How does the FDECU inside check valve affect refrigerant flow in cooling mode?

In cooling mode, the function of the FDECU (Frequency Drive Electronic Control Unit) and the associated check valve is critical for the control of refrigerant flow. The correct answer indicates that the check valve does not permit flow in situations where backflow might occur. It is designed to prevent refrigerant from flowing in the reverse direction, which ensures that the flow remains stable and efficient in the intended direction necessary for the cooling process.

In cooling mode, if the refrigerant were to backflow, it could disrupt the cycle and reduce the system's efficiency, potentially leading to compressor damage and reduced cooling effectiveness. The check valve's primary role is to maintain a one-way flow of refrigerant, aiding in the prevention of this backward movement and contributing to the overall reliability and performance of the HVAC system.