The open area of air flow intake increases as you progress down the duct towards its end. Air is drawn into the duct evenly along its length at the apex of the attic. The smaller open area of air flow intake are required near the fan due to increased pressure. The larger open area of air flow intake along the length compensate for an ever decreasing pressure allowing air to be taken in evenly along the entire length of the duct. The duct is located adjacent to the attic's peak so that the duct's intake is the hottest air.
Hot air is exhausted from the attic during summer months which lowers air conditioning costs.
The attic is vented during winter months to prevent ice dam formation. No passive roof vents are required on top of the roof. Eave vents are still required as a source of air intake into the attic cavity. The SolarAttic Ridge Vent supplants the need for roof vents of all types including passive, powered or specially designed ridge vent systems on the roof's peak.