VIII.
ENSURE ADEQUATE OUTDOOR-AIR SUPPLY
Outdoor air is pulled from underneath the home, passed across the
outdoor-air coil, then pushed out through the roof cap exhaust.
Since the outdoor-air is pulled from beneath the home, it is very
important that the amount of ventilation panels or vents is
adequate. The underpinning vent panels or foundation vents are
rated for the amount of air that passes through them in sq in. of net
free area. Ensure that you have the correct amount of ventilation
needed for unit being installed. (See Table 8.)
IX.
CONSTRUCT
OUTDOOR-AIR
TUNNEL
(IF
RE-
QUIRED)
NOTE:
This is an OPTIONAL installation procedure to alleviate
problems that may occur with your air conditioner or heat pump
unit and various other appliances or ambient conditions.
A.
Determine if an Outdoor-Air Tunnel is Required
We recommend that this procedure be used for any one or a
combination of the following conditions:
1. A fireplace is installed and gets its fresh air from underneath
structure.
Indication to use: When conditioner or heat pump turns on,
smoke from fireplace backdrafts and enters structure.
2. A gas water heater is installed that uses fresh air from
underneath structure.
Indication to use: When your air conditioner or heat pump
turns on, the pilot light for the water heater is blown out.
3. In extremely cold regions where water pipes may freeze.
Indication to use: In winter, pipes freeze.
B.
Build Outdoor-Air Tunnel
NOTE:
The equipment and materials to install this duct work are
NOT factory supplied, nor is manufacturer responsible for deter-
mining if this procedure should be utilized.
If it is determined that an outdoor-air tunnel is required, locate unit
air intake which comes through bottom board of home and build
outdoor-air tunnel as follows:
1. Using pressure-treated 2 X 2’s or similar material, frame a
tunnel from skirting or foundation wall to entrance of
outdoor-air plenum. (See Fig. 27 for a typical air tunnel.)
2. The condensate drain must not be allowed to drain inside air
tunnel. Pipe to outside of home. (See. Fig. 28.)
CAUTION:
The tunnel and grille or screen must meet
the minimum requirements listed in Table 8 to get the
proper airflow to the unit intake. Failure to adhere to this
caution will affect the unit’s capacity and efficiency
ratings. A larger net free area may be used.
3. Attach 1-in. duct board to frame built in item 1.
4. Seal all joints thoroughly with caulking and/or duct tape.
5. Set base of walls about 2 in. in ground and backfill around
to provide a good air seal. (See Fig. 28.)
6. Install a louver or a screen over opening of air tunnel where
it penetrates skirting or foundation of home.
X.
REFRIGERANT
The unit is pre-charged at the factory to the correct operating
charge and should not require adjustment. However, should an
adjustment be required or if the unit requires service, adhere to the
following precautions.
WARNING:
Gage ports are equipped with Schrader
valves. To prevent personal injury, wear safety glasses
and gloves when handling refrigerant.
CAUTION:
Compressor damage may occur if system is
overcharged.
WARNING:
Do not vent refrigerant to atmosphere.
Recover all refrigerant before system repair or final unit
disposal to avoid personal injury or death. Use all service
ports and open all flow-control devices, including sole-
noid valves.
CARE AND MAINTENANCE
For continuing high performance, and to minimize equipment
failure, it is essential that periodic maintenance be performed on
this equipment. Consult your servicing contractor or User’s
Manual for the proper frequency of maintenance. Frequency of
maintenance may vary depending on geographic areas, such as
coastal application.
Leave User’s Manual with homeowner.
Explain system operation and maintenance procedures outlined in
User’s Manual.
TABLE 8—VENTILATION REQUIREMENTS
UNIT SIZE
MINIMUM NET FREE OPEN AREA (SQ. IN.)
018
400
024
450
030
675
036
700
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