An air compartment maintained under positive or negative pressure and connected to one or more distributing ducts.

an air compartment connecting one or more ducts with the heating or cooling unit; any enlarged section within an air duct with several duct, grille, or diffuser, connections

Compartment in which air is at higher than atmospheric pressure.

Located between the throttle body and the runners of an intake manifold, it is just like a chamber to distribute the intake charge and improve engine breathing.

A chamber, located between the throttle body and the runners of an intake manifold, used to distribute the intake charge evenly and to enhance engine breathing.