How Many Roof Vents Required

Ventsure 4 foot strip heat moisture ridge vent.

How many roof vents required.

A roof vent is a type of fixture installed on your roof that exhausts hot air. 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. Foot of ventilation for every 150 sq. This calculator gives you the required attic ventilation requirement.

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. Taking advantage of this natural process referred to as passive ventilation is the most common way to vent an attic. Now you know how many square inches of attic roof venting you need for the roof and soffit. 27 lineal feet required.

Figure 7 mechanical ventilation used with a hip roof. Advantages of proper roofing ventilation. Of net free area of intake needed at or near the soffit. Next divide that number by 2.

Of course there should be intake vents to ensure a balanced system. Proper attic ventilation offers numerous advantages to the homeowner. And in many of these cases the hip roof forms a large volumetric attic space to ventilate. Ridge static attic vents 384 00 minimum sq.

One of the easiest and most. In our case the required 4 vents for the 1200 sq ft house multiply the 144 cubic inches by 4 576 cubic inches. One method is to use a powered attic vent with a humidistat thermostat located close to the ridge or top of the roof. Luckily there is a basic formula you can use to determine this.

The size of your roof and attic space will determine how many roof vents you need. 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. For the 1 150 attic ventilation requirement simply double the amount of exhaust and intake calculated. Although there are many different types of roof vents to choose from ensuring you have the right number of both intake and exhaust vents is a central part of roof design.

Hot air exhaust vents located at the peak of the roof allow hot air to escape. Feet of attic space divided 50 50.