Abstract: A chilled-air duct for providing chilled air from an under-floor plenum space to electronics modules disposed in a rack or cabinet. The duct has a generally right triangular profile formed by a substantially vertical forward wall and a sloping rear wall. A single vent extends from a sidewall of the duct and alongside the forward wall to direct chilled air flowing through the duct to a space in front of the electronics modules. The vent extends from near a base of the duct to a top wall thereof. Air-blocks can be disposed in the vent opening to customize airflow from the duct. Flow and distribution of chilled air from the vent is at least partially equalized by the profile of the duct. The duct is freestanding and can be disposed alongside a rack or within a cabinet between a mounting frame and a sidewall thereof.