This standard applies to desiccant-based dehumidifiers operating at atmospheric pressure. The dehumidifier shall use solid or liquid desiccants that are regenerated using heat energy. 2.2 Normally@ equipment within this standard would consist of one or more desiccant contact stations through which the air to be dehumidified is moved@ a means to expose the moistureladen desiccant to a source of heat energy for regeneration@ and a heating device. Ancillary devices are normally used to move air to be dehumidified through the device and to provide ventilation for regeneration@ but they are not a part of this standard. This standard is intended to a. describe a uniform method of testing for obtaining performance data@ b. reference and specify test instruments and apparatus@ c. describe and specify test data to be recorded@ and d. describe and specify calculations to be made from the test data. This standard does not apply to a. dehumidifiers operating at other than atmospheric pressure@ b. dehumidifiers not using a desiccant for dehumidification@ c. dehumidifiers not using heat for regeneration of the desiccant@ d. ancillary equipment that may be used in any dehumidification process@ such as fans or pre- or post-conditioning equipment@ or e. dehumidifiers using a sealing arrangement that results in leakage rates in excess of 1% of process flow PURPOSE The purpose of this standard is to provide test methods for determining the moisture removal capacity of heat-regenerated desiccant dehumidifiers@ as well as the coincident thermal energy performance@ so that comparative evaluations of capacity and performance can be made irrespective of the type or make of the device.