Automation - Solar + Heat Pump + Ventilation System

Hi everyone!

I am just starting my journey with Home Assistant and have some ideas that might or might not be feasible. Any Input is much appreciated!

What is my Plan?
Well, we have ordered a Heat Pump for our house (Vaillant Arotherm Plus 55 with SensoComfort 720 Controller) and also a Solar array (7.7KWp with a Huawei Sun2000 Inverter and Huawei Power Sensor).
These components should arrive within the next 6 Months or so. Supply Shortages and so on…we all know the story…

What we already have is an older Ventilation System (Vaillaint Recovair Var/3 275) that doesn’t have any kind of automatic adjustment and a small test-bed solar Setup with a 600W Growatt MIC 600 Inverter.
Our current (and future) heating is controlled by Homematic IP room thermostats that regulate a floor heating system).
I also have a Powerfox energy metering thingy that allows me to read and document my current energy Input/Output.

My aim is to use Home Assistant to knit the various systems together in a way that makes them as efficient as possible. Theoretically the new Heat Pump Controller could mesh with the Solar system, but AFAIK that only works with Inverters that support EEBUS which Huawei doesn’t.

I installed HomeAssistant on a RPI 4 with 8GB of Ram this afternoon and have added some Devices and Sensors. As a little Test I have made the following Automation:

When the Powerfox dongle measures excess energy then it turns one of my Hue Lamps in the kitchen on and makes it show a steady blue light. As soon as the energy consumption rises above what the 600W mini solar array can provide the light turns off.
This is’t very useful but allows me to learn a little about HA and how to set things up.

For now the only thing I can work on (since Solar+Heat Pump are still a few months out) is the Ventilation system.
My idea would be to make it react to one or more Sensors and turn airflow up and down accordingly. I know that it has an analogue Input that you can connect a “dimmer switch” to and regulate the airflow smoothly by applying a 0-10V signal. Initially I could use the “Humidity” reading from my HomematicIP Thermostats as triggers for this Automation.
That is as far as my knowledge goes though…and this is where I would like to ask for help:

How could I manage the 0-10V Input Signal to control the airflow? Any ideas?


Additionally…and ideas on how to best link a Vaillant SensoComfort 720 and a Huawei Inverter…would be very much appreciated!

Hy CommanderROR

I am trying to create exactly this scenario in the automation. But I am not succeeding.
Can you perhaps provide me with the script here?


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I don’t have any solution yet, mostly because I don’t have the Solar system or heatpump yet, but I have made some progress in the ventilation system.

It is still very much WIP but it works OK for bow even if it isn’t very sophisticated or elegant. I have posted my findings here:

Please be aware that the code posted there is outdated, I didn’t have time to upload my improved code yet, but will do so later today. The Heat Pump + Solar integration might be simpler than the ventilation system since both Vaillant and Huawei offer web interface/app controls and those should allow control through Home Assistant. Without having the appliances I can’t say how well this would work though.
My idea is to create an automation that checks for excess electricity coming from the Huawei Power meter (or my PowerFox energy sensor) and then create a “reaction” on the Vaillant side. This could work better or worse than simply using the SG Ready relais on the heat pump and switching it with a Shelly…

Anyone have a solution for pulling data out of the AroTherm into HA ? I want to read the likes of Flow and Return Temperatures, the Input Load kW and the Heat Output, and any other info available

The only way I know of to get significant data is to buy an ebusd adapter and then find the correct .csv for your system… it’s a rather involved process, but have it set up you get plenty of data.
If you only want the basics you can go with the “myVaillant” integration but that won’t even give you the flow rate in l/h or the return temperature.

Thanks for that. That eBusD looks like the perfect job indeed, especially when MyVaillant doesn’t give you everything, and of course eBusD is a fraction of the cost, and more to the point, is not reliant on anything Cloud based

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