Abstract: A static electrical device assembly including: a static electrical device; a heat exchanger system including a first heat exchanger adapted for cooling of the static electrical device by transferring heat into ambient air, and a second heat exchanger adapted for recovering heat from the static electrical device; a flow passage adapted to provide a route for air flow between outdoor air and the first heat exchanger; a sensor system adapted to provide temperature information relating to the static electrical device; and a control system (CTRL) adapted to control the heat exchanger system based on information provided by the sensor system. The heat exchanger system further includes a shutter arrangement adapted to adjust a surface area of the flow passage, the control system (CTRL) is adapted to control the shutter arrangement between an open state and an enclosed state.