Ratio Of Soffit Vents To Roof Vents

Determine the amount of intake venting required.

Ratio of soffit vents to roof vents.

In nfva per lineal foot. A serious error is a roof outlet vent net free area that exceeds the air inlets at lower roof edges or eaves. Rafter vents or insulation baffles install in any rafter space to create narrow gaps that direct fresh air from the soffit vents to the peak of the roof. As a homeowner it is important that you review the soffit areas of the home for soffit vents.

Roof vents choose one of the following products to meet the recommended exhaust nfva of 528 square inches. Resin circular mini wall louver soffit vent in white 6 pack model rlsc2 view the master flow intake vents 9 28 9 28. Where eave or cornice vents note. And for roofs 11 12 pitch and higher add 30 more cfm to handle the larger volume of attic space.

Ventsure 4 foot strip heat moisture ridge vent. These specialty vents do not affect the. One square foot equals 144 square inches so the standard 16 inch by 8 inch soffit vent is 0 89 square feet. For the number of soffit vents in the example divide 8 square feet of ventilation needed by 0 5 for the number of rectangular vents required 16 in the example.

P er lineal foot 1 2of 20 in each overhang. Master flow 2 in. For example our v 600 products have 20 sq. Master flow 15 amerimax home products 1 deflect o 1 gibraltar building products 1 mounting position.

Divide this by 144 to calculate how many square feet each vent is. For example if you use 16 inch by 8 inch soffit vents each vent is 128 square inches. An equal or greater amount of vent opening sq. Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation evenly split between intake and exhaust for every 300 square feet of attic floor space.

Choosing round soffit vents for. The ratio of soffit intake to roof outlet should be at least 2 1 to avoid unnecessary these heat losses from the building. To balance this you need 2 soffit eave intake vents of approximately 10 sq. But the ratio of intake air to outlet air is of critical importance too.

Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge. An important part of installing any system of ventilation into your roof system is to make sure that there is a point of entry and a point of exit for airflow.