Technicians usually have air conditioner troubleshooting guide in them after having gone through different kinds of problem in the field. Central air conditioning system usually have electronic control system that indicate the type of error or failure in the system.
Electronic controls are becoming more sophisticated and greatly help in troubleshooting of big system. There are electronic systems that can be remotely controlled or monitored and they are usually installed in mission critical type of environment.
Visiting HVAC events and trade shows are one of the best way to equip yourself with the latest happenings in the air conditioning and refrigeration field. See the listing of events for year 2017-2018.
Direct Expansion System uses components such as the compressor, evaporator coil, metering device and condenser coil to expand the refrigerant and cool the room.
Zigbee is another standard wireless option to control the air conditioners in homes or buildings.
Here are the air conditioners frequently asked questions and answers.