The units are comprised of a proprietary desiccant wheel positioned between the coils of a refrigeration circuit. Return air (or a blend of OA with RA) from the space flows across a condensing coil where it is heated.

The warmer air is then used to remove moisture from the desiccant wheel which increases the moisture content of the air prior to the evaporator coil. The evaporator coil wrings out moisture and the saturated air leaving the evaporator is then further dehumidified by the desiccant wheel. The ability of the desiccant wheel to move moisture around the evaporator coil allows the evaporator to operate at a higher temperature and the condenser at lower temperatures resulting in below freezing dew points at a very high COP.

As an option a second condenser may be used to reject heat outside the space. Additional optons include exhaust air energy recovery, controlled outdoor air mixing for ventilation and pressurization, post-heating, post-cooling and upgraded filtration packages.

Expensive gas fired desiccant units have traditionally been used to dehumidify ice rinks and other cold environments. Operating costs are high, the units are complicated to operate, and maintenance and first costsare high.

These new cold environment dehumidfiers can achieve comparable dew point performance with far less energy consumption. Simplicity of operation and low maintenance requirements differentiate it further from the gas fired type desiccant units.