Operating instructions

41
B. BASEMENT UNITS
MODELS 39335 AND 39125
OUTDOOR SECTION:
The condenser coil is designed to have a fresh supply of air.
If skirting is installed, allow a 15" x 22" opening (330 square
inches) for supply air and a 15" x 22" opening (330 square
inches) for discharge air. Use the cross flow method for good
air circulation.
DO NOT TOTALLY ENCLOSE THE UNDERSIDE OF THE
UNIT. AIR CIRCULATION PREVENTS HEAT FROM BUILD-
ING UNDER UNIT AND YOUR SYSTEM WILL PERFORM
AS DESIGNED.
The condenser section is a "blow-through" type. When the
face of the coil is positioned behind a louvered or other type of
restrictive opening, the FREE AREA of the opening must be
at least 260 square inches.
FREE AREA — is the opening that remains in a grill or
louvered panel after the restrictions are taken away. For
example, an opening of 10 x 20 inches has 200 square inches.
When this opening is covered with a grill that is 56 percent
open, the FREE AREA is (200 x .56), 112 square inches.
Expanded and perforated metal grills in general vary from 30
percent to 60 percent open. Be certain that 260 square
inches of FREE AREA is available to the face of the con-
denser.
NOTE: Service access must always be supplied either as
clearance or as a defined access panel.
MOUNTING
Vibration eliminators are supplied to prevent the transmittance
of vibration into the living area.
The air conditioning unit may be attached to rails beneath the
vehicle, attached to the frame, or mounted directly to the floor
of some vehicles.
Unit should be mounted with a tilt toward the rear (condenser)
a half-bubble using a level. Unit rear should be 1/4" lower
than the front.
SERVICE ACCESS
Be sure NOT to block the inlet or discharge air, or service
access, when mounting.
8
8
2
2
2
1/2
1/2
1/2
1/2
36
64
EXAMPLE OF HOW TO DETERMINE FREE
AREA OR % OPEN AREA:
TOTAL AREA = 8 X 8 = 64
FREE AREA = 2 X 2 X 9 openings
=36
% OPEN AREA = = 56%
INDOOR SECTION
CLEARANCES
The minimum clearances to the evaporator are zero inches to
the bottom, top, left and right sides. Access to the electrical
connections and drain connection must be provided when
making the installation.
Be sure to allow sufficient room to service the
electrical components.
INLET AIR
The evaporator section must have free access to room air. A
minimum of 180 square inches of FREE AREA opening is
required. Where the return air must be provided through
louvers or mesh screen, the FREE AREA percentage of the
material used shall be taken into consideration when making
this determination. An example of how to determine FREE
AREA is included under "2. OUTDOOR SECTION".
GRILLS AND REGISTERS:
NOTE: The return air grill must have the same square
surface as the coil face (15"H x 17"L).
For each air conditioning system, there must be a return
grill to bring cabin air back into the unit. There must also be
at least four discharge grills per unit.
Each return air grille must be filtered and accessible for
cleaning or replacement.
OUTLET AIR
The central air conditioning unit is designed to use a discharge
air duct with a static pressure of .10 to .25 inches water
column. Proper duct size is necessary to maintain proper air
flow without loss of static pressure and provide good air
circulation.
All air handling ducts must be properly insulated to prevent
condensation forming on their surface during operation. A
vapor barrier must also be supplied on the outer surface of the
insulation to prevent moisture from traveling through the
insulation and condensing on the cold ductwork.