3.1.11
Insulation
Thickness and application of insulation materials for ductwork, piping, and
equipment shall be according to Section 15080 THERMAL INSULATION FOR
MECHANICAL SYSTEMS. Outdoor air intake ducts and plenums shall be
externally insulated [up to the point where the outdoor air reaches the
conditioning unit] [or] [up to the point where the outdoor air mixes with
the outside air stream].
3.1.12
Duct Test Holes
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NOTE: The location of duct test holes will be shown
on the drawings. Holes should be located so as to
implement the requirements of Section 15990A
TESTING, ADJUSTING, AND BALANCING OF HVAC SYSTEMS.
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Holes with closures or threaded holes with plugs shall be provided in ducts
and plenums as indicated or where necessary for the use of pitot tube in
balancing the air system. Extensions, complete with cap or plug, shall be
provided where the ducts are insulated.
3.1.13
Power Roof Ventilator Mounting
Foamed 13 mm 1/2 inch thick, closed-cell, flexible elastomer insulation
shall cover width of roof curb mounting flange. Where wood nailers are
used, holes shall be pre-drilled for fasteners.
3.1.14
Power Transmission Components Adjustment
V-belts and sheaves shall be tested for proper alignment and tension prior
to operation and after 72 hours of operation at final speed. Belts on
drive side shall be uniformly loaded, not bouncing. Alignment of direct
driven couplings shall be to within 50 percent of manufacturer's maximum
allowable range of misalignment.
3.2
PENETRATIONS
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NOTE: Where sleeves are installed in the bearing
walls, the designer must provide design details in
drawings of the structural steel sleeves. Consult
with structural engineers for the design details.
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Provide sleeves and prepared openings for duct mains, branches, and other
penetrating items, and install during the construction of the surface to be
penetrated. Cut sleeves flush with each surface. Provide sleeves for
round duct 380 mm 15 inches and smaller. Provide framed prepared openings
for round duct larger than 380 mm 15 inches and square, rectangular or oval
ducts. Sleeves and framed openings are also required where grilles,
registers, and diffusers are installed at the openings. Provide 25 mm one
inch clearance between penetrating and penetrated surfaces except at
grilles, registers, and diffusers. Pack spaces between sleeve or opening
and duct or duct insulation with mineral fiber conforming with ASTM C 553,
Type 1, Class B-2.
a.
Sleeves: Fabricate sleeves, except as otherwise specified or
SECTION 15895
Page 59
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