Methods and apparatus that improve the effectiveness of a compression-based refrigeration cycle dehumidifier by allocating thermally distinct sections of the condenser to different air flows are disclosed. A bypass opening and divider plate direct ambient air to the refrigerant inlet section of the condenser. Air that has been cooled and dehumidified by the evaporator is directed to the rest of the condenser, with the air from the refrigerant outlet section of the evaporator being preferentially directed downstream, in the refrigerant flow path sense, from that section of the condenser already allocated to the ambient air coming from the bypass opening. The flows of ambient air and dehumidified air can be adjusted to improve moisture removal rates and avoid blockage of the evaporator by freezing of the condensate onto the evaporator. The system may also be used to remove condensates other than water.