Wall of a house or similar structure, the wall comprising a hole and a device for extracting moisture from a wall or similar structure, the device being positioned in the hole, the device being configured to be positioned in a hole in said wall, the device comprising: - a front part which defines two openings which extend in different directions (18, 19), the openings being configured to act as an air intake and an air exit, - a chamber which defines an inner space, wherein an air flow channel for a main air flow extends through the inner space between the air intake and the air exit, - a housing which forms a housing wall of the chamber, the housing being connected to the front part, wherein the main air flow that flows through the air flow channel carries off moisture from the wall, characterised in that at a front section of the device a portion of the wall has been removed around the hole, resulting in a front outer hole having a larger diameter than the hole, wherein the front outer hole extends at a distance around or substantially around the front section of the housing and/or an intermediate part which interconnects the housing and the front part, the intermediate part being separate from the front part, the front outer hole forming a front outer channel which is in open communication with the outside and which acts as a second airflow channel, wherein the front outer channel is configured to remove moisture from a front part of the wall, wherein the air intake comprises a bifurcation zone where the incoming air flow bifurcates in the main air flow which flows through the air flow channel inside the housing and an outer air flow which flows through said front outer channel along the outside of the housing and wherein the air exit comprises a merge zone wherein the main air flow and the outer air flow merge. - a front part which defines two openings which extend in different directions (18, 19), the openings being configured to act as an air intake and an air exit, - a chamber which defines an inner space, wherein an air flow channel for a main air flow extends through the inner space between the air intake and the air exit, - a housing which forms a housing wall of the chamber, the housing being connected to the front part, wherein the main air flow that flows through the air flow channel carries off moisture from the wall, characterised in that at a front section of the device a portion of the wall has been removed around the hole, resulting in a front outer hole having a larger diameter than the hole, wherein the front outer hole extends at a distance around or substantially around the front section of the housing and/or an intermediate part which interconnects the housing and the front part, the intermediate part being separate from the front part, the front outer hole forming a front outer channel which is in open communication with the outside and which acts as a second airflow channel, wherein the front outer channel is configured to remove moisture from a front part of the wall, wherein the air intake comprises a bifurcation zone where the incoming air flow bifurcates in the main air flow which flows through the air flow channel inside the housing and an outer air flow which flows through said front outer channel along the outside of the housing and wherein the air exit comprises a merge zone wherein the main air flow and the outer air flow merge. wherein the main air flow that flows through the air flow channel carries off moisture from the wall, characterised in that at a front section of the device a portion of the wall has been removed around the hole, resulting in a front outer hole having a larger diameter than the hole, wherein the front outer hole extends at a distance around or substantially around the front section of the housing and/or an intermediate part which interconnects the housing and the front part, the intermediate part being separate from the front part, the front outer hole forming a front outer channel which is in open communication with the outside and which acts as a second airflow channel, wherein the front outer channel is configured to remove moisture from a front part of the wall, wherein the air intake comprises a bifurcation zone where the incoming air flow bifurcates in the main air flow which flows through the air flow channel inside the housing and an outer air flow which flows through said front outer channel along the outside of the housing and wherein the air exit comprises a merge zone wherein the main air flow and the outer air flow merge.