9
Section A - Installation, cont’d.
will have the “D” slot in the coil header.
A6b. 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 louvered grill with 330
square inches for supply air and a louvered grill on oppo-
site side of coach (330 square inches) for discharge air.
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 lou-
vered panel after the restrictions are taken away. For ex-
ample, 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 transmit-
tance 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 (con-
denser) 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.
Indoor Section:
Clearances
The minimum clearances to the evaporator are zero inches
to the bottom, top, left and right sides. Access to the elec-
trical 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 or 180 square inches
of FREE AREA open-
ing is required. Where the return air must be provided
through louvers or mesh scree, the FREE AREA percent-
age of the material used shall be taken into consideration
when making this determination. An example of how to
determine FREE AREA is included under “
Outdoor Sec-
tion”.
Grills and Registers
Note:
The return air grill must have the same square sur-
face 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 grill must be filtered and accessible for clean-
ing and replacement.
Outlet Air
The central air conditioning unit is designed to use a dis-
charge 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 operating. 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.
Note:
If the air conditioning unit is attached to the central
furnace, a damper must be installed at the furnace outlet
to prevent cold air from circulating through the furnace heat
exchanger, unless furnace is so equipped to utilize the built-
in furnace relay.
A6b. Basement Units
Manual
Compliments
of
Northwest
RV
Supply
Printed
From
http://www.nwrvsupply.com
