Help needed on KNX/HA system design

I am renovating my house using KNX as home control platform that I plan to integrate into HA for controls and automations. The topology is the following:

  • 4 Floor house, each floor having:
    • individual KNX power supply (1),
    • DALI DT8 gateway (1 with ~35-40 DALI dimmable and tunable lights),
    • blind and switch actuators (8),
    • presence sensors (15), and
    • touch pads (7)
    • HVAC indoor units (5)

The KNX of each floor will be connected to each other using IP router.

I will be grateful if you could let me know how many KNX devices (lights, sensors, AC units) can be integrated into home assistant through a single IP router. I read somewhere that I can only integrate 150 control points through a single IP router though in that case line couplers were used to connect different floors.

Secondly, is going with HA the best choice for the logic control of the whole system? Do I have any advantage using other options like ELAN SC100 controller, or Logic Machine 5 lite. I apologize if I am posting this query in a wrong place.

Well, asking this in a Home Assistant Forum will probably yield opinionated answers.
But with Knx you are not bound to use only one system - you may use multiple in parallel if you prefer.
In my installation I use a dedicated heating logic controller from ABB, a Gira Server for some logics and HA for connecting non-Knx stuff like HomeKit and for Visualization. Works great.

Why do you want to connect each floor via a router instead of TP (line couplers)?

Thanks a lot for your quick reply.

I read somewhere that the communication on the BUS is more efficient with IP routers instead of line couplers. What topology do you suggest given that I want all the mentioned things to communicate with home assistant.

What topology do you suggest for the configuration I mentioned, if I want to control and integrate everything with home assistant.

Do you think HA is a good enough controller or I there is some other platform that has advantage over it. I am asking your opinion.

There’s the question of how much bandwidth you need for ~150 devices. TP doesn’t need any LAN switches etc. so fewer moving parts and way cheaper.

But HA can speak Knx routing natively (but not Secure Routing) so you should be fine. It’s not that well tested as Tunneling as hardly anyone uses it.
You can always choose to do Tunneling into one line (even Secure) if you like.
Routing may involve some more filter table grooming (or deactivating) but that should be fine.

I’m a developer of the HA Knx Integration so my opinion here may be really biased. I also have not used other open source projects like NodeRed or OpenHAB yet.
For me it works just fine and is stable. HA has a tight update cadence - and I personally like that. Missing some major releases and updating without having a glance at the release notes (at least breaking changes) is not the best idea.
(That’s the reason my heating is controlled by a commercial specified device - I don’t want to deal with any changes there).

Id not worry about the size of your installation though. HA can handle that just easily.