Each of the two EHL cabinet cabinets is a [http://www.silentium.com/?page_id=33 Silentium Accoustirack Active], a full-height acoustically-insulated rackmount cabinet with two fan units. The lower fan unit takes air from outside the cabinet and blows it up the front of the rackmount equipment area (cold zone). Air passes through the individual devices and is vented out the back of each unit into the hot zone. A second fan unit exhausts air from the hot zone out the top of the cabinet.