Accurex 470400 Installation, Operation And Maintenance Manual page 19

Testing Hood Air Volume
Baffle Filters Style Hoods with the Shortridge Meter
A. Exhaust
With all the filters in place, determine the total hood exhaust
volume with a shortridge meter as follows:
1. All cooking equipment should be on. If the hood has
internal short circuit make-up air, it should be turned off.
. Measuring Velocities
• Set up the shortridge meter.
• For 0 in. (500 mm) wide filters, position the grid as
shown in Fig. 4 and 5. Average two measurements.
• For 16 in. (400 mm) wide filters position the grid as
shown in Fig. 6.
• Take velocity readings for each filter.
3. *Calculate each filter's volumetric flow rate by summing
the flow rate of each individual filter in the hood.
4. *Calculate the total hood's volumetric flow rate by
summing the flow rate of each individual filter in the hood.
*Note: For best accuracy multiply the velocity of each filter by its
conversion factor and sum the flow rates Averaging the velocity
measured for all filters may cause error.
Nominal Filter Size (H x L)
Inches Millimeters
16 x 16
16 x 0
0 x 16
0 x 0
Example: Measured velocities for 0 x 0 filter = 185 and 189 fpm
Average Velocity
(Imperial)
(Metric)
Flow rate for one filter =
Total hood flow rate
Imperial
Conversion Factor
400 x 400
400 x 500
500 x 400
500 x 500
Sum of Velocity Readings
=
Number of Readings
185 + 189
= = 187.0 fpm

3383 + 3456
= 340 m/hr
=

Conversion Average
x
Factor Velocity
= .40 x 187.0 fpm
= .3 x 340 m/hr
(Filter 1
= + ... +
Flow Rate)
= 448.8 + 457.8 + 437.5 + 444.8 = 1788.9 cfm
= 763 + 778 + 743 + 756
Metric
Conversion Factor
1.66 .154
.10 .195
1.96 .18
.40 .3
= 448.8 cfm
= 763 m 3 /hr
(Filter X
Flow Rate)
= 3040 m 3
.75 in.
Fig. 4
17.5 in.
Fig. 5
/hr
Fig. 6
Fig. 3
14 in.
10 in.
6 in.
10 in.
14 in.
.75 in.
10 in.
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