See figure 2.
Attic fan intake air.
Similar to the static method adequate amounts of intake air into the attic space should be provided.
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.
Negative pressure can cause air conditioned air to be pulled from your home or create a vacuum in the attic that will burn out a fan our technician will assess your current intake air to determine if any additional venting is required.
A minimum of 70 linear feet or 700 sq in.
According to the national roofing contractors association nrca a power vent with an airflow rate of 1 0 cubic foot per minute per square foot of attic space measured at the attic floor is generally considered to be equivalent.
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.
Not having enough intake air could lead to negative pressure.
Intake vents located at the lowest part of the roof under the eaves allow cool air to enter the attic.
Hot air exhaust vents located at the peak of the roof allow hot air to escape.