The BlueComfort Classic system integrates an air conditioner and water heater into a single system. BlueComfort Classic units are equipped with a second heat exchanger connected to a diesel heater. In cooling mode, the heater is turned off so that only the air conditioning circuit is running. The water heater operates in heating mode. The heat exchanger, and therefore the air streaming through it, is heated. In “dehumidification” mode, the air is first cooled and then reheated and therefore dehumidified.