Ok, now let’s think about the topic from a practical perspective. I’m quite familiar with KNX, but I can’t really come up with a scenario where KNX would clearly benefit us. Here are our floor plans again:
According to the current planning status, roller shutters will be installed everywhere (current planning status!). There will be a large sun sail to shade the central window and the dining room window from the sun. The dining room window facing east and the kitchen window will be in the shade shortly after noon.
A heat pump with cooling function and a ground loop exchanger for the controlled ventilation system are planned. Simple logic functions, such as bypass for the controlled ventilation or controlling the underfloor heating based on outside and return temperatures, are handled by the devices themselves. In winter, when the sun heats the floor, the return flow temperature rises, and the heat pump realizes it needs to heat less because of the external heat input. The ventilation system detects when the bypass should be activated.
Individual room control is pointless, or so everyone says in the pink forum. At least for our KfW55-standard building, it’s probably very unnecessary. Night setback is also not needed.
Energy-saving functions don’t interest me because the investment cost will always be higher than the electricity savings. Conventional smoke detectors will be installed, and please no hysterical discussions about this. There will be no gas, oil, or fireplace in the house. And if the house burns down while we’re away, it’s insured. There will be no photovoltaic system, and I’m not interested in any other extreme energy-saving measures. The washing machine has its own timer. Usually, we just load it in the afternoon and hang the laundry in the evening. It doesn’t need to run for three hours at night because of lower tariffs to save 0.3 cents per wash cycle.
The living/dining/kitchen area will have six roller shutters and four dimmable lights. Three shutters and two lights each will be controlled from switches next to the living room door and the kitchen door. The switches are arranged side by side so that the leftmost switch controls the left side of the room, and so on. So the west, south, and central living areas are controlled from the living room door; the south dining area, east dining area, and east kitchen are controlled from the kitchen door. For shading, only the two roller shutters next to the living room are relevant (south living room, as it is not under the sun sail, and west living room).
Currently, in the old building, we have internal blinds and a large west-facing facade. Apart from the five warmest days of the year, we don’t fully shade the windows. We just want to avoid direct sunlight where we are sitting, working, playing, etc. Depending on the situation, some blinds go up and others go down, and so on.
Constant light regulation is not desired. Even now, we switch lights on and off based on feeling. When we want to go to bed soon, the lights are usually off or more distant lights are on (kind of indirect lighting). I have different lighting preferences than my wife, and when we are together in the room, naturally, a compromise solution applies.
I sometimes work flexible hours, and sometimes I might sleep only four hours one night and seven hours the next day. A rule like “dim after xx o’clock” won’t work.
There is no defined TV lighting plan. It depends on the program. For briefly watching the news, all lighting can remain as is. For a moderately interesting football game, only the direct light is turned off, but indirect lighting can stay. For a ‘Game of Thrones’ episode or a good movie, everything should be off, especially since these often have dark scenes. Sometimes, for example, the hallway light stays on as indirect lighting for the living area (which makes sole hallway lighting with motion sensors pointless now).
Hallway lighting will have switches (two-way switches) next to each door, which can turn the lighting of the respective floor on and off. So yes, exactly one switch next to each door. The two lamps upstairs will switch on and off simultaneously. It is a floor-level switch. At stair landings, of course, there are exactly two switches: one for upstairs and one for downstairs. So, coming down the stairs, you can operate both switches to turn lights off upstairs and on downstairs. Or you turn off the upstairs light at the bottom of the stairs (top switch off = upstairs off; makes perfect sense to me).
Stair lighting could theoretically be controlled similarly, but that also depends a bit on the show effect, right? It could also be done with a timer or motion sensor. And if pets trigger the stair lighting, well, that’s just how it is. At the moment, we don’t have pets.
As for roller shutter control in the living/dining/kitchen areas, as I said before: short press for fully up/down and hold for precise positioning. But half-positioning is discouraged because temperature differences across the glass can cause damage. For example, next to the living room door, pressing the button three times briefly will raise (or lower) the three shutters. All other roller shutters follow the same principle and are arranged next to their respective doors. Only for bedrooms could I imagine a switch with a timer function, and I would only program the opening time for the next morning. I don’t need a closing time. A short press closes the roller shutter. But if I set my alarm clock to 6:53, I also set the roller shutter to 6:53 so that daylight wakes me at the same time (in the future, we will have joint wake-up times again, and my wife won’t have shift work anymore). BUT: all this can be done conventionally and very simply. So: the office (guest room), bedroom, and two children's rooms will have a switch (short = fully up/down) that allows an opening time to be set.
