In general, retrofitting with KNX in existing buildings is quite difficult. The green KNX bus cable is a central element of KNX systems and connects the actuators and sensors in the smart home. If the cabling has not yet been installed, retrofitting often requires a lot of effort (eg wall grooving). An alternative wireless solution, e.g. With KNX RF, it is often an easier option.
It is important to note that the structure differs from conventional wiring. In a traditional electrical installation, the electrical wiring from the distribution box leads to the luminaire via a flush-mounted switch. Turning the switch closes or interrupts the electrical circuit and the lamp turns on or off. The KNX installation is set up differently: The bus cables lead from the control cabinet to various devices. There is no connection between the switch and the lamp. The cabling system is then supplemented with suitable actuators, sensors and displays. What exactly the switch or button should then control is determined during the parameterization of the components. Once everything is installed and properly parameterized, the devices can communicate with each other. KNX installation is therefore much more flexible than conventional electrical installation.
For new construction or complex renovations, the bus cable can be placed in the wall next to conventional power lines to interconnect the various KNX-supported components. If many empty pipes were laid during the construction phase, later retrofitting with KNX cables is easier. In this case, KNX cables can then be installed without having to open the entire walls. This often happens, for example, in modern office buildings.
Thanks to cabling, the KNX system is significantly more stable than wireless solutions. In addition, it is a standard established for years. Thanks to worldwide distribution, there are already more than 8,000 certified products that are compatible with each other. The KNX system can be flexibly reprogrammed if the requirements change and can be connected to other protocols. In this way, radio solutions such as KNX RF, DALI or EnOcean can also be integrated into the system. The KNX standard is therefore also the one to which there are the most interfaces in building automation. Due to its wide use, other smart device manufacturers are also motivated to implement the connection of their products to the KNX installation.