PROCESS #9-1238 Rev 2 April/2021 Best Products. | Best Performance. | Best Protection. Page 6 of 10
NuAire, Inc. | 2100 Fernbrook Lane | Plymouth, MN 55447 | U.S.A | ph: 763.553.1270 | fx: 763.553.0459 | tf: 800.328.3352 | www.nuaire.com
5. The airflow velocity through the work access opening shall vary according to the actual window
height, however the volume will remain relatively constant. Where specified, variable air
volume controllers shall be installed, by other trades, thereby increasing/decreasing the average
volume through the work access opening to produce a constant inflow velocity as the sash is
raised or lowered, respectively. Window position sensors shall be installed on the hoods sash to
control the variable air volume valves.
6. The solid polypropylene work surface shall form an integral part of the work space, be leak-tight
and recessed ½-inch below the front spill lip/airfoil to contain liquid from spilling to the floor.
The area beneath the work surface (dead air space) shall be maintained under a negative
pressure.
7. The work zone shall be illuminated by an internally/externally mounted, gas-tight,
polypropylene, fluorescent lamp fixture that shall be constructed from ¼-inch material,
including the clear plastic lens. The fixture shall provide an average of 100 foot-candles,
measured at the work surface. The lamp shall use two T8 bulbs and a thermally protected, UL
Listed electronic ballast with automatic reset. All lamps shall be easily replaceable using simple
tools.
8. All electronic controls shall be housed in a separate gastight polypropylene enclosure and shall
be accessible by removing control panel. The control panel shall be constructed from
polypropylene, recessed flush in the hood post and shall expose only the plastic bezels of rocker
switches and lamps, etc.
D. Fume Hood Construction:
1. The cabinet workspace, plumbing chase, structural support members and bottom shall be
constructed from ½-inch fully stress relieved, refrigerator white, polypropylene sheet stock. All
sections are to be reinforced where necessary and continuously heat seam welded to form a
rigid structure with all exterior welds finished flush with the surrounding surfaces. All cabinet
surfaces shall be square within 1/8-inch in all dimensions.
2. All seams shall be welded using a minimum of 5/32-inch diameter round/oval welding rod. The
non-exposed interior welds of all panels (i.e. sides, back, bottom, etc.) that are exposed to the
exterior shall be double welded for added strength. All interior welds shall be water/air-tight
and need not be finished flush to adjoining surfaces.
3. The polypropylene workspace shall be enclosed on both sidewalls by a clear 4-inch wide
plumbing chase. The chase shall extend the full height and width of the work zone. Access
panels shall be provided on both the exterior and interior (workspace) walls of the chase. All
panels shall be ¼-inch material and mount flush to the surrounding material. They shall be sized
to provide sufficient access for maintenance and installation of services and controls. All ¼-inch
access panels shall be fastened with #8-32 x ½-inch polypropylene flathead screws.
4. Where specified, the workspace interior and exhaust plenum shall be constructed from flame
retardant polypropylene, or lined with PVDF or TFE. The lining shall use 1/8-inch virgin sheet
stock material and shall overlay the polypropylene surface such that the interior dimensions are
identical. The liner shall be heat-welded together to form a ridged structure and fastened to the
polypropylene by ¼-inch by 20 flathead screws of like material, where required.
