2.7.9
Grease Extracting Type Hoods
Grease extracting exhaust hoods shall be pre-engineered, factory fabricated
and assembled with built-in washdown systems. Grease extracting exhaust
hoods shall be of the size and type as indicated and shall be welded to the
exhaust ductwork as required by NFPA 96. Hoods shall have a minimum grease
extracting efficiency of 95 percent to be accomplished without the use of
filters, cartridges or constant running water.
2.7.9.1
Construction
Construction shall be entirely of stainless steel. Grease extraction
chamber and exhaust capture chamber shall be not less than 1.3 mm (18
gauge) 18 gauge stainless steel. Seams or joints that direct and capture
grease laden vapors shall be continuously welded, with the weld ground and
polished to match the adjacent finish where exposed. The vertical joint
where the front outside face of the hood meets the end panel of the hood
shall be continuously welded, with the weld ground and polished to match
the adjacent finish. Joints, seams, extractor chambers, and appendages
shall be mechanically sound and sealed grease tight in accordance with the
hood manufacturer's listing procedure and NFPA 96. Hoods over 3.6 m 12 feet
in length shall be provided in multiple, equal-length sections for
mounting end to end; no section shall be less than 1.8 m 6 feet in length.
Hoods comprised of multiple sections shall be factory preassembled and
provided with predrilled mounting holes and stainless steel fasteners.
Welded field joints inside the capture area and exposed to view shall be,
ground and polished to match the adjacent finish. Hoods shall be factory
preplumbed and prewired and shall have a single connection point. Hoods
built in multiple sections shall be furnished with unions and junction
boxes for field connections. Grease extracting exhaust hoods shall be of
the overhead type suitable for [wall mounting] [ceiling mounted
island-type] [free standing type with equipment base]. Steel mounting
brackets shall be provided by the manufacturer.
2.7.9.2
Pass-Over-Type
Pass-over-type grease-extracting exhaust hoods shall be installed over
griddles or fryers on service lines where prepared foods will be passed
over the hood. Hoods shall have end exhaust outlet [with upward direction]
[below serving line]. Hood shall prevent carbonization of grease in the
extraction chamber.
2.7.9.3
Automatic Washdown System
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NOTE: Designer will indicate on the drawings the
location of pumps, injector reservoir, valves, water
waste, and power connections as well as the control
station for blower and waste.
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Each grease extracting type exhaust hood shall include a built in washdown
system consisting of stainless steel wash manifold(s) with brass spray
nozzles. The washdown system shall remove accumulations of grease and
other cooking process contaminants from the internal hood surfaces using a
hot-water and detergent solution. The washdown system shall operate using
water at a temperature of not less than 60 degrees C 140 degrees F, at a
flow pressure of 275 kPa 40.0 psig minimum. A pressure reducing valve,
when supply line pressure exceeds 345 kPa 50.0 psig, shall be provided
SECTION 11400A
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