Specifications

SCF-050 Manual
16
Connecting To Existing Duct Work
Figure 8
The SCF-050 may be connected to the existing ductwork of a Gas, Oil or Electric / Heat Pump
furnace. The duct work of the furnaces may not be hooked in series with each other. This means the
Warm Supply Air of the SCF-050 may not be hooked the Cold Air Return of the existing furnace. See
example in figure 8 above. The Cold Air return of the SCF-050 is connected to the Return Air Duct of
the existing furnace. The Warm Air Supply of the SCF-050 connects to the Supply Plenum of the
existing furnace. Back Draft Dampers must be used in the SCF-050 Warm Air duct and in the Warm
Air Plenum of the existing furnace to prevent the air flow from reversing. It is recommended to enter
the Supply plenum of the existing furnace above the Air Conditioning A coil. The materials used for
the Warm-Air supply duct must have a minimum temperature rating of 250 degrees F. The Plenum of
the SCF-050 must be constructed of metal. Once installed as an Add On furnace check the Static
pressures in the ductwork to make sure they do not exceed the limits on the existing Central furnace or
of the SCF 050. Running both furnaces at the same time should not cause any nuisance tripping of the
High Limits in either unit.
Follow all instructions when connecting to existing ductwork. Connecting the Warm Air Supply
to the Cold Air return may cause harm to the existing furnace and may void the warranty of
both the existing furnace and the SCF-050.
CAUTION: Do not connect an air conditioning system to this unit.