Gas valve for ventilation, a circuit for a ventilation system and a method for determining a releasing gas flow

A method for determining a released gas flow of a pressure release valve comprising a first gas chamber formed by a first duct and a second duct, a second gas chamber, and a membrane disposed between the first gas chamber and the second gas chamber, the method comprising:

• pressurizing the membrane to temporarily seal the first gas chamber from the second gas chamber;
• supplying an inhalation gas to the first gas chamber in a first direction in through the first duct and out through the second duct;
• supplying an exhalation gas to the first gas chamber in a second direction in through the second duct and out through the first duct;
• depressurizing the membrane to temporarily unseal the first gas chamber from the second gas chamber;
• measuring a gas pressure of the exhalation gas in the second gas chamber;
• and
• determining the released gas flow based on the measured gas pressure in the second gas chamber.