Condensate Drain; Duct System - Bosch LM024 Installation, Operation And Maintenance Manual

6 | CONDENSATE DRAIN

The secondary drain pan is usually placed on a
plywood base isolated from the ceiling joists by
additional layers of vibration absorbing mesh. In
both cases, a 3/4" drain connected to this
secondary pan should be run to an eave at a
location that will be noticeable.(See Figure #4)
If the air handler is located in a crawl space, the
bottom of the unit must be at least 4" above grade
to prevent flooding of the electrical parts due to
heavy rains.
Figure # 4
CONDENSATE DRAIN
The air handler should be pitched approximately 1/
4" towards the drain in both directions, to facilitate
condensate removal. A drain line must be
connected to the air handler and pitched away
from the unit a minimum of 1/8" per foot to allow
the condensate to flow away from the unit. This
connection must be in conformance with local
plumbing codes. A trap must be installed in the
condensate line to insure free condensate flow. A
vertical air vent is sometimes required to avoid air
pockets. (See Figure #5).
The length of the trap depends on the amount of
positive or negative pressure on the drain pan. A
second trap must not be included.
Figure # 5
Units are not internally trapped.
8 733 920 847 (2014/01)
The air handler should be pitched approximately 1/
4" towards the drain in both directions, to facilitate
condensate removal. (See Figure #6)
Vibration Pad is

DUCT SYSTEM

recommended
A supply air outlet collar and return air duct flange
are provided on all units to facilitate duct
connections.
A flexible connector is recommended for supply
and return air duct connections on metal duct
systems. All metal ducting should be insulated
with a minimum of one inch duct insulation to
avoid heat loss or gain and prevent condensate
forming during the cooling operation. Application
of the unit to uninsulated duct work is not
recommended as the unit's performance will be
adversely affected.
The factory provided air filter must be removed
when using a filter back return air grill.The factory
filter should be left in place on a free return
system.
If the unit will be installed in a new installation
which includes new duct work, the installation
should be designed using current ASHRAE
procedures for duct sizing. If the unit is to be
connected to existing ductwork, a check should be
made to assure that the duct system has the
capacity to handle the air required for the unit
application. If the duct system is too small, larger
ductwork should be installed. Check for existing
leaks and repair.
The duct system and all diffusers should be sized
to handle the designed air flow quietly. To
maximize sound attenuation of the unit blower, the
supply and return air plenums should be insulated.
There should be no direct straight air path thru the
return air grille into the heat pump.
Subject to change without prior notice
LM Series Heat Pump AH
Figure # 6
CAUTION: Do not connect discharge ducts
directly to the blower outlet.
LM Series Heat Pump AH