86
The 14 in. tall curbs weigh 6 lb per linear foot; 24 in. curbs weigh
9 lb per linear foot.
Due to the pressure capabilities of the 39 Series air handlers, duct
connections must be gasketed and screwed to the unit to prevent
leakage. Refer to Duct Connections section on page 90. No provi
-
sions have been made to attach the ductwork to the curb. Dimen
-
sions for inlet and discharge locations are shown in drawings pro
-
duced in
AHU
Builder
®
program.
Fig. 20 —
Splice Plate Usage
Fig. 21 —
Corner Bracket
Fig. 22 —
Fasten Cross Supports
The return and supply ducts must be supported independently
from the unit. Do not exert weight or downward force on the unit
other than minimal force required to attach ductwork.
Before the unit is installed, gasketing must be installed between
the curb and unit as shown in Fig. 23. This gasket material is sup
-
plied by the curb manufacturer. If gasket is not supplied with the
curb, recommended field-supplied gasket material is
1
/
2
-in. thick
by 2-in. wide closed cell neoprene.
When curb is installed, place gasket on curb without stretching or
overlapping the material, which can cause gaps or leaks. Butt all
joints evenly and avoid creating gaps where water can leak into
the curb. Make sure seams in gasket material overlap seams in the
curb rail. See Fig. 23 for installation details.
After gasket is in place, rig unit into position as described in Rig
-
ging and Handling section. Locate unit on curb so it is correctly
oriented with respect to the curb inlet and discharge locations.
On curb installations, lower the unit directly into place, ensuring
that the roof curb gasket does not shift or curl.
Pier or Beam Mount
As an alternative to curb mounting, units can also be mounted on
I-beams or piers. For units mounted on I-beams, the beams must
run the continuous length of the unit. If seismic criteria apply,
crosspieces must be added between the beams, according to seis
-
mic calculations. For pier-mounted units, one pier must be in
-
stalled in each corner of the unit, at the junction of the base rail
corners.
For each additional 8 ft of length, for size 03-110 units, install one
additional pier on each size of the unit at the junction of each
section split underneath the base rails. See Fig. 24 for a typical
installation.
IMPORTANT: Verify installed curb dimensions before
attempting to rig the unit and install it on the curb.
UNIT CURB
CURB SPLICE
PLATE
CURB GASKET
(OPTIONAL)
HEX NUT
LOCK
WASHER
FLAT WASHER
END
HEX HEAD
BOLT
UNIT CURB
CORNER BRACKET
SEAL STRIP
SIDE
UNIT CURB
CURB
CHANNEL
BUTT JOINTS, DO
NOT OVERLAP
GASKET SEAM
RAIL SEAM
GASKET SEAM
RAIL SEAM
WRONG METHOD
RIGHT METHOD
Fig. 23 —
Install Gasketing
