a ventilation unit for a vehicle seat has an air distribution layer that is at least on one side and is covered by a cover layer . a fan unit is held by a two - part adapter element — a first adapter part and a second adapter part — and has a flow connection to the air distribution layer via this adapter element . the first adapter part has a flange plate that is located between the air distribution layer and the cover layer and connection elements that extend starting at the flange plate through the cover layer and that connect to the second adapter part of the adapter element to which the fan unit is attached . the side of the cover layer that points away from the air distribution layer defines a positioning plane that receives a seat frame spring structure , which is delimited by parts of the second adapter part on the side that is opposite to the cover layer .