5292154-UIM-A-0317
6
Johnson Controls Unitary Products
SECTION V: DUCT CONNECTIONS
Air supply and return may be handled in one of several ways best
suited to the installation. Upflow, horizontal or downflow applications
may be used.
The vast majority of problems encountered with heating and cooling
systems can be linked to improperly designed or installed duct systems.
To help ensure a successful installation, the duct system must be prop-
erly designed and installed.
Use flexible duct connectors to minimize the transmission of vibration/
noise into the conditioned space.
Where return air duct is short, or where sound may be a problem,
acoustical duct liner should be used inside the duct. Insulation of duct
work is a must where it runs through an unheated space during the
heating season or through an uncooled space during the cooling sea-
son. The use of a vapor barrier is recommended to prevent absorption
of moisture from the surrounding air into the insulation.
The supply air duct should be properly sized by use of a transition to
match unit opening. All ducts should be suspended using flexible hang-
ers and never fastened directly to the structure. Duct work should be
fabricated and installed in accordance with local and/or national codes.
This includes the standards of the National Fire Protection Association
for Installation of Air Conditioning and Ventilating Systems, NFPA No.
90B.
SECTION VI: CONDENSATE DRAIN
CONNECTIONS
All drain lines should be pitched 1/4-inch per foot away from unit drain
pan and should be no smaller than the coil drain connection.
Route the drain line so that it doesn’t interfere with accessibility to the
coil, furnace, air handling system or filter and will not be exposed to
freezing temperatures.
Instruct the owner that the indoor coil drain pan should be inspected
and cleaned regularly to prevent odors and assure proper drainage.
Coils should be installed level or pitched slightly toward the drain end.
Suggested pitch should not exceed 1/4-inch per foot of coil.
Drain plugs can be removed using a standard 3/8” drive socket ratchet.
If the coil is provided with a secondary drain it should be piped to a loca-
tion that will give the occupant a visual warning that the primary drain is
clogged. If a secondary drain is not used it must be plugged. See Figure
24 or 25.
DO NOT
use Teflon
TM
tape, pipe thread compound, or other sealants.
The use of a sealant may cause damage and premature failure of the
drain pan.
SECTION VII: REFRIGERANT LINE
CONNECTION
FIGURE 10:
Diverter Shroud Installation
WARNING
Use 1/2” screws to connect duct work to cabinet. If pilot holes are
drilled, drill only through field duct and unit flange.
CAUTION
Equipment should never be operated without filters.
FIGURE 11:
CM Horizontal Right Application with Modular Air Handler
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FIGURE 12:
CM Horizontal Left Application with Modular Air Handler
NOTICE
When the coil is installed in an attic or above a finished ceiling, an
auxiliary drain pan must be provided under the coil as is specified by
most local building codes.
CAUTION
Avoid Double Trapping.
CAUTION
Threaded drain connections should be hand tightened, plus no more
than 1 turn.
NOTICE
If the coil is installed in a draw-thru application (modular air handler),
it is recommended to trap the primary and secondary drain line. If the
secondary drain line is not used, it must be plugged.
CAUTION
Coil is under inert gas pressure. Relieve pressure from coil by
depressing Schrader core at end of suction manifold stub out.
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