experiences on Thermostates and heating (for what it is worth).

I have been using (classical) radiator-thermostates for 20 years. You don't need (want!) a room-thermostate, because if that is off, the radiator-thermostates in other rooms are useless. You DO need a central thermostate that measures the outside temperature and regulates the water temperature accordingly. If it is cold outside, the water should be warmer/hotter. In general, there should always be warm/hot water available.

You will have to use radiator-thermostates on all radiators but one. One radiator (best on the coldest place in the house) should always be open to allow water to circulate (we have it in the hallway). You can mix classical radiator-thermostates and electronical radiator-thermostates in the house.

The Setpoint-temperature of an electronical radiator-thermostate is just an indication. It represents the temperature in the direct environment of the thermostate and not the general temperature in the room. The Setpoint and the room temperature can be many degrees apart!

Example-1: One radiator is behind the cauch/sofa. It has limited air-flow. For a room temperature of 20 degrees, the Setpoint has to be 26-28 degrees.

Example-2: A radiator in front of the window experiences a cold airflow. It needs a Setpoint of 18 degrees for a room-temperature of 20 degrees.

I have set my electronical Thermostates (LC13) with a wakeup interval of five minutes to react quickly on changes from my script. I would like it even quicker, but for now battery-life is the bottleneck.