Depending on the device type and available interfaces, there are two main ways:
1.) Switching the power supply
If no other interface is available, the easiest way to turn on an air conditioner or FCU is to simply turn off the power when the room is left.
Powerful presence detectors such as ecos PM/230V/5T are suitable for this purpose.
Although this approach is very effective in terms of energy savings , it also has some disadvantages.
Initially, the room may heat up considerably and require a longer cooling time when used again.
Second, there is no standard behavior for all types of air conditioners once the power is restored:
- Some air conditioners will resume operation in the last selected cooling mode and at the last set temperature
- Other air conditioners simply go into standby mode, and the user must manually reactivate cooling . While this may be desirable in some buildings, it doesn't score highly in terms of user comfort.
In this case, the external sensor switches the power supply to the air conditioning units and must have a relay rated for the load. Typically, 230 V sensors are used in this application.
2.) Use reset interface for external controls
Fortunately, more and more air conditioning systems and room thermostats today have an input contact to which an external control, in particular a sensor or a switch, can be connected.
In many cases, these inputs are designed as potential-free inputs.
The air conditioning or climate control systems (and/or external thermostats) can be programmed to lower the set room temperature by a certain degree, e.g., +5°C, when you are away. This way, the air conditioning system does not shut down completely, but maintains the room at a level from which it cools down quickly after reuse, still achieving significant savings.
Typically, sensors such as ecos PM/24V/5T or occy can be used in this scenario.
