11
Section A - Installation, cont’d.
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 460 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.
Clearances
The air conditioning unit clearances depend on:
1. Inlet air access used
2. Discharge air duct arrangement
3. Return air duct
4. Storage compartment location and design
A one (1) inch clearance is required on three (3) sides of
the air conditioner if the top return is used. When using the
side access for return, please allow a minimum of eight (8)
inches for the return air duct. Access to the electrical con-
nections must be provided when making the installation.
Evaporation Section:
Inlet Air
The evaporation section must have free access to room
air. A minimum of 128 square inches of FREE AREA open-
ing is required. Where the return air must be provided
through louvers or mesh screen, 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
Condenser Sec-
tion.
See FIG. A24.
Supply Duct must be insulated.
Supply Duct from air conditioner
must be equal to or greater
in IN.
2
as the floor ductwork.
Use 45 degree angle on inlets
& outlets
Electrical box access required.
Each circuit, 15 AMP HACR
breaker
REGISTER REQUIREMENTS
REQ. SIZE
MIN. QTY.
4 X 6
4
4 X 8
4
4 X 10
4
4 X 12
4
ADDITIONAL REQUIREMENTS
:
Damper required in furnace.
Vibration isolators should be
used at each mounting point.
12 VDC required for Comfort
Control operation.
INSULATED DUCT
Minimum
Maximum
40 IN.
2
60 IN.
2
(3 " depth Min.)
Optional return area.
May be used in
conjunction with side
return.
FIG. A24
Condenser air outlet ( X2 in bottom)
Must be isolated from condenser inlet air.
Condenser inlet air 2 places.
RETURN SYSTEM
Return to be 6 ft. minimum from floor.
Use wall structure for delivery to basement area.
Return grille must be filtered.
Minimum return required per duct sizing for unit to
perform within Engineering specifications. See Chart below:
DUCT SIZE
MINIMUM
MAX.
40 IN.
2
128 IN.
2
189 IN.
2
60 IN.
2
128 IN.
2
189 IN.
2
A6b. Basement Units
Manual
Compliments
of
Northwest
RV
Supply
Printed
From
http://www.nwrvsupply.com
