Beginner looking for Basement Fan Control Hardware and Dew-Point Calculcation

Setup, Configuration and Use Scripts & Rules
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Hey there,

i am new to OpenHAB but as i am a media technician with some medicore Coding-Skills, i think i’ll find my way through open hub.

Up to now i’ve got some “dumb” and some semi-smart systems around my house (Like automatic cicstern-refill, some AVM/Fritzbox 230V-Plugs).

The problem i am getting in now is i wanna build a Ventilating System for my 60’s humid concrete basement in the old house i bought. There are some systems like maico on the market, but they seem very expensive for that little amount of logic they use. As there are no inhabited rooms in the basement, i don’t need thinks like warmth-recoupling and i may use some pretty simple marley pipe fans (and mybe Filters in the tunnels).

So what do i need? First of all some indoor and one or two outdoor humidy/temperature sensors.
Then some Relais stuff i can talkt to for getting the fans started.

And then i need to get the rules when which fan has to move or not. So i think this might be the right place to use scripts?

I have to calculcate the dew-points from inside sensors (for that single room) and outdoor first, then see if it is useful to start ventilating, then check if it is above a safe minimum temperature. If temp too low or dew point difference not high enough but basement humid is above 70, go and switch on that dryers.

So how to get all of this together? Is that kind of stuff possible? (i think/hope so!)
Which Hardware to choose?
WiFi is available all over the area through mesh. So get some IP Stuff? Or better get on z-Wave and a gateway? Which Sensors are precise and durable? How to Switch the fans? As the whole Basement is surface-mounted, i can put a DIN Relais with IP in the electrics cabinet, i can give them single wifi relais and so on. Even Wired Ethernet is near the electrics cabinet.

So where to start? Up to now it’s “just” that fans and sensors, but i want to build open sprinkler next year in the garden and maybe get some sensor values, statuses, waterflow etc.

Then maybe Stuff like talking to my AVM-Actors, integrating some button-Remotes for granny and visualisation panels for us. Maybe thrash-calendar, maybe “The Washer has finished” messages and all that stuff.

The rPi is ordered. What now?

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I have such a dew point based ventilation in my home, and washing machine notification, too.
It’s based on ZWave because that was available by the time I’ve built it. But either will work so you have to make a major decision first if you will want to use ZWave (or maybe ZigBee ?) in the long run or stay with WiFi forever. Take your time, don’t decide because of your first application.
Think of all your future applications, think radio range and think batteries: where will you be having mains power available ?
WiFi is power hungry, you cannot run sensors on battery. With ZWave and ZigBee, you can.

Sensor selection and precision doesn’t really matter (sensor placement does, though). You can all override/compensate it in software if needed.
Using radio is absolutely fine here, no need for any cabling whatsoever or DIN rails only electricians would favor those (because they always want to have wires).
Just remember not to place radio stuff in cabinets (Faraday …) or make at least sure it’s a plastic one.

PS: (warning, advertising) I’m also providing professional consulting services and I’m actually selling a ‘smarthome as a service’, i.e. the customer contributes the server and devices himself and I’m providing the software to control them, including the source of course.
I’m right now evaluating possible packaging variants but I think a ventilation (-only) module probably isn’t worth an own ‘product’ so the code will more likely become a part of the base package (together with washer notifications, presence detection and a couple other useful basic functions). Send me a PM if you’re interested.

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yeah, as i am half an electrician myself and the basement needs new cables in most places anyway, i wouldn’t mind if i pull 3 wire cables to the fans and switch em at the end via some kind of rf module or if i use 4 wire cables so i have permanent power alover the place and have a line that only is the “fan rail”.
I thought if i use sth like open hub, it doesn’t really mind what device has which physical route. So i could use like MQTT or Plain html/Json (hope there are modules for plain protocols?) to switch some relais wired but use things like z wave/zigbee at the same time. At the latest point in my garden project i think i have to use one of those for the sensors.

For the radio in the cab: I’d prefer external antennas, as i’ve got rock solid german metal cabinets here :wink:

For your system/templates: You’re selling the service or the code?

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Correct, openHAB doesn’t care about the physical layer. You can choose whatever devices with whatever protocol is cheapest or easiest to implement, depending on the location. So you can have ZWave in addition to Wi-Fi or even Ethernet and ZigBee, or even all of them in parallel.
The more ZWave or ZigBee devices you have the more stable your mesh network will be so don’t use more different technologies than you really need to.
There’s device versions meant to be put into walls with ~5 cm antennas but few to none with external antennas.

It’s the code in the first place, but you can also get the implementation service or consulting.
Please contact me with a personal forum message if you’re interested.