Just to summarize the shading logic during the day: roller shutters go down in the morning when leaving the room/living area and stay down until the first person returns home in the afternoon. This covers the first 10–12 hours of sunlight exposure.
The lighting in many rooms will be dimmable, but I don’t want expensive color lighting effects. The bulbs should have low blue light and good quality.
So, I think I’ve described the most important areas: roller shutters, lighting, heating, and a few other things...
How can automation like KNX help us now? What comfort gains are possible? What should we automate and why?
According to the current planning status, roller shutters will be installed everywhere (current planning status!). There will be a large sun sail to shade the central window and the dining room window from the sun. The dining room window facing east and the kitchen window will be in the shade shortly after noon.
A heat pump with cooling function and a ground loop exchanger for the controlled ventilation system are planned. Simple logic functions, such as bypass for the controlled ventilation or controlling the underfloor heating based on outside and return temperatures, are handled by the devices themselves. In winter, when the sun heats the floor, the return flow temperature rises, and the heat pump realizes it needs to heat less because of the external heat input. The ventilation system detects when the bypass should be activated.
Individual room control is pointless, or so everyone says in the pink forum. At least for our KfW55-standard building, it’s probably very unnecessary. Night setback is also not needed.
Energy-saving functions don’t interest me because the investment cost will always be higher than the electricity savings. Conventional smoke detectors will be installed, and please no hysterical discussions about this. There will be no gas, oil, or fireplace in the house. And if the house burns down while we’re away, it’s insured. There will be no photovoltaic system, and I’m not interested in any other extreme energy-saving measures. The washing machine has its own timer. Usually, we just load it in the afternoon and hang the laundry in the evening. It doesn’t need to run for three hours at night because of lower tariffs to save 0.3 cents per wash cycle.
The living/dining/kitchen area will have six roller shutters and four dimmable lights. Three shutters and two lights each will be controlled from switches next to the living room door and the kitchen door. The switches are arranged side by side so that the leftmost switch controls the left side of the room, and so on. So the west, south, and central living areas are controlled from the living room door; the south dining area, east dining area, and east kitchen are controlled from the kitchen door. For shading, only the two roller shutters next to the living room are relevant (south living room, as it is not under the sun sail, and west living room).
Currently, in the old building, we have internal blinds and a large west-facing facade. Apart from the five warmest days of the year, we don’t fully shade the windows. We just want to avoid direct sunlight where we are sitting, working, playing, etc. Depending on the situation, some blinds go up and others go down, and so on.
Constant light regulation is not desired. Even now, we switch lights on and off based on feeling. When we want to go to bed soon, the lights are usually off or more distant lights are on (kind of indirect lighting). I have different lighting preferences than my wife, and when we are together in the room, naturally, a compromise solution applies.
I sometimes work flexible hours, and sometimes I might sleep only four hours one night and seven hours the next day. A rule like “dim after xx o’clock” won’t work.
There is no defined TV lighting plan. It depends on the program. For briefly watching the news, all lighting can remain as is. For a moderately interesting football game, only the direct light is turned off, but indirect lighting can stay. For a ‘Game of Thrones’ episode or a good movie, everything should be off, especially since these often have dark scenes. Sometimes, for example, the hallway light stays on as indirect lighting for the living area (which makes sole hallway lighting with motion sensors pointless now).
Hallway lighting will have switches (two-way switches) next to each door, which can turn the lighting of the respective floor on and off. So yes, exactly one switch next to each door. The two lamps upstairs will switch on and off simultaneously. It is a floor-level switch. At stair landings, of course, there are exactly two switches: one for upstairs and one for downstairs. So, coming down the stairs, you can operate both switches to turn lights off upstairs and on downstairs. Or you turn off the upstairs light at the bottom of the stairs (top switch off = upstairs off; makes perfect sense to me).
