HVAC duct

At the ABCDF, vent gases from the neutralization reactors and the ton container effluent tanks pass through a scrubber, two carbon filters in series, and a fan, prior to entering the HVAC ducts that exit the three toxic/neutralization cubicles. These exhaust HVAC ducts lead to the final banks of activated carbon filters and to the induced draft fans. 

Equation (5.48) is an experimentally determined equation that includes a value for f. The f factor or equivalent DPA factor here accounts for the friction loss of airflow through the fin tubes in cross-flow. This equation is emperical and is limited to the specific experimental conditions for which it is derived. It is reasonable to use Eq. (5.48) for most air-cooler design and rating applications. For other applications, however, such as airflow in an HVAC duct, it is not feasible or applicable. Another experimental equation is required for the HVAC-specific applications. 

Chang,J.C.S., Foarde K.K., Vanosdell D.W. (1996) Assessment of fungal (Penicillium Chrysogenum) growth on three HVAC duct materials. Environ. Intemat., 22, 4, 425-431. 

Plenum - The space between a hanging ceiling and the floor above or roof usually contains HVAC ducts, electrical wiring, fire suppression system piping, etc. 

A modular construction approach is used for the equipment, cable trays, HVAC ducts, and a uniform spacing between walls and floors to accommodate such equipment is provided. This provides for an efficient construction schedule and efficient space utilization. Facilities with long experience for module fabrication such as ship yards are anticipated to construct the equipment. The schedule of the flow of materials, shop production, and assembly of modules will be closely integrated and supervised. 

Air ducts, HVAC ducting Engine covers Front end... 

Thermal anemometers (Fig. 18.13) are used in low-velocity gas flows with large cross-sectional area, such as in heating, ventilation, and air conditioning (HVAC) ducts. Convection cooling of the heating element is related to flow rate. The flow rate measurement is based either on the current required to maintain a constant temperature in the heating element, or alternatively on the change in temperature when the current is held constant. 

Three-dimensional (3D) computer modelling includes structures, equipment, pipe (including instrument tubing and vents/diains), HVAC ducts, and cables. The 3D model helps safety issues such as separation and fault evaluations to be addressed during the design process. With this approach, the safety of the plant is considerably improved because of reduced field changes to eliminate interferences and the field re-works required to eliminate them. It also provides for more fault evaluations, improved maintenance and inspections, and reduced operation radiation exposures. 

The primary criteria for HVAC duct woik is that it should be of noncombustible constmction. The duct work should be metal and, if at all possible, not insulated. It is important that foam plastics ate not used to insulate the interior of the air handling unit. The duct work should be separate from other building eomponents. When composites are used, they should not have plastie cores. The PVC plastic cores could greatly contribute to a eontamination loss, or the panels with the polypropylene eore will contribute to a fire. 

Closing and covering all forced air HVAC ducts in the work area with plastic or other impermeable material... 

To ensure that dust and debris do not leave the work area, it may be necessary to close forced air HVAC ducts or windows near the work area. Doors within the work area that will be used while the job is being performed must be covered with plastic sheeting or other impermeable material in a manner that allows workers to pass through, while confining dust and debris to the work area. In addition, all personnel, tools, and other items, including the exterior of containers of waste, must be free of dust and debris when leaving the work area. 

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