CAMP LEJEUNE, NORTH CAROLINA - Senate Judiciary Committee

BASIC AIR SYSTEM
PROCEDURES
"Preliminary TAB Procedures" covered
Ihe preparation work lhat must he done prior !o Ihe
actual testing, adustiqg and bnlnnP.in.q of tile IVAC
systems on the Job. Confirm Ilmt lhese peliminnry
procedures have been completed and check lisls
prepared. Do not attempt to balance a system before
Installation has been completed and the system is
ready to be balanced.
The following balancing procedures are basic Io nil
types of air systems.
1) Confirm Ihat every ilem affecting tile aiHIow of a
ducl system Is ready for tile TAB woJk, such as
doors and windows being closed, ceiling liles
(return plenums) in place, etc.
2) Confirm Ihal all aulomalic control devices will
not affecl TAB operations.
3) Establish the conditions for Ihe maximum demand
system airflow which generally is a cool-
4)
Ing application with "welled" coils.
After verifying Ihal all dampers are open or set,
sled all related systems (relurn, exhaust, etc.)
and the system being balanced with each fan
running al Ihe design speed (rpm). Upon start-
Ing each fan, #Immdiately check 11m fnl reeler
amperage. If lhe amperage exceeds lhe
nameplale full load amperage, slap the fnn Io
delermine lhe cause or Io make lhe necessary
adjuslmenls.
5) Again confirm Ilml 11 related syslPmfs|vleg
each nrP.n wilhin Ihe space b.h|.q
are operaltng. If Ihey are not, prn.ure differences,
and Inlillrnlion or exfiltralion may adversely
influence Ihe balancing. Pceliminnry
studies will have revealed whether or not Ihe
supply air quanlily exceeds lhe exhausl air
qunnlily from each area. Positive and negalIve
pressure zones should be Identified at the time.
6) If a supply fan i. connected to a rolurn air syslem
and an oulside air inlake, sot 11 syslem
AIR SYSTEM AB
PROCEDURES
dampers and conlrols so that the air relurned
from Ihe individual rooms or areas supplied by
lhe fan is relurned via Ihe relaled relurn air
syslem. Normally lhis will Involve opening an.
o|lsidP, air damper Io the minimum position,
opeling Ihe relum air damper, nnd closing
exhnusl nit nnd relief air dampers. (If lhe supply
syslem is nssocinled with a return air syslem
nnd/or an independenl exhaust system, make
mre nil syslems are opernling and all relaled
dampers are sel properly for Ihe TAB work.)
7) t3elermine the volume of air being moved by lhe
supply fnn nl design rpm by one or more of lhe
following melhods. The preferred methods are:
a) Pilol lube lraverse of main duct or dcls
leaving fan discha=ge.
b) Fan curves (r fan performance chads. In
order 1o delermine fan performance using a
fan curve or performance rating chad, il is
necessary Io take amperage and voltage
readings. In addition, a slallc pressure read-
Ing across lhe fan must be recorded. Wilh
rpm, brake horsepower and static pressure,
lhe fan mnnufacturer’s data sheets may be
med Io delermlne Ihe aidlow (cfm) predid.led
by Ihe Hnufaclurer. Fan perfbrrnnce
cnn dUvinle from Ihe fan curves if
"sy.lem effect" or olher syslem installalion
defecls are present.
c) Anemomeler readings across coils, fillers,
ned/or dampers on the Inlnke side of the fan.
1-hi i used ns an approxlmalion only.
0) If Ihe spply fan voh=me is not within plus or
minus 10% of the design capacity at design
rpm, dtermine the reason by reviewing all syslem
conditions, procedures and recorded dale.
Check and record the air pressure drop across
fillers, ’coils, eliminators, sound traps, elc., to
see if excessive loss Is occurring. Paflicularly
Iudy dcl and casing conditions at Ihe fan inlet
and outlel.