Abstract: A humidity control method is provided for a multi-stage cooling system having two or more refrigerant circuits that balances humidity control and cooling demand. Each refrigerant circuit includes a compressor, a condenser and an evaporator. A hot gas reheat circuit having a hot gas reheat coil is connected to one of the refrigerant circuits and is placed in fluid communication with the output airflow from the evaporator of that refrigerant circuit to provide additional dehumidification to the air when humidity control is requested. The hot gas reheat circuit bypasses the condenser of the refrigerant circuit during humidity control. Humidity control is only performed during cooling operations and ventilation operations. During a first stage cooling operation using only one refrigerant circuit and having a low cooling demand, the request for humidity control activates the hot gas reheat circuit for dehumidification and activates a second refrigerant circuit to provide cooling capacity.

Abstract: A humidity control method is provided for a multi-stage cooling system having two or more refrigerant circuits. A hot gas re-heat circuit having a hot gas re-heat coil, an evaporator and a compressor, such as the evaporator and compressor utilized in one of the refrigerant circuits, is provided. The hot gas re-heat coil is placed in fluid communication with the output airflow from the evaporator of the re-heat circuit. Humidity control is performed during cooling operations and ventilation operations. During a first stage cooling operation using only one refrigerant circuit and having a low cooling demand, the request for humidity control activates the hot gas re-heat circuit for dehumidification and activates a second refrigerant circuit to provide cooling capacity. During a second stage cooling operation using multiple refrigerant circuits and having a high cooling demand, the request for humidity control is suspended until completion of the second stage cooling demand.