Attic Air Ventilation Requirements

You can calculate attic ventilation requirements by determining the square footage of your attic floor its width times its length and compare that to the total required net free area nfa.

Attic air ventilation requirements.

The following product options will allow you to achieve an intake nfva of 528 square inches. Prior to installing the ridge vent a 1 inch wide strip of roof decking is cut out along both sides of the ridgeline to allow for air movement through the vent. Attic ventilation is an important part of keeping your building healthy. Vents are rated by their net free area or the amount of space for air to flow in or out.

The building code lets you reduce that by half under some conditions but more roof ventilation is usually better. 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. 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. This means that if you have a 1500 sq attic then you would need at least 10 sf of ventilation.

Lowering the temperature in the attic can help reduce air. To lower attic temperatures and to remove excess moisture. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. 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.

Intake vents located at the lowest part of the roof under the eaves allow cool. This article will cover why you need ventilation the most common type of ventilation the building code requirements and common ventilation related issues. Choose one of the following products to meet the recommended intake nfva of 528 square inches. If not measure the size yourself.

Attic ventilation requirements air circulation. So how much of that air circulating through your attic you really need you can find online calculators to give you the explanation in numbers and i ll try to add a few words to it. The open area of a vent is sometimes listed on the roof air vent as nfva net free vent area. Then aim for about 1 sq.

In of vent opening per 150 sq. A ridge vent is a ventilation strip that is placed along the ridgeline of the home. Current regulations state that the minimum attic ventilation requirements are 150 1. Attic fans are intended to cool hot attics by drawing in cooler outside air from attic vents soffit and gable and pushing hot air to the outside.