Heat pipes may be described as having two sections: pre-cool and reheat. The first section is located in the incoming air stream. When warm air passes over the heat pipes, the refrigerant vaporizes, carrying heat to the second section of heat pipes, placed downstream. Because some heat has been removed from the air before encountering, the evaporator coil, the incoming air stream section is called the pre-cool heat pipe.
Air passing through the evaporator coil is assisted to a lower temperature, resulting in greater condensate removal. The “overcooled” air is then reheated to a comfortable temperature by the reheat heat pipe section, using the heat transferred from the pre-cool heat pipe.