Carrier 59MN7B - Page 18

18
+
+
+
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.
+
DIRECTION
OF
AIRFLOW
+
+
+
+
+
+
+
+
+
+
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
DIRECTION
OF
AIRFLOW
+
+
+
+
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
DIRECTION
OF
AIRFLOW
+
+
+
+
3/4
3/4
3/4
3/4
3/4
+
+
+
+
+
+
+
++
+
A14532
Fig. 16 -- Example of Field Drain Attachment (Not Allowed)