JOHNSON CONTROLS
34
FORM 102.20-N1
ISSUE DATE: 7/06/2016
SECTION 3 - HANDLING, STORAGE, AND INSTALLATION
INSTALLING OUTDOOR AHU
Before installing the outdoor AHU, identify the loose 
parts, such as the gaskets shown in Figure 22 on page 
30 through Figure 37 on page 33.
Do not damage the factory installed pipe 
chase, electrical cabinet, hoods, pipe 
stubs, door handles or roof overhang 
when installing the AHU.
Verify that the actual outside dimensions 
of the assembled curb top are less than 
the inside dimensions of the bottom of 
the AHU.
Single Piece Outdoor AHU
Use the following instructions to install a single piece 
outdoor AHU. 
1.  Make sure the curb gasket, which is shipped with 
the curb package, is installed before the AHU is 
lowered onto the curb.
2.  Lift the AHU from the ground onto the curb or 
support framework. Do not move the AHU onto 
a roof surface. 
3.  Remove the wood shipping material from the bot-
tom of the AHU. 
4.  When  setting the AHU onto the curb, 
make sure the installer positions a sealing  
gasket between the AHU and curb  
to provide a continuous airtight and watertight  
connection.
When  installing  the  AHU  on  a  steel 
frame or concrete slab, do not install a 
seal unless specied.
5.  Install the AHU according to the International 
Building Code (IBC), NEC, state, and local codes.
Multi-Piece Outdoor Solution XT AHU
Before placing the AHU on the curb, do the following:
1.  If applicable, remove the metal bracket attached 
to the cross channel, and wood shipping blocks 
before assembling the shipping splits.
2.  If the AHU is provided with shipping splits as 
shown in Figures 41 and 42 on page 35, or the 
splits were not assembled before placing the AHU 
on the curb, complete the following steps: 
1.  Use the construction grade caulk (not pro-
vided) in place of the curb top gasket and the 
following instructions to apply it. 
2.  Apply the caulk on top of curb before each 
section is placed on the curb. 
3.  Apply the caulk with a 1/2 in. diameter bead 
to make sure the seal is sealed after sections 
are pulled together. 
3.  If the AHU sections are going to be assembed be-
fore placing them on a curb, be sure the they are 
lyingonaatsurfaceduringassembly.
4.  Makesurethetopofcurbisat,andshimswere
added,ifneeded,toensurethecurbremainsat.
5.  Verify the correct sections, and orientation of each 
one.
6.  Remove the cross brace(s) (shipping supports) 
from each section’s shipping split.
7.  Remove the plastic shipping covers and supports.
8.  Remove the screws from the curb rest to release 
the wood shipping blocks. Do not remove the 
shipping blocks from under AHU until the as-
sembled AHU is ready to be lifted and placed on a 
curb. Be sure that no debris clings to the bottom of 
each section when lifted and placed onto a curb.