A roof ventilation system is a type of ventilation that allows continual flow of outside air through the attic, protecting the efficiency of the insulation and helping to lower temperatures in the living space. It consists of a balance between air intake and air exhaust.
A roof ventilation system keeps the house more comfortable in summer and guards against moist, heated air building up in winter. There are two kinds of vents: inlet vents and outlet vents. Having only one or the other is the equivalent of having neither. For proper attic and roof ventilation, both types of vents are essential, operating with equal amounts of net-free airflow.