Mycraft
2019-12-18 13:33:36
- #1
KNX Installation (or another BUS installation) compared to conventional electrical installation
Requirement: You want a blinds control.
Conventional blinds control
In a conventional blinds control, the installer will probably mount an anemometer or perhaps even a weather station outside the house. This not exactly inexpensive device will have the task of triggering a wind alarm, upon which the blinds/shutters are retracted, or lowering the blinds when a certain outdoor brightness level is undershot. However, all measurements provided by the outdoor sensor are only known within the blinds control system; it is a closed system, an island. For example, if you want to use the measured brightness additionally for automatically turning on the facade lighting, this is not possible. In conventional electrical installation, the installer would simply install a second brightness sensor for the outdoor lighting – possibly right next to the already existing one.
What happens if you later want to automate the awning so that it shades the terrace from a certain brightness (or temperature)? Right: Either it is not possible at all, or the responsible technician will install a third sensor on the outside wall besides the other two. Apart from the fact that you pay three times for the same sensor value, such constructions are neither aesthetically pleasing nor maintenance-friendly nor flexible.
Blinds control as BUS installation
How would this scenario now be implemented in intelligent building control? Only a single device (weather station) is mounted on the building. The weather station provides measurement values (brightness, temperature, wind, rain, etc.) in the form of telegrams over a bus system. Every participant connected to this bus can receive and process all measurement values arbitrarily. In this case, it would be a blinds actuator for the blinds control, a switching actuator for the outdoor lighting, and a roller shutter actuator for the awning. And if you want to control the garden irrigation using the rain sensor value as well, that is equally possible.
Operating devices can be smart or unsmart
This practical scenario can be expanded arbitrarily. Let us consider a simple pushbutton on the wall. Installed conventionally, it, for example, moves a blind up or down. No more and no less. A KNX pushbutton or even a room controller in a KNX installation, on the other hand, switches, dims, or moves something or immediately several things – today it can be a blind, tomorrow a light or an entire group of lights. The day after tomorrow it’s the electric door opener or the coffee machine or all of it together. Room controllers with displays can additionally provide many useful information at any time and perform complex tasks such as air conditioning or similar.
Here too, you are maximally flexible: Changing the function of the pushbutton happens purely on the software level. No screwdriver is needed and you do not have to make the change locally on the device. It simply works from the sofa.
With conventional wiring and retrofit systems that use it, the possibilities are limited and sometimes simply not feasible without major effort and corresponding costs.
Often, with conventional installation, you are also restricted by the fact that a location has at most one/two rocker switches or 1/2/3 pushbuttons and thus not so many options. You have no choice but to drill another box if more stationary functions are needed or desired. I have already mentioned the switch batteries and it just looks horrible.
With KNX, you simply assign new functions to the pushbutton and, if necessary, replace it with one with more rockers/buttons. This way, you immediately have the desired options at one location.
Requirement: You want a blinds control.
Conventional blinds control
In a conventional blinds control, the installer will probably mount an anemometer or perhaps even a weather station outside the house. This not exactly inexpensive device will have the task of triggering a wind alarm, upon which the blinds/shutters are retracted, or lowering the blinds when a certain outdoor brightness level is undershot. However, all measurements provided by the outdoor sensor are only known within the blinds control system; it is a closed system, an island. For example, if you want to use the measured brightness additionally for automatically turning on the facade lighting, this is not possible. In conventional electrical installation, the installer would simply install a second brightness sensor for the outdoor lighting – possibly right next to the already existing one.
What happens if you later want to automate the awning so that it shades the terrace from a certain brightness (or temperature)? Right: Either it is not possible at all, or the responsible technician will install a third sensor on the outside wall besides the other two. Apart from the fact that you pay three times for the same sensor value, such constructions are neither aesthetically pleasing nor maintenance-friendly nor flexible.
Blinds control as BUS installation
How would this scenario now be implemented in intelligent building control? Only a single device (weather station) is mounted on the building. The weather station provides measurement values (brightness, temperature, wind, rain, etc.) in the form of telegrams over a bus system. Every participant connected to this bus can receive and process all measurement values arbitrarily. In this case, it would be a blinds actuator for the blinds control, a switching actuator for the outdoor lighting, and a roller shutter actuator for the awning. And if you want to control the garden irrigation using the rain sensor value as well, that is equally possible.
Operating devices can be smart or unsmart
This practical scenario can be expanded arbitrarily. Let us consider a simple pushbutton on the wall. Installed conventionally, it, for example, moves a blind up or down. No more and no less. A KNX pushbutton or even a room controller in a KNX installation, on the other hand, switches, dims, or moves something or immediately several things – today it can be a blind, tomorrow a light or an entire group of lights. The day after tomorrow it’s the electric door opener or the coffee machine or all of it together. Room controllers with displays can additionally provide many useful information at any time and perform complex tasks such as air conditioning or similar.
Here too, you are maximally flexible: Changing the function of the pushbutton happens purely on the software level. No screwdriver is needed and you do not have to make the change locally on the device. It simply works from the sofa.
With conventional wiring and retrofit systems that use it, the possibilities are limited and sometimes simply not feasible without major effort and corresponding costs.
Often, with conventional installation, you are also restricted by the fact that a location has at most one/two rocker switches or 1/2/3 pushbuttons and thus not so many options. You have no choice but to drill another box if more stationary functions are needed or desired. I have already mentioned the switch batteries and it just looks horrible.
With KNX, you simply assign new functions to the pushbutton and, if necessary, replace it with one with more rockers/buttons. This way, you immediately have the desired options at one location.