NuAire LabGard NU-640-400, Operation And Maintenance Manual

Page: 42 / 56

OM0291 Page 42 of 56
Rev 3 November2020
Table 7.0
Recommended Measurement Methods for Cabinet Downflow & 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):
Model Size
Window Access Height
640-400
14
6.25
(159)
13.00
(330)
19.75
(502)
26.50
(673)
33.25
(845)
40.00
(1016)
640-500
14
6.5
(165)
13.00
(330)
19.50
(495)
26.00
(660)
32.50
(826)
39.00
(991)
45.50
(1156)
52.00
(1321)
640-600
14
7.00
(178)
14.00
(356)
21.00
(533)
28.00
(711)
35.00
(889)
42.00
(1067)
49.00
(1245)
56.00
(1422)
63.00
(1600)
6
(152)
11.50
(292)
17.00
(432)
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 expressed in local density.
The DIM Instrument should also be duct taped to the cabinet to prevent 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.