Fresh air inlets, also known as trickle ventilators, are effective for providing fresh air from outdoors to individual rooms, such as bedrooms and living rooms, in conjunction with exhaust fans operating continuously for general ventilation. Inlets are available for walls or windows in mechanical or nonpowered versions that occupants can adjust themselves. Standard self-regulating and humidity-controlled air versions are available.
Features typically include adjustable airflow (volume and direction), insulation to eliminate condensation and reduce sound penetration, and dust and insect filters. It is possible to duct small, powered makeup air systems to individual rooms, such as bedrooms, to ensure they receive fresh air.