NuAire LabGard NU-581-400, Operation And Maintenance Manual

Page: 61 / 107

OM0302
Rev 2/December 2020 Page 61 of 107
Table 7.0
Recommended Measurement Methods for Cabinet Downflow and Inflow
A. Downflow Measurement
a. Recommended Instruments: TSI 8355 Thermo anemometer
b. Procedure: Supply filter efflux is measured on a grid, in a horizontal plane 4 inches (102mm) above the bottom edge
of the window. No reading should be taken closer than 6 inches (152mm) from the inside perimeter.
c. Test Data - Inches (mm):
8” 10”
400 400
6
(152)
11.729
(298)
17.458
(443)
23.187
(589)
28.916
(735)
34.645
(880)
40.375
(1026)
500 500
6
(152)
11.797
(300)
17.594
(447)
23.391
(594)
29.188
(741)
34.985
(889)
40.782
(1036)
46.579
(1183)
52.375
(1330)
600 600
6
(152)
11.838
(301)
17.676
(449)
23.514
(597)
29.352
(746)
35.190
(894)
41.028
(1042)
46.866
(1190)
52.704
(1339)
58.542
(1487)
64.375
(1635)
6
(152)
6
(152)
10.540
(268)
10.460
(266)
15.080
(393)
14.920
(379)
19.620
(498)
19.380
(492)
Number of Readings: Average Velocity ft./min.(m/s)
d. Acceptance Criteria:
1. Average downflow velocity = 55 to 65 fpm (.28 to .33 m/s)
2. Individual readings must be 20% or + 16fpm (+ 0.08m/s) whichever is greater (factory test) or
+ 25% or + 16fpm (+ 0.08m/s) whichever is greater (field test) from the average downflow velocity.
B. Inflow Measurement
a. Recommended Instrument: Shortridge Flowhood ADM-870 or TSI 8355 Thermo anemometer.
b. Primary Procedure:
The primary procedure to determine inflow velocity uses a Direct Inflow Measurement (DIM) Instrument (i.e.
Shortridge flowhood). The DIM Instrument can be used directly on the cabinet with NO CORRECTION FACTORS
REQUIRED if operated in the local density default mode. NSF has tested the cabinet and established listed air
velocities. Use duct tape to secure the DIM Instrument to the cabinet preventing any sneak air paths from occurring.
The DIM Instrument will read inflow volume (i.e. CFM). Use the window access opening area to calculate inflow
velocity.