13
6.4 Non Ducted Applications
Non-Ducted Return Installations:
• Installation in a closet, an alcove, or a utility
room without a return duct requires the use
of a plenum accessory kit as it uses the area
space as a return air plenum. Minimum clear-
ances to combustible materials and service
access must be observed (see outline draw-
ing).
• This area may also be used for other purpos-
es, including an electric hot water heater, but
in no case shall a fossil fuel device be installed
and/or operated in the same closet, alcove, or
utility room.
• Review local codes to determine limitations if
the unit is installed without a return air duct.
Ducted Return
Supply Duct
Plenum
Accessory
with safety guard
CAUTION
!
HAZARDOUS VAPORS!
Do not install an air handler
with a non-ducted return in the same closet, alcove, or utility
room as a fossil fuel device. Hazardous vapors can be distributed
throughout the conditioned space and equipment damage can
result.
Ducted Return Installations:
• Installation in an attic, garage, or crawl space with
ducted supply and return air is appropriate. Minimum
clearances to combustible materials and service ac-
cess must be observed (see outline drawing).
6.5 Ducted Applications
Supply Duct
Return Duct
Non-Ducted
Return
Minimum Unit Clearance Table
To Combustible Material
(Required)
Service Clearance
(Recommended)
Sides
0”
2”
Front
0”
21”
Back
0”
0”
Inlet Duct
0”
N/A
Outlet Duct
0”
N/A
6.3 Minimum Clearance Table
