THE COR-A-VENT ® SYSTEM S-400 STRIP VENT COOLER OUTSIDE AIR COOLER OUTSIDE AIR VENTILATION CHUTE AIR FLOW INSULATION S-400 STRIP VENT VENTILATION CHUTE AIR FLOW INSULATION L O W E R E D A I R P R E S S U R E . . . . . . . . D R A W S A T T I C A I R O U T HOT MOIST AIR HOT MOIST AIR RELATIVEWIND CATHEDRAL CEILING ATTIC V-600E 11" RIDGE VENT Balanced Ventilation How It Works A balanced vent system is one that best utilizes three natural forces: air pressure, the thermal effect and diffusion. Basically, for every square inch of ridge (exhaust) vent you must balance it with at least one square inch or more of soffit (intake) vent. COR-A-VENT ® ridge & soffit vent products offer: • V-600 products – 20 sq. in. Net Free Vent Area (NFVA)/lineal foot • V-300 & Fold-A-Vent ® products – 13.5 sq. in. NFVA/lineal foot • S-400 Strip Vent line offers 10 sq. in. NFVA/lineal foot With a ridge and soffit system, cooler ventilation air will be drawn into the attic (or roof cavity if a cathedral ceiling) through the soffit/eave vents located within the positive pressure (intake) areas. It will exhaust through the vents in the negative pressure areas, at the ridge. Wind moving over the ridge literally “siphons” the hot/moist air out of attic. If the ridge vent were to be installed alone, then part of the ridge would become an inlet vent to relieve this “draw”. This could cause weather infiltration. The ridge vent must always be installed in combination with some form of soffit/eave intake vents. Do not use ridge vents with gable vents or other roof mounted vents. The “Ventilation Chute”, or air passageway between the soffit and the ridge must not be blocked or restricted so as to impede airflow. Once again, the ridge vent in this situation can act as intake and exhaust, causing weather infiltration. For a more attractive ridgeline, COR-A-VENT recommends installing the ridge vent to the very ends of any given ridge. A ridge that is the same height from end to end makes our vent even less noticeable. Please refer to the backside of this page for examples of typical continuous soffit vents and vent chute details.