An efficient way of installing outdoor air inlets and exhaust air outlets is to lead them both to an outside wall combi hood fitted to the outer wall. The duct inlet and outlet can be located at the same point on the building, which often simplifies duct installation.
Cool outdoor air is drawn in at the bottom of the outside wall combi hood and exhaust air, a little warmer, is blown out through a grating on the front of the hood. The velocity of the warmer exhaust air is higher and it therefore rises on exiting the hood.
Thus that the two air paths do not cross and there is no risk of the exhaust air being drawn back into the building.
All outside wall combi hoods are, as standard, powder coated in white but can be ordered in any colour, allowing the outside wall combi hood to harmonize with the building.