Total beginner questions

Hello all,

I am completely new to home automation, I have no hardware yet, and I am still trying to find out what I need :slight_smile: It started with the idea to have smart thermostats, but some quick research mainly finds cloud-based solutions where you need accounts at the vendor etc pp.
This is what I want to completely avoid, and rather have a solution bound to my home network only, which seems to be possible with openHAB, as for my current state of knowledge.

To be honest, I am a bit overwhelmed by the plethora of possibilities, pieces of hardware, technologies and protocols. To get somewhat closer to a solution for me, here is roughly what I want to do:

  • have 2-4 heaters in my home use smart thermostats
  • those should be programmable, so e.g. they start heating my home before I come back from work
  • optional: should be controllable via iPhone app (but this is given already by openHAB I guess)
  • optional: should be controllable via siri
  • those thermostats shall not try to access internet, or should still function when beeing blocked by my pfsense firewall
  • at some point I might like to add supper for light switches, but not right now

I already have 2 raspberry pis, and I am familiar with linux and also a programmer, so setting things up in openHAB should not be a difficult task I suppose (from what i’ve seen in the wikis). The more difficult task will probably be the selection of suitable hardware.

Right now I like the idea of z-wave, for its claimed performance thru walls and so on, and the fact that it won’t access my LAN network/internet. I also found a thermostat which seems to be suitable:
https://www.amazon.de/Eurotronic-Z-Wave-Energiesparregler-intelligentes-Heizthermostat/dp/B075X257NC?psc=1&SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duc03-21&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B075X257NC

Is my assumption correct that I would need the following things done to make it work:

  • buy the above thermostat(s)
  • get a z-wave transceiver for rpi (USB or GPIO)
  • install openHAB on rpi
  • install z-wave bindings/driver on rpi
  • setup openHAB for the thermostats
  • connect rpi to thermostats

Are there any recommeded thermostats, connectors, other piece of hardware I should consider? I am completely new to this, so I have no idea what should be considered when buying. I live in germany, if this is of importance. I guess the above thermostats should be installable on my heaters.

Also, shouldn’t the thermostat have any external temperature sensor which I put some where in the room, instead of a built-in one (which might be less precise due to the proximity to the heater)? Or can this be done with separate sensors I add to openHAB?
Where should temperature sensors be put in a room? (probably depends on my home’s layout?)

Thanks for any comments :slight_smile: Hope it was not too confusing.

Google for HomeMatic, ELV
These devices are available in Europe. Relatively cheap. Not directly accessable from openhab, though there is a solution with raspi. As it seems, support in German is not a problem for you.

Homematic 105155 Funk-Heizkörperthermostat für Smart Home / Hausautomation

I always go :question: when I see requirements like:

" those thermostats shall not try to access internet, or should still function when beeing blocked by my pfsense firewall"

combined with

" optional: should be controllable via siri"

You are OK with sending your voice to the cloud to control things but nothing else?

I can’t answer all of your questions but I can address some of them.

  • Zwave is probably a good choice but not the only choice
  • The transceiver is called a controller. It does a whole lot more than just sending and receiving messages.
  • I would be surprised if the thermostats have external thermometers. But OH is designed such that it doesn’t matter where a sensor values comes from when you use them in your Rules so you can add extra thermometers and use those to drive your heaters.
  • Heating Boilerplate - A Universal Temperature Control Solution with Modes
1 Like

I always go :question: when I see requirements like:

I understand your reaction, still I think its quite a big difference if something is having access to both the internet and my LAN (and thus potentially to all my devices in the LAN, like NAS box, laptop, etc) vs. I send some command which was turned into text by the cloud to some (safe?) interpreter in my network (= raspberry pi with OH).
Anyway, I marked this as optional, as I rarely use siri, it would just be a nice to have I guess, I won’t really need it.

I would be surprised if the thermostats have external thermometers.

Those will have separate sensors:
https://control-your-home.de/fibaro-thermostat
But also they’re pretty expensive, although pretty to look at, not this standard nineties look. Although I am unsure of what the difference between the “thermostat” and the “radiator thermostat” is :face_with_raised_eyebrow:

Heating Boilerplate - A Universal Temperature Control Solution with Modes2

Thanks for this, looks like a really great and helpful thread.

@lukics

Google for HomeMatic, ELV

I found those already. Whats the benefit compared to those I mentioned?

You might want to do more stuff regarding home automation later and one good thing HomeMatic has is the direct chnannel connection between devices, e.g. Thermostat can talk directly with the valve controller. In my setup I used this as much as possible.

Which is why most people who are concerned about such things have a separate network for their IOT, even if they are not cloud based devices.

Which is why most people who are concerned about such things have a separate network for their IOT, even if they are not cloud based devices.

This is what I’m trying to achieve. I thought Z-wave would make this sure already. Tho I would have a separate WLAN, if necessary.

Zwave is separate in that it has zero interaction with your IP network or wifi beyond the fact that your controller will be in a computer that will be running on your lan (presumably). However, as extensive the coverage of devices zwave provides is, I don’t think anyone is able to have a pure zwave system. For example, if you want IP cameras, even the zwave ones transmit the video over wifi. There are no media zwave devices (e.g. speakers). And zwave is expensive. So you are almost certainly going to run into a situation where you have an iot device that needs wifi.

I think that would be okay, since I am renting a (rather small) appartment, so I might for now be okay with temperature control as well as some lights and/or switches. And I would still have the option of connecting additional technologies I think, even if some of the hardware uses z-wave.
I like the idea of z-wave as non-proprietary/generic connection which can be used by other hardware, without needing separate a proprietary base station of some kind (like homematic CCU1/2).

You can also have a look at the MAX! solution from Conrad.

Bit cheaper devices