18-AD28D1-2
3
Installer’s Guide
E. FURNACE IN DOWNFLOW POSITION
1. DOWNFLOW COIL CONVERSION
For All Downflow Coils
a. Remove the horizontal drain pan from the coil and
discard.
b. Lay the coil on its back side.
c. Locate the 4" wide gasket material found in a plastic
bag in the document pack.
d. Attach the 4" gasket material to three sides of the
bottom of the drain pan as shown. Make sure to start
by matching up the edge of the gasket material to the
inner edge of the drain pan by the coil fins and working
outwards.
e. The gasket material can be cut or ripped easily so
that it can tailored to fit. The gasket material must
cover the three sides along the entire length of the coil
as shown in Figure 5.
For 4NXCD063 Coil Only
a. Remove the factory installed two-piece baffle assem-
bly from the apex of the coil by removing the 5/16” hex
head screws. See Figure 6.
b. Replace only the top baffle using the same screws
previously removed.
c. Installation of the 1/2” wide gasket behind the front
and back triangular baffles is required for downflow ap-
plications.
d. Remove the coil by sliding the coil out of the coil
enclosure.
e. Remove the front shield from the coil.
f. Remove the coil from the drain pan.
g. Remove the front triangular two piece baffle from the
coil (do not disassemble) and apply the 1/2” wide gasket
provided to the inside surface of the front baffle. The
gasket will need to be cut in three pieces; two 31.25"
pieces for the sides and one 17.5" piece for the bottom.
See Figure 7.
h. Remove the back triangular two piece baffle from the
coil (do not disassemble) and apply the 1/2” wide gasket
provided to the inside surface of the back baffle. The
gasket will need to be cut in three pieces; two 31.25"
pieces for the sides and one 17.5" piece for the bottom.
See Figure 7.
Figure 7
1/2" Gasket
Attach to
inside surface
of Triangular
Baffle
Attach Gasket to Inside Surfaces
Do not overlap
gasket material at
corners.
Figure 6
Remove
and
Discard
Replace
Figure 5
Attach Downflow
Bottom Gasket
Start
here
