Home automation planning and costs

I would, for example, as long as it does not directly glare, leave the blinds up and instead air condition. We will probably install a brine ground heat exchanger in the controlled residential ventilation system and an active underfloor cooling system. I don’t know if that will be sufficient. But if it should be sufficient, then I’d rather pay a few cents more in electricity costs and have it nice and bright instead of half-darkened. Since I work with venetian blinds daily and set them just so that they don’t glare, I also know that venetian blinds darken quite a bit. At least for my perception of brightness regarding natural light. My colleague often turns on artificial light then. Open light through the window is something completely different in terms of room illumination than a venetian blind tilted open. We have a huge window front, but with the venetian blind, it’s still dark. If it doesn’t glare at the moment, the blind goes up and the AC comes on. But regarding automation, you would really need a KNX direction sensor on every person to detect glare. I think that doesn’t exist, right?

Of course, the exception is when you’re not home. Then I would just leave all the blinds down by default, the darkness doesn’t bother anyone.

What bad thing happens if you forget the light? 12h a how many watts does an LED have?

Nothing, yet there are people who want all the lights off after they leave the house...and then there are others who deliberately want to leave the light on...people are just different...

And who has a moisture detector in the cellar that is linked to the main shut-off valve? And why KNX? That is a simple if-then automation. For that I can rely on something proprietary.

Safety-relevant installations have something like that on board...you could also use something proprietary for that...but then you take a step back again and who wants that?

The comparison with the light sensor is not bad. I always automatically turn on the light 5 seconds after ignition. Even in August at noon sun.

Maybe you do that...but I don’t, and I don’t want to either...the light should only come on when it is needed.

I think what’s important in a car are the model, features like leather seats or the performance. Better an E-Class without a light sensor than a Golf with a light sensor.

Then replace the model name "Golf" in my example with "E-Class." That too exists in base or other equipment variants.

The other problem is, you don’t have to reprogram the light and rain sensor in the car every few weeks. There is a logic that is universal. In the context of individual, daily changing life habits in a single-family home it looks very different.

You are, but very much on the wrong track...

Otherwise the car comparison is great, you have to buy an expensive package for rain and light sensor, which includes lots of stuff you never need and never use, the time saved is minimal and sometimes the (light) rain sensor doesn’t work the way you want, and you have to intervene manually and first have to figure out how because you only do it occasionally, not regularly.

With KNX no one is forced to buy expensive packages...there is always a way to assemble a desired system. With exactly the functions you want. Among other reasons because you can mix manufacturers and assemble the appropriate functions for yourself.

Applied to cars it would be like this:

Chassis from Audi + body from Mercedes + electronics from Toyota + interior from Porsche + engine from BMW

You just pick the right devices from the 350 KNX manufacturers and connect them all with one cable...and they all work together flawlessly immediately.

Otherwise that’s not true, you still have to do quite a bit of wiring even just for lighting, and reading here you should then also lay a lot of "empty bus" in the rooms because otherwise it’s hard to retrofit.

The wiring for lighting is simpler than conventional. With KNX in the simplest case you only have one 3x1.5 NYM cable from the panel to the point of use...the bus is there everywhere anyway...conventional needs a junction box in the room and a switch.

The "empty bus" I wrote about several times here is not necessarily needed...you can prepare it but you don’t have to...

And, even if you don’t realize it, you pay for a lot of functionality that you don’t use yourself. I think the system, the bus and the devices often have a capacity that is rarely fully utilized in a single-family home. So I would contradict the thesis "you only buy what you want." But otherwise it’s often the case that it is not possible to get a completely individual product for a mass market price.

No, as I wrote earlier you don’t have to pay extra if you don’t want to...you can buy exactly the module with the required functionality...that’s the point...you’re not tied to one manufacturer and have to pay for extras...and if you want more functions it’s enough to replace the device with a newer one with more functions...often in the control cabinet or the flush-mounted box so that no walls need to be opened...also with KNX.

There is no bus technology installed in our office.

And what is that supposed to tell us? Just one office among millions. Maybe your venetian blind would be more bearable for you with some intelligence...

The range of variables is so broad, something like that could not be automated adequately.

And yet it works very well, with bus systems...just ask in the KNX user forum...there are quite a few with automated venetian blinds.

Tracking device on every person to detect glare. That doesn’t exist, I guess?

Yes, they do exist.

But as Uwe82 already said...you have to experience it...all talk is useless...

Mycraft, you did not understand my argument about the costs for unused functions. I do not believe that even you (and most people far less) use all the functions of the purchased devices, etc., and you pay for this overhead of the entire KNX system (as with other automation systems as well). Aside from that, (almost) everyone here agrees that it is a comfort (and mostly gimmick) system that has an advantage over other systems. The question of whether one even uses such a thing is certainly a matter of taste, so this discussion simply will not lead to a result.

from on the go

Mycraft, secret shareholder in one of the leading manufacturers of KNX components, but on the other hand also obligated as a moderator to neutrality. Please introduce us to three typical... typical (!) scenarios where KNX makes life better.

I still don't buy the thing with the soil moisture sensor and the KNX main shut-off valve as something realistic that more than 5 users in Germany have actually installed.

But the comparison should go like this... Use cases...
KNX user: I open my patio door. The roller shutter automatically goes up. (And a brief technical explanation of which sensors, switches, actuators, etc. make this work)
Standard user: I tap the roller shutter up and open the balcony door

And now we look for use cases where KNX saves more than just 0.6 seconds. These surely exist, but make it tangible with concrete examples like a) KNX does it this way and b) a sensible (!) conventional control still requires these additional switch presses...

By the way, my main argument for the controlled residential ventilation (about 10,000 EUR) is still that it saves me 20-60 minutes of manual ventilation work per day. What do I get in KNX for 10,000 EUR and is my payback then also 20-60 minutes per day?

But I understood you exactly.

Example switching actuators with me:

I have dumb actuators that can only switch on/off and have staircase lighting function; these are completely sufficient for simple switching tasks.

I have actuators that additionally master logic functions.

And I have actuators that also have a bunch of functions like, for example, current measurement... meaning during operation the current flow is continuously measured and depending on the level, various scenarios can be triggered.

The actuators had different prices depending on their function... You see, you don’t have to pay for functions you don’t use...

Of course, you have to pay the development and certification costs and also the margin... but you have to do that even without a bus system.

Mycraft, secret shareholder in one of the leading manufacturers of KNX components, but on the other hand also obliged as a moderator to neutrality. Why don't you present us with three typical... typical (!) scenarios where KNX makes life better.

No, I am simply convinced by the system...