Dehumidification unit and desiccant drum therein

A heating, ventilation, air conditioning, and refrigeration (HVACR) system comprising:

• a refrigeration circuit configured to cool a working fluid that includes refrigerant;
• and
• a dehumidifying air handling unit including:
• a housing including an air inlet and an air outlet, a main airflow path extending through the housing from the air inlet to the air outlet,
• a hollow desiccant drum disposed in the main airflow path and configured to rotate within the housing, the hollow desiccant drum including an interior space, a sidewall that surrounds the interior space, channels that extend through the sidewall, and a desiccant provided in the channels, and
• a heat exchanger disposed in the interior space of the desiccant drum, the heat exchanger configured to cool air flowing through the interior space of the hollow desiccant drum, wherein the heat exchanger uses the working fluid or an intermediate fluid cooled by the working fluid to cool the air.

A method of conditioning air in a dehumidifying air handling unit, the dehumidifying air handling unit including a housing, a hollow desiccant drum disposed within the housing, and a heat exchanger disposed in an interior space of the desiccant drum, the method comprising:

• rotating the hollow desiccant drum relative to the housing, the hollow desiccant drum including the interior space, a sidewall that surrounds the interior space, channels that extend through the sidewall, and a desiccant provided in the channels,
• directing the air to pass through the hollow desiccant drum, which includes:
• directing the air into the interior space of the hollow desiccant drum by passing the air through a first set of the channels in the sidewall in contact with the desiccant,
• cooling, with the heat exchanger, the air in the interior space of the hollow desiccant drum, and
• adsorbing, with the desiccant, moisture from the air cooled by the heat exchanger by passing the air cooled by the heat exchanger out of the hollow desiccant drum through a second set of the channels in the sidewall in contact with the desiccant.