The present invention describes a method and apparatus for conditioning air utilizing a desiccant based air conditioning system requiring substantially less regeneration energy than typical systems. This regeneration energy reduction is accomplished through the use of two separate desiccant devices and an indirect evaporative cooler having both a wet and dry side for air flow-through. The first desiccant device regeneration air is first passed through the wet side of the indirect evaporative cooler wherein it is humidified and heated. This air is then dehumidified by passing through the second desiccant device which operated at a high moisture content. This results in a substantial amount of moisture being adsorbed from the first regeneration air stream causing a substantial air temperature increase and thereby, reducing the auxiliary heat required. The second desiccant device may be regenerated with ambient air.
