This is based principally on good historical experience and simple psychrometric analysis handegord giroux 1984.
Build attic ventilation.
First determine your attic area by multiplying the length by the width.
The recommended ventilation ratio to provide for vented attic assemblies when an air barrier is present is the 1 300 ratio as specified by most building codes.
Measure the gable to decide how large a vent you can.
Power gable vent shutter is designed to be used with master flow egv pg series electric gable fans.
Power gable vent shutter is automatic 20 in.
You can also contact your local municipality to check on building code in your area.
Although you can buy manufactured gable vents you might want to build your own wooden vent that matches your home or building s exterior.
Attic ventilation serves two main functions.
Attic for example has an area of 1 200 sq.
A 30 x 40 ft.
Building codes vary.
Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca.
In of vent opening per 150 sq.
Most building codes require a ratio of 1 150 ventilation space to attic floor space.
However if your attic has blocked soffit vents and is not well sealed from the rest of the house attic fans will suck cool conditioned air up out of the house and into the attic.
Cool your home lower energy costs and increase efficiency with an attic ventilation fan.
Then aim for about 1 sq.
The building code lets you reduce that by half under some conditions but more roof ventilation is usually better.
In order to facilitate this exchange of warm and cool air the general rule of thumb suggests installing at least 1 sq.
If your attic isn t ventilated well that humid moist air will build up in the attic space and can cause mold to grow.
This article will cover why you need ventilation the most common type of ventilation the building code requirements and common ventilation related issues.
The shutter will open when the electric gable vent is operating.
This article will show you how it can be done.
To better understand attic ventilation it is best to start with the basics.
Therefore whole house fans are best suited for open well vented attics.
Of vent for every 300 sq.