Attic Intake Ventilation Calculation

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.

Attic intake ventilation calculation.

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. 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. One method is to use a powered attic vent with a humidistat thermostat located close to the ridge or top of the roof.

You mention exhaust vents shouldn t exceed intake vents in the roof for proper circulation. Of course there should be intake vents to ensure a balanced system. 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. Use this calculator to help determine the proper amount of attic ventilation based on u s.

For balanced ventilation an equal amount of intake vent area net free area should also be installed. Now you know how many square inches of attic roof venting you need for the roof and soffit. 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. One of the easiest and most effective ways of ventilation on a roof is to use a ridge vent.

This calculator gives you the required attic ventilation requirement. Enter square footage calculate or enter the square footage of the attic or area to be vented. By gaf roof views. Figure 7 mechanical ventilation used with a hip roof.

It s important there is a balance between the intake and exhaust ventilation to help ensure air flows smoothly and efficiently. Use avp s roof vent calculator to determine the number and size of exhaust vents you will need. The first step is to check out this 60 second video and learn about the 300 1 rule the difference between intake and exhaust ventilation and why proper ventilation is so important to get right to help calculate your attic ventilation needs visit gaf ventilation calculator. Intake vents located at the lowest part of the roof under the eaves allow cool.

Next divide that number by 2. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.