5
with a trap to insure positive drainage.
Whether a remote or direct drain system is
used, condensate should not be permitted to
collect beneath the home.
e)
When mounting under the home, inset from
the perimeter, the conditioned air outlet will
be at the top. In this case, an installer
supplied gasket must seal between the unit
and the home underbody. The outlet air will
feed directly into the home supply duct in
this case. Remember to remove
only
the
blower shipping plate associated with the
outlet desired. Keep in mind that any home
skirting must be ventilated to allow free air
access to and from the condenser with
minimal recirculation.
f)
When pad mounting, the unit should be
flush with and under the home. Skirting may
be employed if it allows access to the unit
wirebox and does not interfere with free air
access to and from the condenser. Do not
allow the pad to contact any foundation or
home support member. This will prevent
unit vibration from entering the home.
g)
Remaining duct adaptors (one tabbed and
one plate mounted) are for use in connecting
to the home as required.
6. DUCT AND REGISTER SPECIFICATIONS
GENERAL INFORMATION
All supply air ducts, registers, return air ducts, return air filters
and filter retainers must be supplied by the installer.
Any ducting (supply or return) exposed to a heat source or
outdoor environment must be sealed and insulated to prevent
heat gain and decreased system performance.
When ducting is attached directly to the air conditioner
cabinet, the installer must utilize the screw openings already
provided.
DANGER - SHOCK HAZARD
Drilling new openings and inserting screws may damage
either the refrigeration circuit or electrical wiring causing
possible equipment damage, personal injury or death.
Do not drill or cut any openings into the air conditioner.
RV Products strongly recommends that all air distribution
designs be tested by the home manufacturer. This is to ensure
that air volume, distribution and noise levels can be optimized.
GUIDELINES FOR SUPPLY AIR DUCTING
Total free area inside the supply duct can be no less than 42
square inches. Ducting with more free area can improve
system performance.
To decrease restriction and increase air flow, the ducting
should make as few bends and turns as possible. When
corners or turns are required, it is recommended that these
turns be radiused and as gradual as possible.
The supply duct, unless made of an insulating material, must
be insulated to prevent condensation from collecting on its
exterior. Moisture condensation within the ceiling or wall
cavity can damage insulation, stain vehicle interiors or create
odors. 1/8", 3 pound density fiberglass or closed cell foam
insulation has proven effective for this purpose.
Any ducting exposed to heat sources must be further
insulated to prevent significant performance degradation due
to heat gain. An example of an area capable of creating
significant heat gain is the roof area which can sometimes
experience temperatures of 160° or more when exposed to
direct sunlight. For ducting in or near the ceiling, it is
impossible to provide “too much” thermal insulation.
GUIDELINES FOR SUPPLY REGISTERS
Total free area provided by the supply air registers should
equal a minimum of 72 square inches.
Free area is the size of the opening(s) that remain in a grille or
louvered panel after restrictions (the louvers) are subtracted.
Most metal and plastic grilles average 30% to 60% open. That
is the actual “free area” for the grille will be 30% to 60% of the
total opening area.
GUIDELINES FOR RETURN AIR
DUCTING AND FILTERS
All return air must be filtered. A 1-inch thick disposable fiberglass filter
is recommended. A washable filter is acceptable if supported by a mesh
or grille to prevent collapse. Should the return air filter and filter
retainer be located in the floor, a traffic duty grille will be required. The
return air filter should be located in an area where:
a)
drapes or bed sheets cannot block the
opening;
b)
the consumer can gain easy access for
servicing.
