13
+
+
+
Condensing
Furnace
-
-
- -
-
Evaporator Coil
+ +
+
< +
< +
< +
+
Blower
-
+
= Positive pressure
< +
= Pressure lower than areas with
+
−
= Negative pressure
Blower creates positive pressure.
Positive pressure extends into coil
condensate drain (no trap).
Furnace condensate does not flow
consistently when drain is at positive
pressure.
+
DIRECT
ION
OF
AI
RF
L
O
W
+
+
+
+
+
+
+
+
+
+
Condensing
Furnace
-
-
- -
-
Evaporator Coil
+
+
+
< +
< +
< +
+
Blower
-
3/4” PVC
1/2
3/4
1/2” CPVC or larger*
+
= Positive pressure
< +
= Pressure lower than areas with
+
−
= Negative pressure
+
3/4” PVC
DIRECT
ION
OF
AI
RF
L
O
W
+
+
+
+
1/2
3/4
3/4
3/4
Open
standpipe
+
+
3/4
+
+
+
+
Condensing
Furnace
-
-
- -
-
Evaporator Coil
+
+
+
< +
< +
< +
+
Blower
-
3/4” PVC
3/4
1/2” CPVC or larger*
+
= Positive pressure
< +
= Pressure lower than areas with
+
−
= Negative pressure
+
3/4” PVC
DIRECT
ION
OF
AI
RF
L
O
W
+
+
+
+
3/4
3/4
3/4
3/4
3/4
+
+
+
+
+
+
+
+
+
+
A14532
Fig. 13 -- Example of Field Drain Attachment (Not Allowed)
The field--supplied, accessory horizontal drain trap grommet is
ONLY REQUIRED FOR DIRECT VENT APPLICATIONS.
It it
NOT
required for applications using single--pipe or
ventilated combustion air venting.
NOTICE
The condensate trap extends below the side of the casing in
the horizontal position. A minimum of 2--in. (51 mm) of
clearance is required between the casing side and the furnace
platform for the trap to extend out of the casing in the
horizontal position. Allow at least 1/4--in. per foot (20 mm
per meter) of slope down.
NOTICE
FROZEN AND BURST WATER PIPE HAZARD
Failure to protect against the risk of freezing may result in
property damage.
Special precautions MUST be made if installing furnace in an
area which may drop below freezing. This can cause improper
operation or damage to equipment. If furnace environment
has the potential of freezing, the drain trap and drain line must
be protected. The use of accessory drain trap heaters, electric
heat tape and/or RV antifreeze is required for these
installations.
CAUTION
!
