Introduction
1
DryCool HD Operator and Maintenance Manual
P00960167-1
1. Introduction
This manual includes installation, operation, and troubleshooting instructions for the DryCool™ HD desiccant
dehumidifier. The unit provides significant drying capability in a small package and utilizes a refrigerant circuit
in conjunction with a heat reactivated desiccant wheel to provide an efficient drying capability. Due to the
substantial capabilities of the desiccant wheel, the unit can continue to provide low supply dew point conditions.
The hybrid desiccant refrigeration cycle provides the most efficient small dehumidifier available. In addition,
the supply air is discharged at approximately space neutral temperature so that it does not add additional cooling
load to the space.
1.1. Technical Description
The DryCool™ HD uses a refrigeration system similar to an air conditioner to remove heat and moisture from
the incoming air. In addition a HoneyCombe® desiccant wheel downstream of the evaporator coil removes
further moisture from the airstream in a vapor state.
The HoneyCombe® desiccant wheel is operated with two separate air streams. The supply air stream is pulled
from the conditioned space and in controlled amounts from outside. The reactivation air stream is generally
taken entirely from outside. See
Figure 1
below.
Figure 1: DryCool™ HD Operating Principle
Within the closed circuit refrigeration system hot - high pressure refrigerant gas is routed from the compressor
to the condenser coil. Here the refrigerant is cooled and condensed by giving up its heat to the passing air. This
heated air is used to reactivate the HoneyCombe® desiccant wheel. The heat applied to the wheel allows
moisture to be driven off and discharged by the reactivation fan. Thus the reactivation air needs to be ducted to
the outside.
The refrigerant liquid then passes through a filter - drier and capillary tubing which causes the refrigerant
pressure and temperature to drop. It next enters the evaporator coil where the refrigerant absorbs heat from the
incoming air. The compressor then draws the cool refrigerant gas and compresses it to a high pressure and
temperature to repeat the process.
