b.
Ensure that exhaust and replacement air ductwork and air intake
sources are free from debris and dirt, through a visual inspection.
c.
Load the replacement air prefilters to the manufacturer's
recommended maximum load condition.
d.
Run the exhaust air systems, containing air pollution control
devices, for a sufficient time to obtain the manufacturer's
recommended equilibrium performance point.
[e.
Ensure that a duct leakage test is complete and accepted by the
Contracting Officer.]
3.2.2
Test Method
Test the ventilation under full load conditions according to ACGIH-2092S,
Chapter 9 and this section. Record quantitative readings on sample forms,
"Pitot Traverse Data, [Rectangular Duct] [Round Duct]," "Exhaust Air System
Test Data," and "Replacement Air System Test Data."
The test engineer is authorized to readjust and rebalance the system if
minor adjustments will bring the system into compliance with the design.
Minor adjustments include [adjusting the fan sheave] [correcting fan
rotation] [resetting dampers] [adjusting blast gates] [_____].
3.2.2.1
Smoke Test
Test each hood with smoke generators to verify contaminant control in the
capture zone, prior to performing quantitative tests on the industrial
ventilation system. Smoke simulates the contaminant. [Videotape the air
movement pattern at the worker's breathing zone for the [hoods] [booths]
[indoor firing range] [_____] [and air currents].] Comply with
restrictions on the use of incendiary devices. Inform the fire department
or other responsible parties when large quantities of smoke are expected
[or the ventilation system has internal smoke alarms].
3.2.2.2
Air Quantity Readings
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NOTE: Straight duct prior to the test point is
essential to obtain a realistic average duct
velocity. The velocity profile becomes distorted
after disturbances such as elbows, contractions,
expansions, branch entries in the exhaust system and
heating coils in the replacement air system. Look
at the drawings and determine if there is enough
straight duct to obtain 7.5 duct diameters of
straight airflow before the test points. If not,
specify the exact test points more explicitly, e.g.,
3 meters 10 feet from the positive pressure side of
the fan, or between the fan and the scrubber. Do
not use the terms upstream or downstream. In
exhaust systems the total volume flow rate test
point may be located before or after the fan or
pollution control device. In replacement air systems
the test point is placed after the fan.
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Use a pitot tube and manometer to measure the velocity pressures for the
SECTION 15951N
Page 29
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