The rotating magnetic field of the resistance-start induction-run motor is produced by the out-of-phase currents in the run and start windings. Since the run winding…
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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.…
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 STRAIGHT-TUBE class of water-tube boilers includes three types: 1. Sectional-header cross drum 2. Box-header cross drum 3. Box-header longitudinal drum In the SECTIONAL-HEADER CROSS…
A STATIONARY BOILER can be defined as one having a permanent foundation and not easily moved or relocated. A popular type of stationary fire-tube boiler…
Figure 1-1 is a portable Scotch marine tire-tube boiler. The portable unit can be moved easily and requires only a minimal amount of foundation work.…