Systems and methods for air dehumidification in an enclosed space

A method of using a dehumidification system to dehumidify an enclosed space, the method comprising:

• supplying supply air to the enclosed space through a supply air outlet of a supply plenum having a return air inlet;
• directing outdoor air through an outdoor air inlet of a scavenger plenum having an exhaust outlet;
• selectively directing return air through a desiccant dehumidifier arranged inside the supply plenum to remove water from the return air using a desiccant;
• selectively directing the outdoor air through a desiccant regenerator arranged inside the scavenger plenum to remove water from the desiccant using the outdoor air;
• directing the outdoor air through a first portion of a heat recovery system arranged in the scavenger plenum upstream of the desiccant regenerator, the first portion of the heat recovery system configured to reject heat to air flowing therethrough;
• selectively directing one or both of the outdoor air and the return air through a second portion of the heat recovery system arranged in the scavenger plenum downstream of the desiccant regenerator, the second portion of the heat recovery system configured to absorb heat from air flowing therethrough;
• operating the dehumidification system in a plurality of modes based on outdoor air conditions and a setpoint for air in the enclosed space, the plurality of modes comprising;
• a wet mode in which the desiccant dehumidifier and the desiccant regenerator are operational, a dehumidifier damper arranged in the supply plenum upstream of the desiccant dehumidifier and a regenerator damper arranged in the scavenger plenum upstream of the desiccant regenerator are fully open, and a first redirection damper connecting the supply plenum to the scavenger plenum upstream of the desiccant dehumidifier and downstream of the desiccant regenerator and a second redirection damper connecting the supply plenum to the scavenger plenum downstream of the desiccant dehumidifier and upstream of the desiccant regenerator are fully closed;
• a dry mode in which the desiccant dehumidifier and the desiccant regenerator are off, the dehumidifier damper and the regenerator damper are fully closed, and the first and second redirection dampers are fully open;
• and
• a blended mode in which the desiccant dehumidifier and the desiccant regenerator are operational, the dehumidifier damper and the regenerator damper are partially open, and the first and second redirection dampers are partially open.