Renovations open up the chance to keep up with the times and to install home automation. But is it that easy? What technical challenges will the client face? And where are the limits of what is possible? Christian Ziegler from Hettlingen has taken the leap into the future and automated his 30-year-old family home.
Hettlingen is a tranquil village at the gates of Winterthur. The Ziegler family lives and works here in a quiet single-family home district. Both Christian and Manuela Ziegler are qualified electricians and together they run All-Com AG. The company is based in the family home and specializes in building automation. Christian Ziegler remembers: “When I started my own business, I was almost burned at the stake. ‹Smart homes? Nobody needs that!', it was said in many places. But I felt that home automation is normal. It's not devil stuff." The 49-year-old father of two daughters was not deceived by his feelings: the company has been successfully active in this field for 16 years. "We mainly automate new buildings, because that's actually part of the standard today," says Christian Ziegler. The situation is somewhat different for existing buildings. "Automation is rarely an issue in conversions and renovations." He can only guess why: "Many property owners don't seem to be aware that this is feasible."
Not difficult, but laborious
In their own house, which they bought around six years ago, the Ziegler family has proved the opposite and have automated everything possible over the past two and a half years: room temperature control, shading, multimedia systems, devices such as the electric lawn mower, who does his rounds independently in the garden in front of the seat, or the lighting. That wasn't difficult to implement, just expensive. Christian Ziegler explains: “We only had equipment plans available to us, i.e. plans with sockets, switches and junction boxes drawn in, but without wiring. So in each room we first had to unscrew the installed equipment to figure out what we needed. Then we ordered the material and installed it. Because of the children we could not leave the electrical installations open. So we did everything twice: first screwed it on and checked what was needed, then screwed it back on, ordered it, screwed it on again, installed it and finally programmed it.”
Networked thanks to KNX
For their home automation, the Zieglers have opted for KNX – a made-up word, adapted from Konnex – and the associated automation software ETS. The bus system separates the device control and the power supply from each other into two networks: the power network for the energy supply with AC voltage and the control network known as the field bus or bus line with DC voltage. All devices to be controlled are connected via this bus and exchange data. The function of the bus participants is determined by specific programming. Actuators are installed between the participants and the mains voltage, i.e. technical drive units that convert an electrical signal into mechanical movements. These actuators are also connected to the KNX bus and receive their data in the form of telegrams directly from a sensor, for example from a motion detector or a thermostat.
500 producers, one standard
The bus system is standardized and has been on the market for 30 years. Therefore, all possible trades from different manufacturers can be networked with it - as long as they have the appropriate certification from the KNX Association. Christian Ziegler says: "There are around 500 producers worldwide whose devices support the KNX standard." There is also the option of connecting wired with wireless components. This is an advantage above all when pipelines are not laid optimally. This was the case, for example, with the blinds in the family house: They were already electrified and could therefore easily be converted to automated control, but the existing 230 V piping was unfavorable. This is where decentralized wireless actuators come to the rescue.
A house full of scenes
Conventional light switches can hardly be found in the Ziegler family home. Most have been replaced by KNX buttons whose LEDs light up yellow, blue and purple. Unlike a light switch, a button does not close any circuits, but only gives impulses to activate a process - or a scene, as Christian Ziegler calls it. He explains: "For us, yellow means light, blue blinds and violet scenes." The electrician programmed the latter himself. "That's not really difficult either, but rather hard work," he says. "If we want to define a new scene or change an existing one, we can do it very easily on a laptop, tablet or cell phone." But a one-week KNX basic course is still not a bad investment. «The rest is learning by doing.» In the dining area, Christian Ziegler presses on different scenes. The dinner scene brightens the lamps above the dining table, the dinner scene dims it again, the everyday scene turns on extra lights in the kitchen. All of these scenes can also be activated or deactivated on a smartphone or tablet via an app. ❭ Christian Ziegler pulls out his smartphone and opens the corresponding app. The menu shows the floors and the individual rooms. He navigates to his daughters playroom and taps on the playroom scene, which turns on the lights and music there.
Only purple buttons left!
The next stop on the tour is the entrance, where Christian Ziegler activates the "briefly absent" scene. “We press this button when we go shopping, for example. The light is turned off, the music system is switched off, the shading and the camera on the seat are activated,” he says. "And if we forget, we can select the scene later on our smartphone." Inside the house this works via WLAN, outside thanks to a VPN connection to the server, which is located in the basement. He presses the button next to the stairs to the upper floor and selects "Go up". The scene is defined in such a way that only individual lights are on in the kitchen, the lamps by the stairs are getting brighter. Once upstairs in the bedroom, he presses a button on the button above the bed. The "Good night" scene turns off all the lights in the house and activates the Sonos box. Quiet sounds ring out. "That's the music we fall asleep to," says the family man, summarizing: "That's actually how we work. For us there are practically only the purple buttons. »
There are pitfalls too
The tour shows: Subsequent home automation can be done with little or no structural work. Christian Ziegler: «We didn't change anything structurally, just drilled a few holes here and there. I didn't pick up a mallet and knock slits in the walls." But there are some pitfalls. "If you don't know, for example, where the lines are going, this has to be determined first." In addition, you need time and money. “The original electrical installation in our house cost around 70,000 francs when it was built in 1991. That was quite a lot back then. When I look at the components we installed and the time spent, I'm easily twice that amount," Christian Ziegler calculates. "In a new building," he estimates, "the additional costs for electrical installation and automation would amount to around ten percent of the total construction cost."
It's all about the basics
There are only a few limits to automation in existing buildings. Christian Ziegler says: "Of course it's easier if the basics are already in place. For example, electric blinds that can easily be automated.» If such basics are not available - for example in an apartment building from the 1970s - it gets expensive. “You would have to supply electricity to the blinds first, for example. In such buildings I would recommend waiting until a complete renovation is due anyway. Because then you knock slots in the wall anyway or lower the ceiling and you can install the components for the automation at the same time.”
A fun gadget
The question arises as to whether this not inconsiderable additional investment is worthwhile, for example when it comes to saving energy. Christian Ziegler says no. "Additional building measures would have to be taken for this, such as an energetic roof renovation, which we did, however." Automation alone has little impact on energy consumption. “We might save some energy if we travel to the Engadine for a few days. Then we lower the room temperature and don't raise it again until we're on our way home." But saving was not the reason why the family decided to make their house smart. "I think that's just part of it these days. In addition, our house serves as a kind of showroom for our customers.» He is convinced: “You cannot sell building automation at the table. The customers have to experience that.” And of course an intelligent house also brings more living comfort. Christian Ziegler: «If one of our garage doors is open, I see a red bar on my smartphone. I can close the gate with a swipe without having to get up. That's comfortable. It's also really fun to live in an automated house. In any case, I don't want to miss it anymore."
