Attic Intake Ventilation Calculation

It s important there is a balance between the intake and exhaust ventilation to help ensure air flows smoothly and efficiently.

Attic intake ventilation calculation.

One of the easiest and most effective ways of ventilation on a roof is to use a ridge vent. For balanced ventilation an equal amount of intake vent area net free area should also be installed. Let owens corning roofing help you calculate exactly how much ventilation you will need for a healthy and balanced attic with our 4 step ventilation calculator. 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.

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. And in many of these cases the hip roof forms a large volumetric attic space to ventilate. However with only two 1 ft x 2 ft gable roof vents i ll need an additional 7 sq ft of exhaust vents. In order to create a consistent flow of cool dry air through your attic you need to make sure the air has a way to come in and go out.

Figure 7 mechanical ventilation used with a hip roof. Now you know how many square inches of attic roof venting you need for the roof and soffit. This calculator gives you the required attic ventilation requirement. One method is to use a powered attic vent with a humidistat thermostat located close to the ridge or top of the roof.

Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. By gaf roof views. Use this calculator to help determine the proper amount of attic ventilation based on u s. Use avp s roof vent calculator to determine the number and size of exhaust vents you will need.

I need additional exhaust ventilation in my roof with the planned installation of a whole house fan in the attic of my home located in sf bay area. Enter square footage calculate or enter the square footage of the attic or area to be vented. Of course there should be intake vents to ensure a balanced system. 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.

You mention exhaust vents shouldn t exceed intake vents in the roof for proper circulation. Intake vents located at the lowest part of the roof under the eaves allow cool.