Specifications

6 | CONDENSATE DRAIN SM AH Series Heat Pump
SM AH Series Heat Pump873392084 (2013/11) Subject to change without prior notice
Mounting Horizontal Air Handler Units
While horizontal units may be installed on any level
surface strong enough to hold their weight, they
are typically suspended above a ceiling by
threaded rods. The rods are usually attached to the
unit corners by hanger bracket kit. (See Figure #5).
The rods must be securely anchored to the ceiling.
Refer to the hanging bracket assembly and
installation instructions for details. All units
require four mounting brackets at the corners.
Horizontal units installed above the ceiling must
conform to all local codes. An auxiliary drain pan if
required by code, should be at least four inches
larger than the bottom of the heat pump. Plumbing
connected to the heat pump must not come in
direct contact with joists, trusses, walls, etc.
Figure # 5
Some applications require an attic floor
installation of the horizontal air handler unit. In
this case the unit should be set in a full size
secondary drain pan on top of a vibration
absorbing mesh. The secondary drain pan prevents
possible condensate overflow or water leakage
damage to the ceiling. 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. If the
unit 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.
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.
(Units are not internally trapped). A vertical air
vent is sometimes required to avoid air pockets.
(See Figure #6).
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 # 6
The condensing unit should be pitched
approximately 1/4" towards the drain in both
directions, to facilitate condensate removal. (See
Figure #6)
Figure # 7
If equipped with float style condensate overflow
switch, final adjustment must be made in the
field.
Make sure that the unused drain pan opening is
plugged prior to operating the air handler.