Lennox VOSB Series Installation Instructions Manual page 11

Condensate Piping Connections
VOSB036­054 indoor units have a factory-installed
condensate lift pump capable of 28 inches (711 mm) of lift
and one gravity drain connection on each side of the unit.
If using gravity drain, select one connection to use and
leave the unused connection port sealed.
Seal and plug the
when using a gravity
Disconnect the factory-installed lift pump that is connected
to the CN labeled PUMP..
VOSB072­096 indoor units have one gravity drain
connection.
CAUTION
Make sure that drain piping is properly routed and
insulated in order to prevent both leaks and condensation.
Follow these instructions exactly to ensure proper
drainage and unit operation.
1. Use the provided hose clamp to secure the
provided flexible
and insulating sleeve to the drain line stub
on the side of the indoor unit. See Figure 9.
NOTE - Take care not to over-tighten the hose clamps
this may damage the drain line stub.
036 SHOWN
SUPPLY
AIR DUCT
OPENING
AUXILIARY
DRAIN
(BOTTOM OF UNIT)
CONNECTION
(EITHER SIDE VOSB036-054)
INDOOR
UNIT
CONDENSATE HOSE CLAMP
LINE STUB
1" O.D.
Figure 9. Condensate Drain Connection
IMPORTANT
You must confirm operation of every drain and pump in
the system as part of the commissioning procedure.
2. Make a water-tight connection between the field-
provided condensate drain line and the flexible
condensate connector (1" I.D.).
lift pump connection
drain connection
condensate drain connector
RETURN
AIR DUCT
OPENING
PRIMARY
DRAIN
CONNECTION
(EITHER SIDE VOSB036-054)
AIR FLOW
(ONE SIDE VOSB072--96)
FLEXIBLE DRAIN
CONNECTOR
PVC DRAIN
1" I.D.
PIPE
INSULATION
3. See Figure 10 for applications including a single unit
and a single gravity drain. In this case, ensure that
the drain line is properly sloped (no less than 1/4 inch
per foot) and condensate lines are routed to ensure
moisture is drained away from the indoor unit.
port
Structural Ceiling
port.
Suspension Rods
Indoor Unit
Do not overtighten drain fitting.
Do not operate unit without condensate drain trap.
NOTE - Drain line should be sloped 1/4 inch per foot (18 mm per m)
AWAY from unit and should be supported as needed to prevent sagging.
Figure 10. Sloped Condensate Gravity Drain
Drain should have a slope of at least 1/4 inch per foot
and should be approved corrosion-resistant pipe.
4. See Figure 12 for applications including multiple units
and a single gravity drain. In this case, ensure that
the drain line is properly sloped (no less than 1/4 inch
per foot) and condensate lines are routed to ensure
moisture is drained away from the indoor unit. See
5. See Figure 11 for applications including a single unit
using the factory-mounted lift pump.
STRUCTURAL CEILING
SUSPENSION RODS
Figure 11. Condensate Drain with Lift Pump
6. See Figure 13 for applications including multiple units
using the internal lift pump to provide lift into a single,
correctly sized main drain. In this case, ensure that
the main drain line is properly sloped, no less than
1/4 inch per foot (6 mm per 305 mm), and that each
individual drain is connected to the main drain exactly
as shown.
11
Anti-siphon vent must extend above the
height of the coil drain pan by 2" (51 mm).
1 ft.
(305 mm) max
Clean Out
Do not glue
3"
3"
Single Unit
IMPORTANT
8 in.
3 ft. (1 m)
(203 mm)
SUPPORT
DRAIN LINE
Single Unit
3 ft.
(1 m)
Support
straps
Drain line
STRAPS