HEAT EXCHANGE VENTILATOR

A heat exchange ventilator (10) includes: a housing (1) including a supply air path and an exhaust air path independent of the supply air path; a supply air blower (11) that is installed in a supply air path and generates a supply air flow in the supply air path; an exhaust air blower (12) that is installed in the exhaust air path and generates an exhaust air flow in the exhaust air path; a heat exchanger (2) that causes the supply air path and the exhaust air path to cross each other and causes heat exchange between the supply air flow and the exhaust air flow; a supply-air-side drain pan (20a) installed downstream of the heat exchanger (2) in the supply air path; and an exhaust-air-side drain pan (20b) installed downstream of the heat exchanger (2) in the exhaust air path. Each of the supply-air-side drain pan (20a) and the exhaust-air-side drain pan (20b) includes a backflow prevention valve (22), and a supply-air-side drain discharge port (21a) or an exhaust-air-side drain discharge port (21b) for discharge of dew condensation water generated in the housing (1) to outside.