Humidity control unit and method

A method for conditioning ambient air for supply to a space, the method comprising the steps of:

• cooling, in a first passage, a first ambient supply airstream with a cooling coil of a refrigerant system, then selectively passing the cooled ambient supply airstream through a segment of a rotating desiccant wheel to further reduce the moisture content of the first ambient airstream, and passing the thus treated air to the space;
• heating, in a second passage, a second ambient airstream with a condensing coil of the refrigerant system and selectively passing the heated second ambient airstream through a regeneration segment of the desiccant wheel to regenerate the desiccant wheel;
• bypassing a portion of the first ambient supply airstream around the cooling coil in the first passage and into the space as an ambient bypass airstream;
• and
• selectively heating the ambient bypass airstream before reaching the space.

An air conditioning and dehumidification system comprising:

• a first passage through which a first ambient supply airstream flows and exits as supply air to a space;
• a second passage through which a second ambient supply airstream flows;
• a refrigeration circuit including an evaporator coil in the first passage and a condenser coil in the second passage;
• a desiccant wheel rotating in a plane perpendicular to the first and second passages, the desiccant wheel being divided into plural segments including a first segment functioning as a process segment and located in the first passage and a second segment functioning as a regeneration segment and located in the second passage;
• and
• an ambient air bypass defining a third passage through which bypass ambient air passes, the bypass ambient air bypassing the evaporator coil and the first segment of the desiccant wheel before entering the space,
• wherein the bypass ambient air is selectively heated in the third passage before entering the space as a bypass airstream.