Air dehumidifier

An air handling unit for an HVACR system, comprising:

• an air dehumidifying (AD) flow path and an air regeneration (AR) flow path separate from the AD flow path;
• a first desiccant wheel disposed in each of the AD flow path and the AR flow path, the first desiccant wheel configured to dehumidify air in the AD flow path;
• a second desiccant wheel disposed in each of the AD flow path and the AR flow path, the second desiccant wheel configured to further dehumidify the air in the AD flow path;
• a first cooler heat exchanger disposed in the AD flow path upstream of the first desiccant wheel and the second desiccant wheel, the first cooler heat exchanger configured to cool the air in the AD flow path with a chiller liquid supplied from a chiller system at a temperature of at or above 50° F.;
• a second cooler heat exchanger disposed in the AD flow path between the first desiccant wheel and the second desiccant wheel, the second cooler heat exchanger configured to cool the air with the chiller liquid supplied from the chiller system;
• and
• a heater disposed in the AR flow path upstream of the first desiccant wheel and the second desiccant wheel.

A method of conditioning air in an HVACR system, comprising:

• directing air through an air dehumidifying (AD) flow path of an air handling unit, which includes:
• cooling, via a first cooler heat exchanger, the air with a chiller liquid supplied from a chiller system at a temperature of at or above 50° F.,
• dehumidifying, via a first end of a first desiccant wheel, the air cooled by the first cooler heat exchanger using a first desiccant of the first desiccant wheel,
• cooling, via a second cooler heat exchanger, the air dehumidified by the first desiccant wheel with the chiller liquid, and
• dehumidifying, with a first end of a second desiccant wheel, the air cooled by the second cooler heat exchanger using a second desiccant of the second desiccant wheel;
• and
• directing air through an air regeneration (AR) flow path of the air handling unit to regenerate the first desiccant and the second desiccant, which includes:
• passing the air in the AR flow path through a second end of the first desiccant wheel and through a second end of the second desiccant wheel, and
• heating, via a heater, the air in the AR flow path prior to being passed through the second end of the first desiccant wheel and through the second end of the second desiccant wheel.