Return air grilles should be selected for static pressures. These pressures will provide the required NC rating and conform to the return system performance characteristics.…
Category: Control Devices
Terminal boxes can sometimes be located over noisy areas (corridors, toilet areas or machine equipment rooms), rather than over quiet areas. In quiet areas casing…
The spread of an unrestricted air stream is determined by the grille bar deflection. Grilles with vertical face bars at 0° deflection will have a…
High velocities in the duct or diffuser typically generate air noise. The flow turbulence in the duct and the excessive pressure reductions in the duct…
Product research in controlling casing noise has developed a new method of reducing radiated noise. The technique is known as vortex shedding. When applied to…
Ventilating, air-conditioning, and heating ducts provide a path for fire and smoke, which can travel throughout a building. The ordinary types of dampers that are…
The diffuser or grille minimum pressure for a given air volume reflects itself in ultimate system fan horsepower requirements. A diffuser or grille with a…
Throw and occupied area air location are closely related. Both could be considered in the analysis of specific area requirements. The minimum maximum throw for…
The air volume per diffuser or grille is that which is necessary for the cooling, heating, or ventilation requirements of the area served by the…
Bottom or side outlet openings in horizontal or vertical supply ducts should be equipped with adjustable flow-equalizing devices. Figure 17-6 indicates the pronounced one-sided flow…