American Standard YCZ036F1 Installation & Maintenance Manual page 12

ATTACHING DOWNFLOW DUCTWORK TO ROOF CURB
Supply and return air flanges are provided on the roof curb for easy
duct installation. All ductwork must be run and attached to the curb
before the unit is set into place.
Follow these guidelines for ductwork construction:
Connections to the unit should be made with three-inch canvas
connectors to minimize noise and vibration transmission.
Elbows with turning vanes or splitters are recommended to mini-
mize air noise and resistance.
The first elbow in the ductwork leaving the unit should be no closer
than two feet from the unit, to minimize noise and resistance.
13
UNIT EXTERIOR
WEATHERPROOF
THIS SEAM
UNIT DUCT
FLANGE
FIELD DUCT
UNIT EXTERIOR
UNIT DUCT FLANGE
WEATHERPROOF
THIS SEAM
FIELD DUCT
UNIT EXTERIOR
WEATHERPROOF
THIS SEAM
UNIT DUCT
FLANGE
FIELD DUCT
HORIZONTAL
Page 12
DUCTWORK
ATTACHING HORIZONTAL DUCTWORK TO UNIT
All conditioned air ductwork should be insulated to minimize heating
and cooling duct losses. Use a minimum of two (2) inches of
insulation with a vapor barrier. The outside ductwork must be
weatherproofed between the unit and the building.
When attaching ductwork to a horizontal unit, provide a flexible
watertight connection to prevent noise transmission from the unit to
the ducts. The flexible connection must be indoors and made out
of heavy canvas.
NOTE: Do not draw the canvas taut between the solid ducts.
DUCT ATTACHMENT METHODS
AIR PROOF
THIS SEAM
UNIT BASE
FIELD DUCT
UNIT DUCT
FLANGE
AIR PROOF
THIS SEAM
UNIT DUCT
UNIT BASE
FLANGE
FIELD DUCT
The following warning complies with State of California law, Proposition 65.
fiberglass wool insulation! Fiberglass dust and ceramic
fibers are believed by the State of California to cause
cancer through inhalation. Glasswool fibers may also
cause respiratory, skin, or eye irritation.
FIELD
DUCT
UNIT DUCT
FLANGE
NOT RECOMMENDED
DOWNFLOW
WARNING:
This product contains
AIR PROOF
THIS SEAM
UNIT BASE
UNIT DUCT FLANGE
UNIT BASE
WATERPROOF SEAM
WITH BUTYL OR
SILICONE
FIELD DUCT