An air heater is intended to be used in combination with an air cleaner comprising an air cleaner case, an air cleaner element dividing a space defined by the air cleaner case into a dust chamber on an upstream side with respect to the flowing direction of intake air and a clean chamber on a downstream side with respect to the flowing direction of intake air, and an intake duct connecting an air outlet pipe connected to the clean chamber to a throttle valve. The air heater comprises a heat exchanger case covering an opening formed in the air cleaner case so as to open into the dust chamber, and forming a heating passage for heating intake air; a heat exchanger; through which cooling water is circulated, disposed in the intake air passage defined by the heat exchanger case; a passage selector plate for selectively opening either the heating passage passing the heat exchanger or a bypass passage bypassing the heat exchanger and directly connected to the dust chamber; and a thermosensitive driving means provided with a temperature sensor for sensing intake air temperature and capable of controlling the passage selector plate. The thermosensitive driving means controls the passage selector plate automatically according to the temperature of intake air to heat intake air only when necessary.
Air cleaner including a case having an inlet and an outlet, a fan inside of the case, for drawing air through the inlet and discharging the air through the outlet, a filter assembly inside of the case for cleaning the air drawn into the case through the inlet, a heat exchanger inside of the case for heating or cooling the air drawn into the case, selectively, and a plurality of fins between the fan and the outlet for guiding the air drawn into the case to the outlet, thereby ventilating the room.
