Filters - Lennox G61MPV?36B?045 Installation Instructions Manual

4 − Set unit in drain pan as shown in figure 19. Leave 5−1/2
inches for service clearance below unit for condensate
trap.
5 − Continue with exhaust, condensate and intake piping
installation according to instructions.
INTAKE PIPE
*Gas connector may be
used for Canadian
installation if accept-
able by local authority
having jurisdiction.
CONDENSATE LINE
FIGURE 19
G61MPV Installed in Unit Heater Applications
The G61MPV may also be installed as a unit heater. Either
suspend the furnace from roof rafters or floor joists, as
shown in figure 18, or install the furnace on a field−fabri-
cated raised platform, as shown in figure 19. The unit must
be supported at both ends and beneath the blower deck to
prevent sagging. The condensate trap must be installed
where it can be serviced at a later date.
Unit Heater Discharge Duct Guidelines
A field−fabricated and installed discharge air duct and grille
cabinet is suitable for use with the G61MPV heater. Keep
the following items in mind when constructing the cabinet.
1 − Outer dimensions of cabinet should match those of the
unit heater, so the duct/grille cabinet installs flush with
the unit heater cabinet. See figure 20.
2 − Flange both ends of duct/grille cabinet so that screws
can be used to secure cabinet to discharge end of unit
heater.
3 − To ensure proper operation, the duct/grille cabinet
must be at least 18 inches long.
EXHAUST PIPE
*GAS
CONNECTOR
RAISED
PLATFORM
SERVICE PLATFORM
Page 15
4 − Use #10−16 x 1/2 inch sheet metal screws to secure
duct/grille cabinet to unit, taking care not to damage in-
ternal components of unit heater when drilling holes or
installing screws. See figure 20.
5 − Use adjustable, double−deflection grille(s) to distribute
discharge air. Adjust static pressure to be in the 0.06
inch to 0.10 inch w.c. range.
18 in.
MIN.
DRAIN PAN
(to protect
finished
space)
NOTE − When installing duct/grille cabinet, take care not to damage internal unit
heater components when drilling holes or installing screws.
FIGURE 20
Return Air −− Horizontal Applications
Return air may be brought in only through the end of a fur-
nace installed in the horizontal position. The furnace is
equipped with a removable bottom panel to facilitate
installation. See figure 10.

Filters

This unit is not equipped with a filter or rack. A field−pro-
vided filter is required for the unit to operate properly. Table
3 lists recommended filter sizes.
A filter must be in place whenever the unit is operating.
NOTE − In upflow applications where side return air fil-
ter is installed on same side as the condensate trap, fil-
ter rack must be installed beyond condensate trap to
avoid interference.
Furnace
Cabinet Width
Side Return
17−1/2" 16 X 25 X 1 (1)
21" 16 X 25 X 1 (1)
24−1/2" 16 X 25 X 1 (2)
TABLE 3
Filter Size
Bottom Return
16 X 25 X 1 (1)
20 X 25 X 1 (1)
24 X 25 X 1 (1)