Performance of New Ceiling and Wall Ventilation Air Inlets

Abstract

This article presents results of performance tests of new passive automatic ceiling and wall inlets for livestock buildings. A ceiling inlet with a round insulated baffle and a wall inlet with a rectangular insulated baffle were assessed for their ability to maintain a steady exit air velocity over a range of static pressures. The fiberglass inlets were evaluated for average exit velocities, airflow rates, baffle restraining force, and exit velocity profiles under several inlet settings and static pressures. Airflows through the wall and ceiling inlets were 419 and 335 L/s (887 and 711 cfm), respectively, at a static pressure of 31.25 Pa (0.125 in. H2O) and an average exit air velocity of 5.2 m/s (1,022 fpm). Both inlets achieved relatively constant average exit velocities over a range of typical building static pressures. The horizontal or slightly upward direction of the air jet produced by the inlets enhances jet attachment to the ceiling during cold weather.