KNX system in the construction phase / later adaptation possible?
KNX in the construction phase is an important topic. Many apartment and house owners know it: The money just "flows", the plumber, tiler, builder, etc. cost a lot of money and you want to save where ever possible. Of course, the question of what can be saved in electrical engineering is also considered.
Saving is possible, it is important to consider that later extensions are easily possible when the household budget has recovered.
So what can be done with a new building to set a good basis for retrofitting or adapting at a reasonable price later on?
Good planning of most importance in order to prevent chiselling the walls
The most important decision is that of the power distributor. Is everything controlled by a single distributor at a central point, or do you opt for floor distribution in addition to main distribution? This would mean placing a large distribution cabinet in the basement or in a niche and using further small distributors on the individual floors, which would then be connected to the main distributor.
How large should such a distributor be? In general, one can say that it would be better to get a slightly larger one than too small, so that there is still room for expansion. Later conversions to a larger distributor can be very cost-intensive.
Furthermore, you should also think of your own cable duct, so that you can distribute all cables in the house and subsequent expansion is possible. Nothing is more annoying than not having enough space for another cable. Of course you also have to take care to isolate power cables from network cables or satellite cables, otherwise interference can occur.
Cabling – essential part of planning process
Even if you are allowed to lay KNX bus cables next to power cables, you should consider laying them separately in order to avoid unlikely influences. You can also save money here – but be careful not to save money in the wrong place. Good planning is the most important thing.
"WLAN access points are getting better and faster, but communication problems or speed losses can still occur. It is still true that a wire connection is faster and more stable than a wireless one."
The use of conduits is a big advantage, as they offer the possibility to pull more than one cable in narrow places.
As a precaution, wider conduits can be installed, so that you have the possibility to pull in more cables during later adaptations.
Even if you do not have the necessary budget for the installation of a KNX controller at the beginning of the house construction, the green KNX cable can already be pulled in with the basic configuration. This saves you the trouble of having to pull in the cable at a later date. Even if you are still undecided which KNX controls (e.g. automatic roller shutters, alarm system etc.) you need, the necessary empty pipes and empty sockets can be pre-installed in the most important places (e.g. windows, doors etc.).
Also for the lighting, the KNX wiring to the distributor can be pre-installed at each light outlet and the sockets. The "central off" function is therefore already well prepared.
The costs for the pre-installation is low compared to the time saved later.
With a good preliminary concept / basic concept, you can be sure that you have prepared all the essential steps for the smart home.
Network cabling and fuses
There are many options for selecting fuses: Fuses with tripping delays, fuses with fire protection function or also fuses with combined miniature circuit breakers (with integrated fault circuit breaker).
Legal regulations specify which fuses may be used and how. However, there is still room for manoeuvre, so you can assign sockets and light outlets to your own circuits. This gives you the security of knowing that the lighting will continue to function even if a device becomes defective. Nothing is more annoying than when the entire apartment is in the dark due to one defective device.
I therefore recommend my customers to secure all rooms separately.
When planning a house, it is also important to think about the network cabling. WLAN access points are getting better and faster, but communication problems or speed losses can still occur. It is still true that a wire connection is faster and more stable than a wireless one.
"Even if you are allowed to lay KNX bus cables next to power cables, you should consider laying them separately in order to avoid unlikely influences."
A larger network cabinet, even if it is not used to its full extent at the beginning, is often better because it can be expanded later (e.g. server for visualisations, network storage, telephone system, Internet modem, etc.).
It also makes sense to consider whether the network cabling should be connected to the distribution cabinet so that a WLAN access point, for example, can be installed via a central location on each floor.
When planning, one should also consider how many network sockets are required in the individual rooms and where these are to be installed (e.g. with the HiFi cabinet, study, television in the children's / guest rooms, etc.).
In view of the growing amount of data, the network cabling should be at least Cat6, even better would be Cat7.
Would you also like to provide the garden house with a network connection? Then you can consider using optical fibre – this provides galvanic isolation and prevents any external voltages from escaping.