ESCO Air Conditioning Practice Exam

With an automatic expansion valve, an increase in evaporator load will cause the:

1. Automatic expansion valve to close

2. Automatic expansion valve to open

3. Compressor to shut down

4. System to defrost

The correct answer is: Automatic expansion valve to close

When the evaporator load increases, the temperature inside the evaporator decreases. This causes the automatic expansion valve to close in order to restrict the flow of refrigerant into the evaporator, preventing a buildup of too much refrigerant. This allows for more precise control of the amount of refrigerant entering the evaporator, ensuring proper cooling efficiency. The other options are incorrect because the compressor does not shut down and the system does not defrost in response to an increase in evaporator load. Also, since the goal of the automatic expansion valve is to regulate the flow of refrigerant and maintain proper evaporator pressure, it would be counterintuitive for it to open further when facing an increase in load.