Stair lighting could theoretically be controlled similarly, but that also depends a bit on the show effect, right? It could also be done with a timer or motion sensor. And if pets trigger the stair lighting, well, that’s just how it is. At the moment, we don’t have pets.
As for roller shutter control in the living/dining/kitchen areas, as I said before: short press for fully up/down and hold for precise positioning. But half-positioning is discouraged because temperature differences across the glass can cause damage. For example, next to the living room door, pressing the button three times briefly will raise (or lower) the three shutters. All other roller shutters follow the same principle and are arranged next to their respective doors. Only for bedrooms could I imagine a switch with a timer function, and I would only program the opening time for the next morning. I don’t need a closing time. A short press closes the roller shutter. But if I set my alarm clock to 6:53, I also set the roller shutter to 6:53 so that daylight wakes me at the same time (in the future, we will have joint wake-up times again, and my wife won’t have shift work anymore). BUT: all this can be done conventionally and very simply. So: the office (guest room), bedroom, and two children's rooms will have a switch (short = fully up/down) that allows an opening time to be set.
Just to summarize the shading logic during the day: roller shutters go down in the morning when leaving the room/living area and stay down until the first person returns home in the afternoon. This covers the first 10–12 hours of sunlight exposure.
The lighting in many rooms will be dimmable, but I don’t want expensive color lighting effects. The bulbs should have low blue light and good quality.
So, I think I’ve described the most important areas: roller shutters, lighting, heating, and a few other things...
How can automation like KNX help us now? What comfort gains are possible? What should we automate and why?
Ok, I have read up on the basics of automation. Is this better?
Everything works according to basic, logical principles. If wind speed is above x, then blinds 1, 2, and 3 go up. If solar radiation is above 300 units and wind is below x, then blinds are lowered. The function determines the sun position based on date and location and adjusts the slat angle of the blinds accordingly.
I have a general idea of what exists (window sensors, weather stations, controllable sockets, etc.) and that everything can be programmed. I don’t know exactly which actuators, sensors, and so on are needed or how to wire everything from a hardware perspective. But I’m confident I could program the software myself.
Everything works according to basic, logical principles. If wind speed is above x, then blinds 1, 2, and 3 go up. If solar radiation is above 300 units and wind is below x, then blinds are lowered. The function determines the sun position based on date and location and adjusts the slat angle of the blinds accordingly.
I have a general idea of what exists (window sensors, weather stations, controllable sockets, etc.) and that everything can be programmed. I don’t know exactly which actuators, sensors, and so on are needed or how to wire everything from a hardware perspective. But I’m confident I could program the software myself.
The green bus cable is required for the entire sensor and actuator system.
Simply put: a bus cable goes to every switch (push button), sensor (smoke detector, temperature, etc.).
Power outlets and other consumers (lights) are powered by electrical wiring. No green cable is needed there.
The green cables are basically the nervous system, while the power cables act as the muscles. Both parts are connected via the control cabinet through actuators and so on.
What defines a complete KNX system? That depends on what you want from the start.
I consider a weather station very important, so I would plan for it from the beginning. Having a tablet mounted on the wall (visualization) is nice, but absolutely not essential to prioritize right away.
I don’t see the point of connecting smoke detectors to the bus. The only advantage would be receiving an alert when you’re away if there’s smoke. However, considering the costs, it’s not worth it to me.
Simply put: a bus cable goes to every switch (push button), sensor (smoke detector, temperature, etc.).
Power outlets and other consumers (lights) are powered by electrical wiring. No green cable is needed there.
The green cables are basically the nervous system, while the power cables act as the muscles. Both parts are connected via the control cabinet through actuators and so on.
What defines a complete KNX system? That depends on what you want from the start.
I consider a weather station very important, so I would plan for it from the beginning. Having a tablet mounted on the wall (visualization) is nice, but absolutely not essential to prioritize right away.
I don’t see the point of connecting smoke detectors to the bus. The only advantage would be receiving an alert when you’re away if there’s smoke. However, considering the costs, it’s not worth it to me.
I thought so... so you are still far from saying, "I have dealt with KNX," but that’s okay.
