System and method for using hot gas reheat for humidity control

A method for operating a humidity control and cooling system, the method comprising the steps of:

• providing a humidity control and cooling system, the system comprising
• a compressor having a low-pressure inlet and a high-pressure outlet,
• a condenser in fluid communication with both the low-pressure inlet and the high-pressure outlet of the compressor;
• an expansion device in fluid communication with the condenser, the expansion device having an inlet and an outlet;
• an evaporator in fluid communication with the outlet of the expansion device and the low-pressure inlet of the compressor;
• a reheat heat exchanger in fluid communication with the inlet of the expansion device, the low-pressure inlet of the compressor, and the high-pressure outlet of the compressor;
• a flow-control subsystem configured to control flow from the high-pressure outlet of the compressor to the condenser, from the high-pressure outlet of the compressor to the reheat heat exchanger, from the reheat heat exchanger to the low-pressure inlet of the compressor, and from the condenser to the low-pressure inlet of the compressor, the flow-control subsystem further configured to be switchable between at least a first state and a second state, wherein, in the first state, which is provided for cooling, the flow control subsystem substantially allows flow of refrigerant from the high-pressure outlet of the compressor to the condenser, substantially prevents flow of refrigerant from the high-pressure outlet of the compressor to the reheat heat exchanger, substantially allows flow of refrigerant from the reheat heat exchanger to the low-pressure inlet of the compressor to suction refrigerant present in the reheat heat exchanger, and substantially prevents flow of refrigerant from the condenser to the low-pressure inlet of the compressor, and wherein, in the second state, which is provided for humidity control, the flow control subsystem substantially prevents flow of refrigerant from the high-pressure outlet of the compressor to the condenser, substantially allows flow of refrigerant from the high-pressure outlet of the compressor to the reheat heat exchanger, substantially prevents flow of refrigerant from the reheat heat exchanger to the low-pressure inlet of the compressor, and substantially permits flow of refrigerant from the condenser to the low-pressure inlet of the compressor to suction refrigerant present in the condenser;
• providing refrigerant to the system;
• switching the flow control subsystem to the first state or to the second state, on the basis of whether cooling or dehumidification, respectively, is desired;
• and
• circulating the refrigerant.