Vent in a floor, the vent is designed to remove waste gases from a heating system and consists of a grill cut into a timber floor. (15cm x 15cm in size) The floor the vent is fixed into is suspended above ground and is exposed so that wind and other external factors can have an affect on how much air is drawn through the vent in certain weather conditions. ie strong winds draw out more air from the internal structure. My question is this, what measures could be taken to reduce air loss through the floor vent in high wind conditions without covering the vent or hindering safe removal of waste gas? Thank you gentlemen.