Installation Instructions 2017
VERTICAL DISCHARGE DUCT CONNECTIONS
The down ow curb accessory has been designed to
encourage duct installaon before unit placement. Duct
installaon aer the unit placement is possible but not rec-
ommended. Ducts must never be fastened to the boom
of the unit causing the base pan to be penetrated. Flexible
duct connectors in the ducts near the unit are recommend-
ed. Support all ducts by securing them to the building
structure. Weatherproof all external ductwork, joints and
roof openings with ashing and masc in accordance with
applicable codes. Ducts in an uncondioned space must be
insulated and covered with a vapor barrier.
DOWNFLOW DUCT INSTALLATION INSTRUCTIONS
1. Install duct support system in leveled and squared
curb.
2. Fabricate ductwork with 1 ½” ange out on top open-
ing and with an outside dimension that is ¼” smaller
than inside dimension of duct openings created by duct
support system.
NOTE: Ductwork is to be furnished by the contractor and is
not included with the accessory.
3. Drop duct secon through duct support opening so
that the 1 ½” ange out rests on the support channel.
NOTE: It is not necessary to aach the duct to the duct
supports with a mechanical fastener.
4. Install the included gasket material around the perime-
ter of the duct openings and around the top perimeter
of the rest of the curb to insure an air ght seal.
PARTS LIST
1 - Bottom Flashing
1 - Top Sleeve Including Duct Supports
2 - Rolls Foam Gasket Tape
DUCT INSTALLATION AFTER UNIT PLACEMENT
Duct installaon aer the unit has been placed is pos-
sible but is strongly discouraged. If the ductwork must be
installed aer the unit is placed on the curb, a duct con-
necon frame system should sll be used. Apply gasket
material to the curb and duct support frame before install-
ing the unit. Aach duct secons to the vercal surfaces of
the duct support frame using mechanical fasteners. Ducts
must never be fastened to the boom of the unit causing
the base pan to be penetrated.
Figure 3
REV. D 2/13/2017