Smart Home case study: children’s room

You shouldn’t start planning your rooms from the aspect of functional elements, such as lighting, heating, shading, and so on… let’s start from everyday situations and describe them to the contractor since it’s a liveable home you want at the end, not a completed tick list.

a) Daytime

  • Lighting is to be on only when it’s necessary according to the external light sensor. And if it’s is, all the lights can be on because the kids are playing. This lighting is not necessary during a power outage.

  • Blinds must go up at wake-up time except for weekends or when the school holiday option is set.

  • playing music is allowed

b) Before bedtime

(later on the case of “I’m on my computer, leave me alone”)

  • As for lighting only the mood lighting option is to be on, but only when the external light sensor says so. For example, during preparations for afternoon naps it’s not needed. It is unnecessary during a power outage.

  • Blinds are to go down and full shading is to be activated.

c) Sleep time

  • Only night lighting must be switched on. It is also needed during power failures.

  • Music stops and cannot be restarted.

General lighting (normal and before bedtime) is controlled by the presence sensor. If there is any motion in the room and there isn’t enough light according to external light conditions, lights are on. The presence sensors should be set at the sensor or at the home management system with a delayed activation. This way a lack of movement will not trigger the OFF mode immediately. For us, a delay of 120 sec works best.

Reading lamps are manually operated.

d) Shading

Here comes the complicated part, shading, which is controlled by similar principles in the other rooms used for sleeping.

  • Blinds must go up at wake-up time if it is not a weekend or the school holiday option is not active, but it also has to take into account that there is no strong wind.
  • If there is a strong wind, the blinds are to go down and are set in a middle position (allowing light in), BUT only when it is not sleep time.
  • Based on the orientation of the room the system should check every 15 minutes whether shading is needed
  • (orientation is crucial because in west facing rooms shading does not need to be dealt with before 3 pm.) it can decide whether level 1, 2 or 3 shading is the most optimal (level 3 is the closest to blinding but it is still not dark).
  • When there is no need for shading BUT no one is asleep OR there is no strong wind, blinds are to roll up.

To sum up

  • Usually there is no light switch, only ‘I am inside’, ‘before bedtime’ and ‘sleep time’ switches.

  • Blinds operate automatically according to everyday scenario / external light /wind, we’ve never had to touch it.

  • If you can leave the house through the room, the system should also check the door. The blinds should not be lowered when the door is open.

Coming up next: living room

Introduction: smart home tips for beginners

A few more things clients usually realise only in retrospect

  • many devices run on 12V instead of 220V. This means that you will need to use a power transformer. But transformers emit some noise, so you must think through where to hide your transformer and whether the noise there will bother you. Less noisy transformers are more expensive.

  • sensors are typically low voltage devices. You can have the sensors set up in a bus system or in a star network. The difference between the two is that in a bus topology, switches and sensors are, theoretically, connected to “one” wire. In a star topology, every switch and sensor (the typical inputs) has its own wire. From this description, the bus system may seem preferable because it needs fewer cables. This is not necessarily true. You should choose between the two topologies considering your needs and the size of your wallet. But star networks certainly require a lot of cables that must be run through the house. All of that wiring requires a lot of space. In today’s modern homes it is particularly challenging to ensure airtightness while running your wires through the house. What’s good for one is surely bad for the other. It’s physically impossible to have airtight sealing for a bunch of round cables running together. There are actually some solutions, but you must pay attention to the problem.

  • always get extra cables everywhere. Some things will be missing even with the most thorough planning.

  • wireless systems are all the rage now. But if your internal walls are light-weight drywalls attached to a metal framing, your home will not be particularly wireless friendly. The enclosed metal cage shields invisible waves. Reinforced concrete ceilings have the same effect. Make sure that you have cables fed through these walls and ceilings to avoid having to drill holes later.

Switches

Non-technical home-owners typically distinguish between three basic types of switches:

  • traditional switch: you can tell by looking at it that it is in the ON position. Its main disadvantage is that it’s not compatible with automatic operation. After all, the smart home can’t get up and walk over to flip the switch to the on/off position.

  • blind switch: I just call it the mouse in the wall. You hear a click when you press it, and when it’s released, it flips back to its original position. It has the advantage of allowing you to program a double click function as well (depending on your home’s system). This means that, for example, a simple dual switch can be used to produce four different scenarios.
  • multiple-switch switch: there are many different types; some even come with a built-in display. It gives you an opportunity to put even more buttons on the wall that only you will be able to use. Honestly speaking, I have yet to find one that’s really usable. Wherever we needed more buttons, we just placed several blind switches under one another.

