Afm Series Model Identification; Required Ducting; Required Discharge - Atwood AFS Series Training Manual

AFM Series Model Identification

Applications – This unit is typically installed in travel trailers, 5
Installation – This series of furnace can be installed either vertically or horizontally. If installed vertically, the exhaust
port must be located at the bottom. Extra care must also be given in sealing this type of installation.
Consult the installation manual for details.
Heat Outlets – This furnace can be bottom discharged to a hard duct system, soft ducted out the back to a discharge
plate into a hard duct system or completely soft ducted from a combination of the nine outlets located on
both sides top and back of the furnace. Refer to the installation manual for the ducting requirements of
the specific model of furnace.
Serviceability - This entire furnace is serviceable without removing it from the RV when installed with the outer door
option. Therefore, there is no need to bench test it. All components are accessible by merely opening the
access door. We strongly recommend trouble-shooting the furnace while it is installed in the RV.
Power Consumption - This furnace is designed to draw between 4.3 and 11.1 amps depending on the model of the furnace.
Refer to the furnace specification decal when trouble-shooting its electrical system.

REQUIRED DUCTING

All ducts in the table are four-inch ducts except for bottom discharge as noted. Two-inch ducts can be used in place of four inch but
require (2) two-inch to replace one four-inch duct.
A bottom discharge requires no additional ducting; one additional duct can be added if required. Vertically installed units can also
be bottom discharge when right side cover panel has been removed one additional duct can be added if required.
FOR OPTIMAL PERFORMANCE use the following instructions for ducting. (Two top ducts are only to be used in addition to the
below installations and are not allowed to be used until these requirements have been met). Additional ducting added will reduce
the air flow and could cause poor heating.
 Horizontal or Vertical 4" Ducting: when using 4" ducting one duct from each side must be used. When using side ducts,
utilizing rear duct openings as the other duct will yield the best performance.
 Horizontal Bottom Discharge: This installation is for horizontally installed units and can be used with the addition of one
duct any location except the top two.
 Vertical Bottom Discharge: Installation of the furnace in a vertical mounting position can be used with the addition of one
duct any location except the top two. What is the top??

REQUIRED DISCHARGE

Models Required Discharge Area
AFM (16)(20)
AFM (25)(30)(35)
Horizontal Bottom
Vertical Bottom
System
AFMD16
4" Ducts
2
2
24 in
2
36 in
2
48 in
2
48 in
AFMD25
AFMD20 AFMD30
AFMD35
2 3
th
wheels and motor homes.
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