Balanced Attic Ventilation

An under roof cathedral ceiling or attic ventilation system to help the building in any way needs to be properly designed and installed with adequate intake venting at the eaves outlet venting at the ridge and with careful sealing of air leaks from the occupied space into the attic or roof cavity to avoid heat losses or increases in both moisture movement into the roof cavity and increased heating or cooling costs.

Balanced attic ventilation.

This method relies on convection which is a mode of heat transfer that is caused by the tendency of warmer air to rise. Generally speaking you need a ratio of 1 300 where for every 300 square feet of ceiling space you need 1 square foot of attic ventilation. The balanced approach helps to optimize air exchange between the attic and the outdoors and allows for effective management of temperature and moisture inside the attic. That said air resistance and interference such as vent grates reduces the area of true ventilation.

Intake vents located at the lowest part of the roof under the eaves allow cool. Proper attic ventilation can help reduce the load on your air conditioner. The unbalanced attic consisted of a mix of ridge vents and electric power fans without intake ventilation. Figure 1 a balanced system.

They have two basic models. Help protect your roof system from premature deterioration by installing a properly balanced attic ventilation system consisting of cobra exhaust vent at the ridge and adequate intake ventilation at or near the soffit areas of your roof. In other words the entire vent opening doesn t count as vented space. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.

Figure courtesy of the nrca. There are two methods used to ventilate attics. 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. The balanced attic consisted of electric power fans repositioned for maximum efficiency and air vent s new edge vent a shingle over intake vent.

I m thinking of the qufresh fan made by air king. To calculate the amount of ventilation you need for your home visit gaf s ventilation calculator now. The most common method is the static method. Another way to get balanced ventilation is to use the exhaust fans with controls and also install a supply fan.

Calculate or enter the square footage of the attic or area to be vented.