A dehumidifying system and method for reducing humidity in ambient air is disclosed. The system includes a circulation unit, a refrigeration unit, a condensate receptacle for receiving condensate generated by the refrigeration unit, a controller to control both the circulation and refrigeration units, and wherein the controller receives input from one or more ambient sensors configured to sense ambient conditions, and a user interface configured to receive input from a user. The system implements variable speed control within the circulation and/or refrigeration unit to maximize efficiency or capacity under a current threshold, and enables the system to delay the need for defrost cycling during low temperature operation.