I would run the green cable everywhere, including to the power outlets… why?
Because it costs almost nothing, but the cable will be available everywhere. You will regret it deeply if you need the cable in some corner and it’s not there.
It can also happen that during construction a cable gets damaged and you can’t access that spot later… if you have laid it everywhere, you can simply start from the other end and supply the room from there… so, lay an open loop per room and bring the cable to every single outlet, like pearls on a string.
There is no such thing as a complete KNX system since it is modular… in other words, you can have many or few devices… both would be complete.
Just make a list of functions you need for each room… then you can see from there.
I would run the green cable everywhere, including to the power outlets… why?
Because it costs almost nothing, but the cable will be available everywhere. You will regret it deeply if you need the cable in some corner and it’s not there.
It can also happen that during construction a cable gets damaged and you can’t access that spot later… if you have laid it everywhere, you can simply start from the other end and supply the room from there… so, lay an open loop per room and bring the cable to every single outlet, like pearls on a string.
There is no such thing as a complete KNX system since it is modular… in other words, you can have many or few devices… both would be complete.
Just make a list of functions you need for each room… then you can see from there.
Alright, in a first basic version, the KNX cable should be installed everywhere. At least one KNX bus coupler should be placed next to every door. There will be 3 venetian blinds in the living room and roller shutters everywhere else. Venetian blinds and roller shutters require wind sensors, measurement of solar intensity (= weather station?), and possibly a weather forecast for the day.
In my opinion, there should be an away mode, which is centrally controlled at the entrance. In this mode, all roller shutters switch to automatic (venetian blinds open or closed depending on heating or cooling season), and certain power outlets are disconnected (stove, oven, TV, etc.).
For the hallway and stairs, we want to try motion or presence detectors. I still want to install the flush-mounted bus coupler so that switching to manual control later is possible.
It probably makes sense to make all light sources dimmable for future changes. Maybe later I want to have only half the light on in the hallway, for example.
Possible expansion stages would be:
- Window contacts (mainly to indicate at the entrance if a window is still open when leaving the house – or are there other useful functions for window contacts?)
- Integration of smoke detectors
For the front door, I’d actually prefer to keep it conventional. Mechanical key.
We would probably install a Wolf CWL (300 or 400) and a Rotex HPSU compact. The latter has a cooling function and a hygiene water storage tank. How can these be sensibly integrated, or are these devices not suitable? We might also switch to a ground-source heat pump (model unknown).
The washing machine, dryer, and kitchen appliances will all be newly purchased, so a model with bus integration could be chosen here.
One more question: I thought KNX should be wired in a star topology? Now you mention an open ring topology per room? Should the power wiring be star-shaped and the KNX wiring ring-shaped per room?
In my opinion, there should be an away mode, which is centrally controlled at the entrance. In this mode, all roller shutters switch to automatic (venetian blinds open or closed depending on heating or cooling season), and certain power outlets are disconnected (stove, oven, TV, etc.).
For the hallway and stairs, we want to try motion or presence detectors. I still want to install the flush-mounted bus coupler so that switching to manual control later is possible.
It probably makes sense to make all light sources dimmable for future changes. Maybe later I want to have only half the light on in the hallway, for example.
Possible expansion stages would be:
- Window contacts (mainly to indicate at the entrance if a window is still open when leaving the house – or are there other useful functions for window contacts?)
- Integration of smoke detectors
For the front door, I’d actually prefer to keep it conventional. Mechanical key.
We would probably install a Wolf CWL (300 or 400) and a Rotex HPSU compact. The latter has a cooling function and a hygiene water storage tank. How can these be sensibly integrated, or are these devices not suitable? We might also switch to a ground-source heat pump (model unknown).
The washing machine, dryer, and kitchen appliances will all be newly purchased, so a model with bus integration could be chosen here.
One more question: I thought KNX should be wired in a star topology? Now you mention an open ring topology per room? Should the power wiring be star-shaped and the KNX wiring ring-shaped per room?
S
Sebastian7929 Aug 2016 09:54Just wait for the price your electrician will give you – you’ll quickly drop that idea.
You’re building with a general contractor, right?
You’re building with a general contractor, right?