An air treatment apparatus (10), such as a dehumidifier or latent cooling system, has a desiccant wheel (12) having a plurality of similar internal structures (14), a shroud (16), at least a first fan (18, 20), a motor (30), an axle (32), slip rings (34), and sliding contacts (36). The similar internal structures are coated with a desiccant, and may be shaped as blades, cylinders, boxes, teeth, or corrugations. The shroud divides the wheel into an active area where the desiccant removes moisture to provide treated air (22), and a regeneration area where the desiccant is heated to release the adsorbed moisture from the air (28). Switches, such as magnetic switches, apply electrical power to heaters in the similar internal structures as they rotate into the regeneration area thereby heating and drying the desiccant.

The AHU includes an air dehumidifying (AD) flow path, an air regeneration (AR) flow path, a first desiccant wheel and a second desiccant wheel each in the AD flow path and the AR flow path, a first cooler heat exchanger in the AD flow path, a second cooler in the AD flow path, and a heater disposed in the AR flow path. An HVACR system includes the AHU and a chiller configured to supply chiller liquid to the first cooler heat exchanger and the second cooler heat exchanger in the AHU. A method of conditioning air in an HVACR system includes directing air through the air dehumidifying (AD) flow path and directing air through an air regeneration (AR) flow path to regenerate the desiccant in a first desiccant wheel and the desiccant in a second desiccant wheel.

An air treatment apparatus (10), such as a dehumidifier or latent cooling system, has a desiccant wheel (12) having a plurality of similar internal structures (14), a shroud (16), at least a first fan (18, 20), a motor (30), an axle (32), slip rings (34), and sliding contacts (36). The similar internal structures are coated with a desiccant, and may be shaped as blades, cylinders, boxes, teeth, or corrugations. The shroud divides the wheel into an active area where the desiccant removes moisture to provide treated air (22), and a regeneration area where the desiccant is heated to release the adsorbed moisture from the air (28). Switches, such as magnetic switches, apply electrical power to heaters in the similar internal structures as they rotate into the regeneration area thereby heating and drying the desiccant.