15891-2
DUCT INSULATION
d. Density: 3 lb/cu. ft.
e. Equal to Owen-Corming series 703 FRK-25
C. Exterior Duct Insulation
1. | Closed cellular flexible plastic
a. 2 inch thick
b. Thermal conductivity at @ 75°F: 0.25/inch minimum
c. ULL. flame spread: 25 or less
d. Finish: Armaflex WB finish with 10x10 Leno Weave glass mesh
PART 3 - EXECUTION
3.1
APPLICATION
A. Duct Insulation:
1. Required on all outside air intakes from exterior wall or roof to duct
termination including fan casing.
2. Required on all heated or cooled supply air ductwork from air handling unit to
duct termination including air handler if not factory insulated.
3. Required on exhaust ductwork from outside closure damper to exterior wall or
roof.
4. Insulate entire ducts and seal to prevent condensation on cold surfaces,
including standing seams, support straps, and other metal attached to the
ductwork.
5. Insulate access doors and gaskets to prevent metal to metal contact.
Apply insulation to clean, dry ductwork.
Remove damaged insulation and replace to the satisfaction of the Engineer at no
additional cost to the Owner.
Use sealing tapes 3 inches wide, reinforced, pressure sensitive type, SMACNA
approved. Tapes that do not adhere to insulation shall be cause for rejection of all
insulation work. Only apply tape when ambient temperature is between 40°F and
100°F.
Closed cellular plastic:
1. Obtain adhesive from the insulation manufacturer and apply to entire duct
surface, and all joints.
2. Apply in strict accordance with manufacturer’s instructions and
recommendations.
Fiberglass Ductwrap:
1. Apply insulation adhesive in 4" wide strips, 8" on center, circumferentially
around duct.
2. Tightly wrap insulation around duct with all joints butted and longitudinal
joint overlapped 2 inches.
3. On the bottom of ductwork over 24 inches wide, provide and install
mechanical fasteners at not more than 18" on center.
4. Tape all joints with 3" wide tape.
5. Tape over protruding stick pins.
Rigid Fiberglass Duct Board:
1. Impale insulation on welded pins or stick clips.
2. Install pins not more than 3" from edges, and 12" on center.
13089K
