CAMP LEJEUNE, NORTH CAROLINA - Senate Judiciary Committee

12)
B
lurn or exlra[tsl air system should be balanced
before Ihe supply syslem is balanced,In conlinualion
of Ihis procedural oulline, Ihe assumplion
Is made Ihal Ihe supply syslem balance is
nol reslrained by Ihe ehausl syslem or Ibe
relurn syslem: tlowever, if such a reslrainl
exisls, Ibe exhausl syslem or Ibe rehfrn syslem
should be balanced prior 1o conlittuing will) lira
supply syslem.
The syslem is considered balanced in accordance
will) Ibese procedural slandards when
lbe value ol Ibe air q[fanlily ol each inlel or
device is measured and found Io be wilhin 10%
ot Ibe design air fluanlilies (unles Ilmre are
reasons beyond lira conhol of lhe TAB lirm--
SUPPI.Y AIR SYSTEM
PROCEDUFIES
1) Make Pilol lube Iraverses on all main s=pply
and major branch ducls 1o delermine Ihe air
dislribulion, h|vesligale any branch Ihal is very
low in capacily Io make sure Ihal no blockage
exisls.
2) Adjusl Ibe vohJm, P. dampers in life main and
branch ducls Io Ihe approximale airflow (clm)
requirement.
3) Wilhoul adjusling any lerminal device, measure
and record Ibe airllow al each leminal in Ihe
syslem. Sludy any radical condilions and correcl
Ibem. Plan Ihe se(llmnce el branch balanc
Ing. In making adjushrmnls, it is preferable Io
adjusl volume dampers inslead of exlraclors (il
inslalled) or Ibe dampers al Ibe air lerminals. If
Ihe lhrollling process at Ibe lerminal involves
closing Ibe damper !o a degree lhal generales
noise, evaluale the design chn capacily of
branch ducl.
,4) Working from Ihe branch wilh Ibe bighesl measured
capaclly 1o the branch wilh Ihe Iowesl
measured capacity, make adj|Jshnenls in each
branch. Beginning wilh Ibe oullel mosl dislanl
Item Ihe branch conneclion and proceeding Ioward
Ihe branch conneclion, make volume adlustmenls
al each lerminal as necessary. I! is
Impodanl Ihal lbe balancer uses Ibe proper "k"
lacier prescribed by Ibe air lerminal manufaclurer
for use in conjunclion wilb a padiculnr
tnslrumenl. In addilion, il is necessmy Ibal Ibe
readings al grilles, registers and diffusers be
FIGURE 5-3 A Typical Air Diffuser Velocity
Measurement
taker) in a position or number of positions prescribed
by the manufacturer of lhe air lerminal
device.
5) Flepr:nl the branch balancing unlil Ihe syslem is
it) balm)ca.
6) Verity Ihe tan capacity and operating condilions
again and make a final adjuslment in the fan
drive if necessary.
7) If the supply system was tested with dry cob -"
surface and is designed for dehumldificalion,
the air quanlily should be checked under wet
coil conditions. (Often, 10% to 15% Is added Io
lhe system setting Instead.)
8) After the supply and return exhaust systems are
balanced, the supply fan capacity should be ,
checked wilh 100% oulside air operation if Ibis
alternalive is included in system design. Appropriale
damper adjuslmenls should be made if
necessary.
9) Record Ihe "as balanced" slate of the syslem
on reporl forms for all terminals and ducl appartlus.