System and method for using hot gas re-heat for humidity control

A heating, ventilation and air conditioning (HVAC) system for an interior space, the HVAC system comprising:

• a first refrigerant circuit having a first compressor, a first condenser and a first evaporator;
• a second refrigerant circuit having a second compressor, a second condenser and a second evaporator;
• a hot gas re-heat circuit including the first compressor and the first evaporator, the hot gas re-heat circuit further including a re-heat coil positioned adjacent to the first evaporator, and the hot gas re-heat circuit being configured, when enabled, to disable the first refrigerant circuit by bypassing flow of refrigerant to the first condenser and to permit refrigerant to flow from the first compressor through the reheat coil to the first evaporator;
• and
• a control system to control operation of the first refrigerant circuit, the second refrigerant circuit and the hot gas re-heat circuit, the control system being configured to enable the first refrigerant circuit and the second refrigerant circuit in response to receiving only a demand for humidity control and being configured to enable the hot gas re-heat circuit in response to receiving only a demand for humidity control.

A heating, ventilation and air conditioning (HVAC) system for an interior space, the HVAC system comprising:

• a first refrigerant circuit having a first compressor, a first condenser, a first expansion device and a first evaporator;
• a second refrigerant circuit having a second compressor, a second condenser, a second expansion device and a second evaporator;
• a hot gas re-heat circuit including the first compressor and the first evaporator, the hot gas re-heat circuit further including a re-heat coil positioned adjacent to the first evaporator, and the hot gas re-heat circuit being configured, when enabled, to disable the first refrigerant circuit by bypassing flow of refrigerant to the first condenser and to permit refrigerant to flow from the first compressor through the reheat coil to the first expansion device and first evaporator;
• a control system to control operation of the first refrigerant circuit, the second refrigerant circuit and the hot gas re-heat circuit, the control system comprising two different control algorithms selectable by a user to control the HVAC system;
• and
• wherein the two different control algorithms includes a first control algorithm being configured to enable the first refrigerant circuit, the second refrigerant circuit and the hot gas re-heat circuit in response to demands for humidity control and stage one cooling and a second control algorithm being configured to enable the first refrigerant circuit, the second refrigerant circuit and the hot gas re-heat circuit in response to a demand for only humidity control.