#Choosing hardware for a newly built house - considerations/recommendations

1 messages · Page 1 of 1 (latest)

pliant vessel
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I'm starting the design of my new house and planning a HA setup for it. I'm mostly settled on running HA itself (virtualized either on Proxmox directly or via Kubevirt), but I'm not sure how to approach devices/connectivity concerns, especially lights and temperature/door sensors. I have a test setup in my current apartment using a mix of wifi and BThome, but reliability isn't great. At the same time there's a lot of wired options on a lot of protocols, and while HA can technically integrate with all of them, I'm wondering if others have had some concrete experience with some systems, what to avoid etc.

For example, I'm planning to run multiple ethernet cables to every room. At the same time, I guess that running lights to boxes is a better idea than running constant power to them. So there would need to be a mix of boxes that have a set of electricals and one ethernet connection, and then either I add a switch inside or use a singular control unit driving relays or dimmers via some more primitive bus interfaces.

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I know that there are at least two failure conditions to consider

  • failure of the internet connection
  • failure of the HA connection

The latter could be broken into

  • failure of the local network
  • failure of the HA instance

As well as, quite obvious, the failure of the electricity in the entire building. This one I plan to deal with via a hybrid PV inverter that can run off of the house power bank unit.

As far as the HA instance, I'll likely run it monitored and virtualized with probes that can fail it over to another hw machine. I plan to mostly use real servers, with UPSes and dual power supplies, as well as a separate storage server, and treating the entire thing like a real datacenter. I believe this is a much more robust solution than a small Pi or similar.

For the network, I'm not planning on individual UPSes, instead to rely on load shedding when the backup power reaches critically low battery levels. This should ensure controlled shutdown of less critical but more power hungry units.

The internet connection obviously isn't necessary for anything.

All that being said, HA being the brains of the operation still introduces more failure points into the system, so I'm really eager to hear your opinions about it.

woeful veldt
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Smart switches > smart bulbs

Smart switches will work as people expect, and will work if/when HA is down. People don't have to learn new behaviours.

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Beyond that, wired is clearly better than wireless, but also costs (often quite a lot) more

pliant vessel
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i.e. I'm planning the control scheme first, and then will design the system to match, not the other way around

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AFAICT anything that has its own mcu inside can work when HA is down, as long as it has the minimum to work; e.g. a shelly brick in a switch can be hardwired to that switch and expose both the light entity and the switch entity

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at the same time if HA drops, there's a hardwired link between the two - that's how I have it it set up now; I'm just not sure how it will scale to a bigger house

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I'll have multiple lights controlled by one switch and one light controlled by multiple switches

marble blaze
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have you taken KNX into consideration?

pliant vessel
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and in that sense it's forming a unifying layer on top of all the devices that support it

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Other than communications, I'm not exactly sure what else it brings to the table; e.g. Shelly's KNX-over-IP-over-WiFi devices are still as reliable as WiFi itself, and their disconnected operation relies on the hardwired switches

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Frankly I'm not sure if a total network failure is something that has to be considered when it comes to the house operating. I suppose it would be pretty bad if all the lights, heating etc. stopped working if a cable is unplugged, but then again I'm not sure what would be a proper way of handling such a scenario

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each device would need to be programmed not just to react to networked input, but also to local input, and then rely on its own internal state

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what scares me in that is that those states can potentially conflict with what resides in HA... I already had issues with my wifi desk lamp turning itself off because it lost connectivity and its internal logic told it to turn itself off despite the server wanting it on

marble blaze
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KNX is most of the times used in the bus wired configuration(2 wires). Each button, relay, actuator, switch,...... is a controller on its own each device has an programmable id, and the devices broadcast data that other devices listen to and act if needed

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the integration to home assistant works flawless at my home, its always in sync

vital yew
pliant vessel
pliant vessel
vital yew
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Electricity will definitely be different. Most of the low voltage stuff should still apply though.

marble blaze
pliant vessel
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i need to read more about KNX, from what I know it's used in industrial installations and is indeed pretty reliable

pliant vessel
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Well, I did read some and it's pretty scary 😄
As far as I understand it, it's all standardized but at the same time quite complex. There's a lot of possibilities but getting the config to the devices requires a lot of minute changes. The wiring also gets more complicated as the devices use LV power in addition to the bus itself.

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I'm pretty sure that if done well, such an installation can be very robust and do virtually all that's needed, but I am afraid that for me as a hobbyist it would take too much time to make it work reliably. In a sense, I need to strike a balance that produces the most reliability for the effort. Cloud-based is very easy to set up but has a low reliability ceiling. KNX has a high ceiling but getting there takes a lot of time.

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One observation I've made yesterday is that Shelly Pro devices, especially the 4PM, still come with switch inputs. While primitive, those allow control over essential switchable lights in the event of network failure via hardwired switches

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since it's all done within one device, it's pretty reliable (which is confirmed by my use of wireless shelly bricks) and gives me that peace-of-mind that even in the event of total network failure, some additional emergency switches could still turn the lights on

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it's reasonably cost-effective, they work well with HA, they have builtin PM as a bonus and can also be controlled from the DIN rail if everything else fails

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oh, and there's wifi in there too, which could help mitigate network outages if that's possible

runic spire
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You essentially never have to run wires from switches to loads - which is very nice when doing that yourself.
All the loads (eg. 230V) run straight to the electric cabinet.
The switches, presence detectors etc. can be daisy-chained throughout the house by bus cables.

pliant vessel
pliant vessel
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in fact i guess i could reuse ethernet cables for the bus, right?

runic spire
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Well, in theory you could, but in practice you shouldn't. There are dedicated, certified KNX cables available that fit perfectly in the little device sockets. Additionally they are tested for safely running them next to 230V cables and are way cheaper and more flexible than most ethernet cables.

pliant vessel
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the only downside is I'd need to lay out another "layer" of cabling predicting where the bus would end up being needed

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oof, and they're actually more expensive than CAT6

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but yeah, linking in a bus would mean needing much less of it and wiring being overall simpler

pliant vessel
runic spire
runic spire
pliant vessel
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right, looking at the same producer (here locally), they sell indoor FTP cat6 cheaper than KNX-specific cabling

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of course that's still a far cry from something like Loxone's Tree cable 😄

pliant vessel
# runic spire No.

that's so weird... can't say I'd be happy having to rely on something like that

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but as i understand KNX isn't an open standard at all, right

runic spire
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It's an open standard. The configuration application isn't open.