Fan coil units, air conditioners and other climatic equipment are quite multifunctional automation systems that control valves, electric motors, sensors, digital or graphic displays, timers and memory, all kinds of protective and warning circuits, a remote control unit, and so on. On the other hand, modern electronics allows you to place much more complex devices on one small printed circuit board - TVs, PCs, smart home complexes, telephone exchanges, and so on. The concentration of all electronic components in one module gives a lot of advantages:

• it's smaller than a few niche boards, requires less space and materials, and is therefore cheaper;
  
• it is more reliable, because there are fewer conductors and connections;
  
• this allows you to repair the installation as a whole in a matter of minutes - without diagnosing each circuit and circuit, replace ALL electronics at once and return the equipment to work, and then repair the relatively expensive board itself, but identify and eliminate a specific local malfunction without haste and in convenient conditions laboratory or service center.
  

Control boards can be for certain models of HVAC systems, and for entire product lines of one manufacturer, as well as universal, combining, for example, a fan speed controller with a single-phase asynchronous motor up to 300 W, a 3-way valve drive controller for 220 V AC and 24 V DC, the receiving part of the IR remote control, a digital thermometer with an external sensor, a timer with programming for switching on several modes, etc.