ASHRAE Research Project 1480 Report - Food Service Technology ...

Double Island 10-Foot by 10-Foot Canopy Hood
The 10-foot deep
double island canopy hood was created by extending each of the front panels
on the 8-foot island canopy hood by one foot. Heavy
duty, light duty and combination duty
double appliance lines were evaluated under this island configuration that measured 10.00 feet
wide by 10.0 feet
deep by 2.0
feet high. The hood was equipped with twelve 19.6-inch by
19.6-
inch by 1.8 inch baffle-type grease filters, and exhausted throughh two 36.0-inch by 14.0-inch
exhaust openings. This collar
transitioned
to the laboratory’s 24.0-inch round
exhaust ductwork
through a 17.0-inch by 28.0-inch duct. The set-up is shown in Figure 8.
Figure 8. Set-Up of Double Island 10-Foot Deep
Canopy Hood
Double Island Filter Velocities
Filter
velocity measurementss were taken on the double island canopy hood at 3000, 4000, 6000
and 8000 cfm (150, 200, 300, and 400 cfm/ft). Readings were recorded for each of the 12
filters
with a 4-inch rotating vane anemometer traversing flush to the filter face. In order to apply
current best practice design, the airflow rate was biased from the rear light duty appliance line to
the front heavy-duty appliance line. The ratio chosen
was 2 to 1. By closing down the rear
exhaust collar from a 36.0-inch by 14.0- inch opening
to a 36.0-inch by 4.0-inch opening, the
airflow in the hood was redistributed from
49% front
51% rear to
65% front 35% rear. Figure 9
illustrates the change in velocity profiles.
2-7
RP-1480