6
Downflow Conversion
“D” nomenclature models are factory equipped for dedicated
downflow operation and no field conversion is required.
Conversion to downflow must be performed in an area that
allows access to all sides prior to placing the air handler in its
final location. To keep the evaporator coil pan from sweating, the
DPI accessory insulation kit is to be used when performing this
conversion.
NOTE: The DPI kit is not supplied with this product and is to be
purchased separately. See the following chart for the correct DPI
kit.
1. Before inverting the air handler, remove all access panels, the
coil rear channel bracket, and the filter close-off panel.
2. Remove the evaporator coil and the horizontal drain pan.
3. Discard the horizontal drain pan.
4. Install the plastic plug (provided) into the vacated access
panel.
5. Remove the 2 zee coil support brackets and insulation
retaining brackets.
6. Remove the tie bracket.
7. Install the DPI Insulation Kit onto the bottom of the drain pan.
Invert Air Handler
8. Install the zee coil supports and the wrapper stiffeners.
9. Install the tie bracket.
10. Install the rear channel bracket.
11. To avoid possible condensate “blow off,” the insulation
retainers are to be laid into the evaporator coil pan as shown
in the “Evaporator Coil Pan” illustration.
Evaporator Coil Pan
To complete the conversion, slide the evaporator coil into the
chassis and attach the 3 access panels.
Evaporator Coil
NOTE: When the air handler is converted to the downflow
position, the coil may protrude above the cabinet on some
models.
Horizontal Conversion
Dedicated downflow models are not suitable for horizontal
application and must not be used for this type of installation. The
only field modification required for conversion to “Horizontal
Right-Hand” is the removal of the plastic knockouts in the
horizontal panel drain connections. To keep the horizontal drain
pan from sweating in high humidity applications, it is
recommended that a DPIH insulation accessory kit be used.
WVAHM or WAHMS Model
Insulation Kit
1824
DPI18-30/20
3030/1931/3636
DPI36-42/20
3642/3743/4860/4961
DPI48-61/20
A. Access panel
B. Return air side of unit
C. Rear channel bracket
D. Zee coil support bracket
E. Coil retaining bracket
F. Tie bracket
A
B
C
D
E
F
A. 3" (7.6 cm) flat insulation retainer (both sides)
A. Wrapper
B. Insulation jacket
C. Zee coil support
D. Wrapper stiffener
E. Drain pan insulation kit
F. Blower assembly
A
A
B
C
D
E
F
