Effective attic ventilation systems also promote energy efficiency by helping reduce the load on your air conditioner in the summer.
Attic ventilation recommendations range from 1 square foot of ventilation for every 150 square feet of attic space to 1 square foot for every 300 square feet. According to the NRCA, a common way to vent asphalt roofs is with non-powered or “passive” ventilation that balances air intake with air exhaust. Common vents include:
• Ridge vents. Exhaust vents installed along the roof’s peak that are either covered by shingles or exposed along the ridgeline.
• Soffit vents. Continuous or individual vents installed along an attic’s soffits or eaves. Soffit vents should never be blocked by insulation.
• Gable vents or wall louvers. Exhaust vents placed in walls at gabled ends of an attic that can function as both intake and exhaust vents.
• Rafter vents. These vents ensure the soffit vents are clear so there is a channel for outside air to move into the attic at the soffits and out through the gable or ridge vent.
• Wind turbine vents. Exhaust vents that use wind power to turn an internal fan, drawing hot air from the attic. Compared to static vents, these can increase the rate at which air is expelled, depending on wind speed.
• Static vents. Individual protected exhaust vents installed near the roof’s ridge.