Mounting height for switches:

  • about 120 centimeters: this is the classic height, but I have yet to figure out its benefit

  • 90 centimeters: this is where we placed the switches in our home. At this height, children can also reach the switches and get used to using them. A further advantage is that adults don’t need to raise their hand to operate the switch; you can simply hit it as you walk by.

PS for the switches: to mark the function of the switches, we bought some plain, solid-colour self-adhesive wallpaper and used craft punches. I needed the craft punch to make the shapes look nice. The buttons were given one or two moons, or one or two suns in accordance with the light intensity. Even kids understand that the two suns mean more light.

Things to know about networks

  • it makes sense to set up a gigabit network access point in every room of the house (maybe not in the restroom). Smart appliances are now appearing even for the kitchen. If they have a LAN port, always use a wired connection and not Wi-Fi. This will reduce electrosmog.

  • windows and drywalls vs Wi-Fi: you don’t really hear about this, but drywalls use metal studs, which really shield the Wi-Fi signal. The same is true for metal-framed windows. You either need to use a high-quality Wi-Fi router or be prepared to boost your Wi-Fi signal several times.

  • use static IP addresses for your devices. In larger households as many as 30-50 devices may connect to the internet. Make a list of your IP addresses for example in Google Docs to make it easy to find and update.

Coming up next: case studies by the room

Introduction – or what makes a home smart

How can this practical guide help you?

I’d like to begin by saying that this blog does not approach the concept of intelligent homes from a technical perspective. I’d like to offer you a little help by showing you how functional descriptions should be taken into consideration so that what you get at the end, is NOT a haunted house but a home that works in accordance with your wishes.

The things described in this blog should be used to ensure that

  • the contractor does not take you for a fool
  • the contractor can see whether the system to be introduced is suitable for the job
  • the contractor can decide whether he/she can fulfill your requirements
  • you do not pay two-three times as much as planned for the system programming
  • you will not tear your hair out a few months after the system is set up, and your significant other will not move out saying the smart home is more irritating than helpful

Sensors

Just like for any other job, appropriate tools are necessary for setting up a smart home. In our case, these tools are the sensors. Without sensors, the home is not really smart, as processes and events are usually tied to changes. You can think of sensors as ingredients for cooking. If you only realise retrospectively how it should have been done, your dish may turn out inedible and you may need to start from scratch.

Sensors/inputs not linked to particular rooms:

  • light sensor(s): their job is to tell you the intensity of light measured in lux. For houses, north-facing light sensors are recommended to control lighting, and south-facing ones to control shading. North-facing sensors in the shade give you a steady light intensity reading, while the south-facing ones can trigger the shades should the sun come out unexpectedly. If you use south-facing sensors to control lighting, even the last rays of sun may be detected by the sensors as bright enough to keep the house unlit. For apartments, semi-detached and attached buildings, the outdoor sensor should be installed wherever it gets the most sunlight.
  • wind sensor: if a sudden storm hits, the wind sensor prevents the window from breaking by lowering the shades. It also prevents the sunshade from being torn off the wall.
  • power outage sensor: (can be a simple magnetic switch) the home’s smart features only operate with power. For this reason, an uninterruptible power supply (UPS) is strongly recommended to bridge power failures. If the UPS is used for more than emergencies (for example for emergency lighting), a signal must tell it which light is to be turned on during a power failure and which isn’t.
  • precipitation sensor: to control sprinklers/irrigation systems

Sensors/inputs to be used in every room:

  • presence sensors: they differ from motion sensors in that they detect smaller movements such as breathing. Before buying, always test their operation in a quiet space, because they emit a clicking noise due to their relays continually switching on. The types with lower noise levels are more expensive… If possible, their sensitivity should also be tested (do they really detect breathing or do they need to be waved at? and what is their range?).
  • temperature sensor: can be used to control heating but may also come in handy as a fire alarm (it’s strange for a room to have temperatures over 30 degrees Celsius). In order to control the shades, outdoor temperature sensors should also be used. After all, if the weather’s cold but the sun is shining, you can save some energy you would use for heating.
  • water sensor: pipe bursts can cause significant damage; a water sensor can shut off the main valve immediately upon detecting a water leak. But you should inform your cleaning staff about the sensor, because mopping the floors with plenty of water may falsely trigger the system.
  • door and window sensors: despite what you may think, these are not only good for intruder detection. For example, it’s good if the system can tell from the open patio door that you’re on the patio, and the automatic shades do not lock you out when you’re working on your tan.

Coming up next: avoiding hidden problems; things to know about networks; switches…