Patent-family-91484437

An intermediate ventilation valve (200) adapted to control airflow between a ventilation window (2) and an air heat treatment unit (4), the intermediate ventilation valve (200) comprises - a valve body (210) having an internal cavity (211), the internal cavity (211) comprises an outside-facing opening (214) facing outside atmosphere, an inside-facing opening (218) facing an inside of a building, a bottom-facing opening (216) configured to be connected to an air heat treatment unit (4) and top-facing opening (212) configured to be connected to a ventilation window (2); - a third block unit (240) comprising a third flap (242) configured to substantially block air-flow through the outside-facing opening (214) and the bottom-facing opening (216), the third flap (242) being rotatable within the internal (211) cavity between an upper position (248), where the third flap (242) substantially blocks the outside-facing opening (214), to an intermediate position (246), where the third flap (242) substantially blocks airflow from the out- side-facing opening (214) to the inside facing opening (218), and further rotatable to a lower position (244), where the third flap (242) substantially blocks the bottom-facing opening (); - a fourth block unit (250) comprising a fourth flap (252) configured to substantially block airflow through the inside-facing opening (218), the fourth flap (252) being rotatable between a lower position (254), where the inside-facing opening (218) is blocked, and an upper position (258), where airflow is enabled through the inside-facing opening (218).