Patent ID: 7013950

Claim:
A ventilation device for ventilation of a room comprising: a device casing, which is provided in or adjacent to an outer wall of said room and which connects room air to outside air; a counter flow heat-exchanger, provided in the casing and transferring heat between outgoing and ingoing airflows, respectively; two fans arranged in said casing, of which one is connected to an ingoing air duct of the heat-exchanger and the other to an outgoing air duct of the heat-exchanger; a sensor arranged to detect airflows in said outgoing air duct and said ingoing air duct and emit signals proportional to said airflows; a control means, which, depending on the values given by the sensor, is arranged to regulate rotation speeds of the fans according to said proportional signals, wherein: the sensor comprises first sensing means arranged in the ingoing air duct and second sensing means arranged in the outgoing air duct; and said first and second sensing means are connected to each other and arranged to be affected by the difference in airflow in the two ducts by deviating from a neutral position, to thereby emit said signals proportional to the difference in airflow to the control means for controlling the rotation speeds of the fans, wherein said sensing means are connected to each other through a shaft; and said sensor comprises a device for monitoring the position of said sensing means and transmitting signals to said control means.