A dehumidifier includes an air flow path with first, second and third segments in series from upstream to downstream and passing ambient air respectively to an evaporator coil then to a condenser coil and then discharging same. The air flow path has a fourth segment passing ambient air to the condenser coil in parallel with the noted second air flow path segment. A bypass door is configured to selectively block air flow along the fourth segment and allow air flow along the fourth segment.