The phrase "Big brother is watching you" is more relevant today than ever: of course, we have not yet reached total surveillance, but the interaction of engineering systems can be seen with your own eyes. A huge number of sensors connected to the controllers ensure the safety of property, personal safety, comfort in a smart office, home, car or public building.
Smart home sensors are conditionally divided into two categories: motion sensors and environmental monitoring sensors.
Motion sensors
They are included in the security systems of intelligent lighting. Sensors that track the movement of objects are classified as intelligent. They scan several zones simultaneously, determining the volume, mass of the object and the distance to it. The security system with a connected computer and installed software monitorsmovement of an object in a building and determines its exact location.
Two types of sensitive elements used in security systems - an acoustic glass-break detector and a reed switch - do not belong to the category of trackers.
Acoustic detector and reed switch
The operation of the reed switch - an electromechanical device - occurs when the contacts are opened. This is accompanied by the activation of the alarm and the sending of a message to the first responder. Reed switches are wireless and wired. They provide a high level of security.
Acoustic detectors - sensors for "Smart Home" that react to sound when glass is broken. In the event of a break-in, the recorded signal is sent to the security system console.
Motion and presence sensors
The principle of operation of motion sensors is based on the technology of tracking changes in ultrasonic and infrared fields. Such sensors are widely used in security systems and automatic light control. The infrared sensors used in lighting systems are equipped with light sensors. Some models of Smart Home sensors have the functionality of remote IR signal receivers.
Presence sensors work similarly to motion sensors, but are more sensitive to parameter changes. In addition to infrared, there are capacitive and inductive models. The functionality of the latter allows you to track metal objects in serviced areas. High sensitivityPresence indicators prevent their use in security systems - instead, they are installed in home appliances and lighting control systems.
Sensor Features
Despite all its advantages, the main disadvantage of smart home sensors is the ability to bypass them. For example, infrared sensors that respond to changes in body temperature can be easily fooled.
For this reason, to ensure full protection, security officers recommend installing several sensors of different spectrums on entrusted objects.
It is practically impossible to build a full-fledged Smart Home control system only on presence and motion sensors. The signal is not received if the object does not move for a long time, therefore, there is no certainty that the room is empty.
The Smart Home system software records the number of people in the room and saves the data. Photoelectric sensors installed in the corridor or opening determine whether a person has left or entered. Such sensors capture the movement of objects only in a narrow beam spectrum.
Similar sensors are installed on barriers, garage and entrance automatic gates. The equipment for the "Smart Home" fixes whether someone passed through the gate or not, automatically closing or opening them.
Photoelectric sensors are being replaced by laser sensors at specially protected facilities due tounlimited budget. Their main difference from optical analogues is high sensitivity and absence of errors in data reading. They work at a great distance and react even to small objects.
Temperature Devices
These are sets of sensors for "Smart Home", designed for the functioning of engineering systems. Modern heating appliances are equipped with various types of temperature devices.
Outdoor sensors monitor the air temperature outside. The information received from them and the home weather station allows you to set the optimal mode of operation of the ventilation and heating system.
Smart Home room temperature sensors installed on the return and supply lines of the coolant maintain the optimum temperature in the room.
Environment sensors
Gas leak sensors alert you to a leak with a shrill signal. The flow of fuel will be stopped if there is a shut-off valve with a solenoid valve at the inlet.
Fire sensors detect smoke in the air in the room or an increase in temperature above the established norm.
Leak sensors shut off valves embedded in the plumbing system when water enters the monitoring elements.
Water pressure sensors monitor the pressure in the pipeline. The Smart Home system automatically decides to turn off the water when pressure changes critically.
Dampness sensor detects the level of humidityair in the room and reports the presence of leaks. It can notify you of problems with heating or open windows.
Rain sensors built into the system capture the readings and send them to the home weather station, controlling the operation of other systems, including automatic watering of the home area.
Selection criteria
The sensor connection method is one of the main selection criteria. There are two options: wired and wireless, but the first is considered technically and morally obsolete and is not used in modern systems.
For wireless connection can be used:
- Radio channel. It is used extremely rarely, because it has a large number of shortcomings, and therefore loses its relevance.
- Z-Wave channel. Combines up to 232 devices. The best low-cost option for connecting a small number of devices.
- ZigBee channel. Links up to 6,500 gadgets. This is the most common Smart Home technology and is considered standard.
- Wi-Fi. Not the most convenient way to connect sensors, since signals from different devices may overlap.
Modern Smart Home technologies support several options for connecting sensors, but it is preferable to choose a specific one.
The second selection criterion is the range of settings. Before operation, sensors are adjusted to normal and critical data limits - the response range. The setting is important for sensors responsible for climate andterritory security.
When choosing sensors for the Smart Home, the manufacturer is taken into account. The modern market offers a wide range of equipment, there are clear leaders whose products are highly reliable.
Installation Options
Electrical installation products for "Smart Home" are available not only in the form of standard sensors, but also in the form of sensors for installation in suspended ceilings. This method of installation allows you to place the sensors flush: outwardly they do not differ from halogen lamps.
The installation itself can be carried out in two ways: wall and ceiling. The first is often resorted to when installing the system in rooms with high ceilings. The optimal height for placing sensors is 2-3 meters.
When mounting, the maximum load is taken into account - the number of devices simultaneously activated by the sensor command. Presence sensors can burn out due to the high load exerted on them by fluorescent and LED lamps. The optimal load on dimmers and sensors connected to LED lamps should be 2-3 times lower than the calculated load power.
Settings
Sensors before installation are adjusted using the regulators located on the body. This is how the trigger thresholds are set: sensitivity levels, illumination levels, delay time and special operating modes.
The viewing angle of the sensor is adjusted in the same way. This is done using plastic overhead curtains,included in the kit - they are called signal cutoff filters. The viewing angle is corrected by breaking out a part of the plastic curtain along the notches.
How much does a "Smart Home" cost
The final cost of the project is affected by the quantity and reliability of equipment, a set of modules, purchased multimedia devices, features of engineering systems and wiring in the house.
The price may also vary depending on the number of utility and residential premises, the total area of the building, the number of windows and the square footage of bathrooms.
No less important is the number of functions, modification of equipment, manufacturer, specifics of the work being done. For this reason, there is no upper price limit.
Some sensors are required to be installed - for example, security systems and fire extinguishing systems. You can refuse some without losing the quality and convenience of the system.
A lot depends on individual needs. The technology may include various functions, among which remote switching on and off of lighting, heating of the "Smart Home", automatic switching on of music, opening and closing of curtains are called not very popular. Their exclusion from the project saves from 20 to 80 thousand rubles.
The situation is similar with other subsystems. For the installation of equipment will have to pay 10-20% of its cost. The average price for a Smart Home system is 400,000 rubles, but the maximum cost can be much higher. Luxurytechnology kits can cost millions.
