Abstract: A method and apparatus for conditioning air for an enclosure is disclosed in which a stream of outside ambient air is dried in a desiccant core and cooled; thereafter the air stream is further cooled by passing the same over a cooling element whose surface temperature under normal operating conditions is higher than the dew point of the cooled and dried air leaving the heat exchanger. The thus cooled outside air stream is supplied to the enclosure while return air is withdrawn from the enclosure and supplied to desiccant core to pass in heat and moisture exchange relation to the outside air stream in order to remove moisture sorbed by the desiccant material from the outside air stream.

Abstract: A method and apparatus for conditioning air for an enclosure is disclosed in which a first stream of outside ambient air is dried in a desiccant wheel dehumidifier and cooled in a heat exchanger while maintaining the moisture content thereof relatively unchanged; thereafter the air stream is cooled by passing the same over a cooling element whose surface temperature under normal operating conditions is higher than the dew point of the cooled and dried air leaving the heat exchanger. The thus cooled first outside air stream is then supplied to the enclosure while return air is withdrawn from the enclosure and supplied to the heat exchanger to pass in heat exchange relation to the dried first outside air stream in order to reduce the temperature of the first outside air stream in the heat exchanger while increasing the temperature of the enclosure return air which can be either exhausted to the atmosphere or used to reactivate the desiccant wheel before being returned to the atmosphere.