What are two symptoms of a rooftop air conditioning system with a condenser fan-cycle control stuck in the closed position during low ambient conditions?

When a rooftop air conditioning system experiences a condenser fan-cycle control that is stuck in the closed position during low ambient conditions, it can lead to a phenomenon known as low refrigerant flow through the condenser.

This situation will result in low discharge pressure because the refrigerant is unable to release heat effectively due to insufficient airflow over the condenser coils. With the fan not operating, the refrigerant cannot properly condense, causing a decrease in the pressure at the discharge side of the compressor.

Additionally, these low ambient conditions combined with poor airflow will lead to a low suction pressure as the evaporator is not getting enough refrigerant to absorb heat from the indoor environment effectively. This reduced refrigerant flow can cause the evaporator to become underloaded, resulting in a drop in suction pressure.

Recognizing these symptoms is crucial for diagnosing issues with system performance and ensuring efficient operation of the HVAC system. If the control is functioning correctly, proper airflow is essential for maintaining both discharge and suction pressures within the desirable range.