ISO 5220:1981

Air distribution and air diffusion — Aerodynamic testing and rating of constant and variable dual or single duct boxes and single duct units

Specifies methods for the aerodynamic testing and rating of assemblies suitable for use with air distribution systems operating at high or low velocity and high or low pressure. The tests cover: a) leakage past a closed valve; b) casing leakage; c) characteristics of the constant or variable flow rate controller; d) degree of temperature mixing achieved by a dual duct box; e) flow rate characteristics for single duct units.