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4.1.1 Ventilation Clearances
In order to help ensure proper operation of an air-source
constructed unit, a 24" (61.0 cm) clearance for ventilation
must be maintained.
In addition, read and follow the additional ventilation
clearance guidelines below:
• Do not locate the condensing unit under an overhang
or near a wall/other equipment that will short circuit
hot air to the coil intakes.
• Do not locate condensing unit within 10’ (3.0 m) of
exhaust fans or flues.
• Do not locate the condensing unit within 48” of
another condensing unit to allow air recirculation.
4.2.1 Condensing Unit Placement Considerations
Locate the condensing unit as near as possible to the
inside air handler section in order to keep connecting
refrigerant tubing lengths to minimum and thus minimize
loss of capacity due to long lines.
Select a location where external water drainage cannot
collect around the condensing unit. Locate the unit
so roof runoff water does not pour directly on the
condensing unit. Provide gutter or other shielding at roof
level. Where snowfall is anticipated, mount the unit so
all intakes and discharges are above the maximum snow
depth for the area.
When installed at ground level, the condensing unit
should be mounted on a level concrete slab which should
extend at least 2" (5.1 cm) beyond the unit on all sides.
The top of the slab should be 2" (5.1 cm) above the ground
level. The depth of the slab below the ground level and
its structural design is governed by the type of soil and
climatic conditions. The slab must not be in contact with
any part of the building wall or foundation. The space
between the slab and the building wall prevents the
possibility of transmitting vibration to the building. When
installing a condensing unit on the roof of a building, the
structural members supporting the unit must be sufficiently
strong for the weight of the unit and mounting rails.
In areas where there is a risk of hurricane force winds,
properly sized “hurricane straps” should be used to secure
the unit to the structure or slab it is installed on.
4.2.2 Air Handler Placement Considerations
When locating the air handlers, make sure there is
sufficient free area to allow for adequate airflow to the
filters. The air handler must be situated so that it can
be serviced and the filters changed. Access panels are
located on four sides of vertical units and two sides
of horizontal units. However, consideration for the
adjustments of the drive belt and motor are important
when locating the units adjacent to walls or other units.
The cabinets of these units are well insulated. In most
installations, this construction will prevent sweating on
the outside of the unit. However, in cases where units are
installed above ceilings which are over areas where high
humidity conditions are prevalent, it is recommended
that an insulated watertight pan with adequate drain
connection be constructed and installed under the
air handler. This separate drain pan should extend
approximately 2” beyond the unit on all sides to ensure
collection of any condensate forming on the outside of the
cabinet. When this additional pan is used, the unit must
not be supported by the pan.
Air handlers are designed for a ducted supply application.
Inlet air may be ducted as required.
RC/FC Series Installation, Operation, and Maintenance Manual
