Systemair array of weather-proof, high-performance louvres is made of quality materials to suit the requirements of different building types. They fit most external walling and screening applications. Available models designed as first-stage separation of airborne water, sand and dust, reducing the dust loading on ventilation filtration equipment. Selections with attractive compact yet simple design use ‘initial separation’ techniques in two stages to separate particles and return them to the face via a lower blade chute.