We have a smoking room thats supplied and extracted by one system along with all the other spaces (no return). We are providing more extract than supply in the smoking room, and in the adjacent area we are providing more supply than extract. The total supply and extract between the other space and the smoking room is the same, and my question is how to handle the transfer air?
I expect we need a transfer grille with some sort of pressure dependent backdraft damper. So if the pressure in the room drops below, say 50Pa, the backdraft damper closes, but once the pressure in the room returns to 50Pa it would begin to open to allow air from the non-smoking-area, into the smoking area.
Anyone have experience with this?