Air Conditioning Repair Certification (ETI) 2025 – 400 Free Practice Questions to Pass the Exam

In an air conditioning system, temperature control primarily occurs through thermostat settings. The thermostat serves as the control center for the system, monitoring the indoor temperature and signaling the air conditioning unit when to turn on or off in order to maintain the desired level of comfort. When the ambient temperature rises above a set point, the thermostat activates the air conditioning system to cool the space down. Conversely, when the temperature drops to the desired level, the thermostat turns the unit off. This method allows for precise and efficient management of climate control in a building, ensuring comfort for the occupants.

While adjusting the expansion valve, refrigerant levels, and changing compressor speed can all impact the overall efficiency and operation of the system, these actions do not directly control the indoor temperature like the thermostat does. The expansion valve regulates the flow of refrigerant and the compressor speed may adjust depending on the system design, but ultimately, it is the thermostat that coordinates temperature regulation effectively.