Valve assembly for an air duct

Method for controlling air flow or air pressure in an air duct for ventilation of a building, comprising:

• placing a housing having an outer housing side adapted to be attached to said air duct and an inner housing side, opposite to the outer housing side, in said air duct;
• placing a valve in said housing, wherein the valve comprises a distal end and a proximal end, wherein said distal end is closer to the air duct than the proximal end and wherein said inner housing side of the housing is arranged to receive said valve;
• providing an electrical body within said housing, wherein the electrical body is adapted to connect a power source to an electrical device and wherein the electrical body comprises a distal end, a proximal end and an outer circumference at the distal end;
• characterized in that, the method comprises the additional step of regulating the flow or pressure of air flowing through the valve by rotating the electrical body around its longitudinal axis, thereby adjusting the size of the gap between the valve and the outer circumference at the distal end of the electrical body, wherein the size of the gap is measured perpendicular to the outer circumference at the distal end of the electrical body as the smallest distance from the distal end of the electrical body to the valve.