PART 3
EXECUTION
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NOTE: It is the designer's decision/responsibility
to decide whether, or not, to require duct air leak
testing in accordance with this section.
Subjecting duct systems to acceptance testing likely
results in higher quality ductwork. Only very
simple duct systems, such as low velocity ductwork
within a single room, do not justify DALT testing.
The designer shall indicate on the drawings a duct
construction schedule that defines the DALT test
requirements, including each applicable HVAC duct
system ID or mark, duct pressure class, duct seal
class, and duct leakage test pressure. Refer to
SMACNA Leakage Test Mnl, Appendix B, "Sample Leakage
Analysis" for guidance in determining leakage test
pressures.
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[3.1
DALT PROCEDURES
3.1.1
Instruments and personnel
Provide instruments and consumables required to accomplish the DALT field
work. Follow the same basic procedure specified below in paragraph titled
"TAB Field Work," which include maintenance of and calibration of
instruments, accuracy of measurements, preliminary procedures, field work,
workmanship and treatment of deficiencies.
3.1.2
Ductwork To Be DALT'd
From each duct system indicated as subject to DALT, the Contracting
Officer's technical representative (COTR) shall randomly select sections of
each completed duct system for testing by the Contractor. The sections
selected shall not exceed 20 percent of the total measured linear footage
of duct systems indicated as subject to DALT. Sections of duct systems
subject to DALT shall include 20 percent of main ducts, branch main ducts,
branch ducts and plenums for supply, return, exhaust, and plenum ductwork.
3.1.3
Testing
Duct air leak test (DALT) the HVAC duct sections of each system as selected
by the COTR. Use the duct class, seal class, leakage class and the leak
test pressure data indicated on the drawings, to comply with the procedures
specified in SMACNA Leakage Test Mnl. Testing shall be in accordance with
the procedures specified in SMACNA Leakage Test Mnl, except as supplemented
and modified by this section. In spite of specifications of SMACNA Leakage
Test Mnl to the contrary, ductwork of construction class of 746 Pa3-inch
water gauge static pressure and below shall be DALT'd if indicated to be
DALT'd. Complete DALT work on the COTR selected ductwork within 48 hours
after the particular ductwork was selected for DALT. DALT work shall be
conducted separately for large duct systems to enable the DALT work to be
completed in 48 hours.
3.1.4
Pre-final DALT Report
After completion of the DALT work, prepare a Pre-final DALT Report using
the reporting forms specified. Data required by those data report forms
SECTION 15950N
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