YORK INTERNATIONAL
8
Application Data
LOCATION
Of the many factors that can affect the acoustical char-
acteristics of a rooftop installation, one of the most im-
portant is the unit location. Ideally, the rooftop unit should
be installed away from sound-sensitive areas, such as
conference rooms, auditoriums and executive offices.
Possible locations could be above storage areas, hall-
ways, mechanical or utility rooms, or bathrooms.
The eco
2
air conditioning units are designed for out-
door installation. When selecting a site for installation,
be guided by the following conditions:
• Unit must be installed on a level surface.
• For the outdoor location of the unit, select a place
having a minimum sun exposure and an adequate
supply of fresh air for the condenser.
• Also avoid locations beneath windows or between
structures.
• Optional condenser coil protection should be used
for seashore locations or other harsh environments.
• The unit should be installed on a roof that is struc-
turally strong enough to support the weight of the
unit with a minimum of deflection. It is recom-
mended that the unit(s) be installed not more than
15 feet from a main support beam to provide proper
structural support and to minimize the transmission
of sound and vibration. Ideally, the center of grav-
ity should be located over a structural support or
building column.
• Location of unit(s) should also be away from build-
ing flue stacks or exhaust ventilators to prevent pos-
sible reintroduction of contaminated air through the
outside air intakes.
• Be sure the supporting structures will not obstruct
the duct, gas or wiring connections.
• Proper service clearance space of 6-feet around
the perimeter of the unit, 8-feet on one side for coil
servicing, and 12-feet to any adjacent units is re-
quired to eliminate cross contamination of exhaust
and outdoor air, and for maintenance tasks such
as coil pull and cleaning. No obstructions should
be above the condensing unit section.
RIGGING
Proper rigging and handling of the equipment is man-
datory during unloading and setting it into position to
retain warranty status.
Spreader bars must be used by cranes to prevent dam-
age to the unit casing. All lifting lugs must be used when
lifting the rooftop unit. Fork lifts will damage the rooftop
unit and are not recommended.
Care must be taken to keep the unit in the upright posi-
tion during rigging and to prevent damage to the water-
tight seams in the unit casing. Avoid unnecessary jar-
ring or rough handling.
Ground Level Locations
It is important that the units be installed on a substan-
tial base that will not settle, causing strain on the refrig-
erant lines and sheet metal and resulting in possible
leaks. A one-piece concrete slab with footers extended
below the frost line is highly recommended. Addition-
ally, the slab should be isolated from the main building
foundation to prevent noise and vibration transmission
to the building structure.
For ground level installations, precautions should be
taken to protect the unit from tampering by, or injury to,
unauthorized persons. Erecting a fence around the unit
is common practice.
ECONOMIZER
The economizer section is used for ventilation of the
conditioned space to maintain indoor air quality, and
also to reduce energy consumption by using outdoor
air cooling in lieu of mechanical cooling. If outdoor air
is appropriate for cooling, but not sufficient for the cool-
ing demand, mechanical cooling will stage on as nec-
essary until the cooling load is met.
Dual (comparative or differential) enthalpy operation is
the most accurate and efficient means of economizer
operation. The OptiLogic
TM
control monitors the return
and outside air energy content, and selects the lower of
the two for operation.
VAV SUPPLY AIR PRESSURE CONTROL
Traditional packaged rooftop systems use inlet guide
vanes (IGVs) for duct static pressure control. These con-
trol supply duct pressure by modulating dampers (intro-
ducing losses and inefficiencies) on the inlet of the fan,
open and closed. YORK’s variable frequency drives
(VFDs) offer superior fan speed control and quieter,
energy efficient operation.
