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General Installation
Suggestions
Many times poor or non-existent caulking around the
exterior of the wall case results in air infiltration causing the
unit to run excessively. One way to check for air infiltration
is to look under and around the unit to the outdoors. If you
can see light, there is air infiltration. The first floor of a
building is where this problem most frequently occurs since
caulking the bottom of the wall case may require lying
outside in the dirt while working. This has been the cause of
many complaints about the “short cycling” of the Freeze
Sentinel
™
.
Curtains, furniture or other obstructions interfering with the
discharge air circulation will make the unit cycle turn off too
soon since the cooled (or heated) discharge air is pulled
back into the unit. This results in a room that is not
adequately heated or cooled.
Blocking the discharge air on the left side during heating
operation can result in the air getting hot enough to distort
the plastic room front. If you have a property where this may
occur we recommend a “tent card” advising room occupants
not to put anything on the unit.
Electrical Wiring Installation
Do not allow the installer to drill a hole in the wall case to
run the electrical wiring. If this is done, the wiring will have
to be run between the chassis and the edge of the wall case
so it can be connected to the unit wiring on the room side
of the wall case. When the chassis is removed for servicing or
cleaning, the insulation on the wires can be cut and can
create a safety hazard.
If the electrical connection on a 230 volt or 208 volt
installation is to be made by the line cord plugged into a
wall mounted receptacle, the receptacle should be located in
the wall under the case or close to the side of the wall case.
This installation makes a much neater appearance than a
line cord running a foot or more across the floor. The
electrician may want to place the receptacle as far from the
unit as possible to save a few feet of wiring without
considering how the installation may appear.
Central Desk Control and Remote
Thermostat Wiring
Do not allow the installer to drill a hole in the wall case to
run Central Desk Control wiring or remote thermostat wiring
to the unit terminals. CDC and remote thermostat wiring is
classified as low voltage wiring and does not have to be run in
conduit unless required by local code. CDC and remote
thermostat wiring should be run in the walls and exit the wall
under the wall case about 2" from the right hand side. The
base pan is designed with a clearance for the line cord and
the low voltage wiring can be run to the chassis in this area
also. Wire molding can be used to hold the wiring close to
the bottom of the wall case. If a sub-base is used, the wiring
can be run through the sub-base, entering the rear and
exiting through one of the front panels. When the room
cabinet is in place the CDC or remote thermostat wiring is
usually not visible to someone standing or sitting in the
room. Do not run the low voltage wiring in conduits with line
voltage wiring or near uninsulated line voltage wiring since
induced current can interrupt the low voltage controls.
Consult the electrical inspector early in the project,
especially if the power to the air conditioner is to be 265
volts, to understand what is required to comply with local
electrical codes.
Wall Case/Exterior Grille
When making an installation where the exterior grille is
flush with the exterior wall, or part of a custom
window/louver section, make sure the installer caulks the
wall case to the exterior wall, especially the bottom of the
case. Many times the air conditioners are run during
construction and the building is not closed. This can result
in excessive humidity from the warm humid air entering the
building, or the “drying out” of the building materials.
Many problems have been caused by condensate water or
rainwater running back into the building where proper
caulking has not been done.
Capacity Considerations
A unit that has a greater cooling capacity than required will
cool the room quickly but will usually not run long enough
under normal operation to adequately dehumidify the
room. Most musty odors in rooms are due to excess
humidity. Using a smaller capacity unit or using Dry Air 25
units will provide better dehumidification. The largest factor
in causing mold and mildew in the room is excess moisture,
and a smaller unit running longer or a Dry Air 25 model
can remove more moisture. Mold behind wall coverings that
do not allow water vapor to pass through - vinyl wallpaper or
oil base paints, for example - is not a problem of excessive
moisture in the room, but rather is caused by moisture
trapped in the walls.
Using a resistance heater larger than required - using a 5 kW
heater when a 3.45 kW heater would suffice for example -
may not cost any more in electrical consumption since the
larger heater will operate for less time. The “Demand
Charge” portion of the utility bill - which is based on the
highest electrical load for a period of time - may be a
significant portion of the utility bill. Some customers have
reported the “Demand Charge” actually being more than
the usage charge. In a 100 room property it would be
possible for the demand of the 5.0 kW heater versus a 3.45
kW heater to be 155 kW more than the demand charge if
the lower wattage heaters were used. Working with the utility
companies to understand their method of billing and taking
advantage of any rebates they may offer can reduce the
utility bill.
Exterior Grilles
When replacing an older unit the existing outdoor grille
may need to be changed or modified. Outdoor air flow
patterns have changed and this may dictate the need for
outdoor grille replacement or modification.
1719 Data Manual 2001 2/14/02 3:12 PM Page 57
