Hood Types

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Hood Types
Hood Type Description
Conventional Hood CONVENTIONAL HOOD: Constant air volume (CAV) hoods are designed to exhaust a constant air volume at all times. This system will create higher air velocities through the sash opening as the sash opening area is decreased. However, at some point a lowered sash can create turbulence at the hood face with this type of hood.
By-Pass Hood BY-PASS (CAV) HOOD: This type of hood has a by-pass opening above the sash that is increased as the sash opening is decreased. This allows a more constant air velocity at the hood face regardless of sash position.
Auxiliary Air Hood AUXILIARY AIR HOOD: A secondary air supply is delivered external to the superstructure of the hood to reduce room air consumption and thus reduce the operating cost associated with conditioning the room air.
VAV Hood VAV HOOD: Variable air volume systems are controlled by sensors that detect changes in air pressure or sash position to regulate the volume of air exhausted. This maintains a constant air velocity at the hood face regardless of sash opening. The new engineering addition contains VAV Hoods.
Perchloric Hood PERCHLORIC ACID HOOD: Designed specifically for use with perchloric acid, these hoods have special stainless steel components and the addition of a wash-down system to clean the hood interior.
Radioisotope Hood RADIOISOTOPE HOOD: These heavy duty stainless steel hoods are built to withstand the added interior load of heavy lead bricks used inside the hood for shielding. In addition, these hoods must meet additional performance guidelines approved by Illinois Department of Nuclear Safety.
Walk-In Hood WALK-IN HOOD: These hoods have a face opening extended to the floor level to accommodate large objects. They are not intended for the user to be inside the hood while performing work. This type of hood operates best with the sash opening partially closed.
Draft-Wall Hood DRAFT-WALL: The width of these hoods is extended along an entire wall to accommodate several users simultaneously.
Canopy Hood CANOPY HOOD: Designed primarily to exhaust heat and odors.
Cadaver Hood SPECIAL USE VENTILATION SYSTEMS: There are several specialized ventilation systems designed with the most appropriately engineered devices to meet unconventional safety requirements.
Biosafety Cabinet BIOSAFETY CABINETS: (BSC) offer personal, product and environmental protection. A BSC isolates biohazards from the worker by confining the contamination within an operating cabinet and removing the contaminants through High Efficiency Particulate Air (HEPA) filters. The cabinet’s intake and exhaust air is filtered through a HEPA filter before flowing into or out of the BSC work area. Any aerosols generated within the cabinet work area are contained within the BSC.
Fume Extractor LOCAL EXHUAST: This is a specialized system such as the pictured exhaust which is a flexible capture unit designed to control contaminants near the point of release by providg a high velocity vacuum at the units capture dome.
Purifying Cartridge Ventilation PURIFYING CARTRIDGE VENTILATION: This is a non-vented charcoal filtered, table top ventilation work station. It is used only with chemicals that do not exceed the PELs even if used without ventilation. It is not designed as a substitute for ventilation hoods.