Abstract: A heat exchanger includes a plurality of heat exchange tubes stacked with a gap through which a first fluid can pass. The heat exchange tube includes: an internal flow path through which a second fluid for exchanging heat with the first fluid and which includes a folded portion; a plurality of slits provided between two flow path portions in the internal flow paths, the two flow path portions each extending from the folded portion and facing each other at an interval; and a plurality of protruding support portions in contact with another adjacent heat exchange tube to form the gap. As viewed in a stacking direction of the plurality of heat exchange tubes, at least one of the plurality of slits extends in a state where a center in an extending direction thereof deviates from a straight line connecting the two adjacent protruding support portions.

Abstract: A projector includes a light modulation device; a projection lens; a hermetic housing; a projector housing containing the hermetic housing; a heat exchanger; an air guide wall being located in the hermetic housing and partitioning the air guide passage from a main space containing the light modulation device, the air guide wall including: a communication part adjoining the heat exchanger and providing communication between the air guide passage and the main space, and an opening functioning as an inlet for guiding air from the main space into the air guide passage after the air has passed through the heat exchanger; and a fan located at the inlet so as to introduce the air in the main space into the air guide passage, to guide the air in the air guide passage to the communication part, and to blow the air from the communication part to the heat exchanger.

Abstract: A projector includes a light modulation device; a projection lens; a hermetic housing; a projector housing containing the hermetic housing; a heat exchanger; an air guide wall located in the hermetic housing and partitioning the air guide passage from the main space containing the light modulation device, the air guide wall including: a communication part adjoining the heat exchanger and providing communication between the air guide passage and the main space, and an opening functioning as the inlet for guiding air from the main space into the air guide passage after the air has passed through the heat exchanger; and a sirocco fan located at the inlet so as to introduce the air in the main space into the air guide passage, to guide the air in the air guide passage to the communication part, and to blow the air from the communication part to the heat exchanger.