Descriptions of Components for the Portable Clean Hood
HEPA Filter:
This filter was designed to be used in a drop in
ceiling, but due to its low cost we used it in our design. The
filter is capable of delivering Class 10 air.
MACC 10/2x2 HEPA Ceiling Grid Module
EACI ENVIRCO (Environmental Air Control, INC.)
6701 Jefferson N.E.
Albuquerque, NM 97109, USA
(505) 345-3561, (800) 545-6598
Plexiglass:
The entire viewing area of the hood are enclosed with
1/8" plexiglass. This allows the analyst to easily see everything
in the hood. Plexiglass was chosen for its low cost, cleanliness,
and machinability.
Polypropylene:
The base of the hood is constructed entirely of
1/2" polypropylene (stress relieved). This material is relatively
clean and easy to machine. The base of the hood consists of a
grooved top plate to allow equipment to sit level on top while
allowing the clean air flow to pass by the sample and down into
the lower base case. The remainder of the base consists of a
solid box with a 6" PVC tubing connection directly in the
center of the base. Additionally there is a polypropylene plate
spaced about 1" above the opening to prevent the central
air a more rapid and direct draw out the PVC pipe.
Exhaust fan:
An 8" inert exhaust fan draws the air and fumes
out of the hood and directly out into the buildings chemical hood
system. The fan is made be Nalgene and sold through Fisher Scientific.
The exact model of fan is not currently available but the following
are the original specifications: Nalgene Totally Enclosed Fan-Cooled
Lab Blowers with PVC Impeller Wheel, FRP housing (Nalgene Cat# 71530-0050). The fan had an 8" inlet and outlet ports.
Steel Frame:
The entire frame was constructed from 1.25"
angle steel. Once completed the steel was chemically sealed with
an Epoxy paint. Additionally, a 110 VAC outlet was installed
onto the metal frame just below the polypropylene base.