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There may be additional support required in the form of adjustable jackstands. These are
adjustable, threaded leveling rods which support the unit in each of the corners and in the center
on longer length units. Tighten the locknuts provided with each jackstand. The base plate can
rest on the floor or on vibration pads.
Floorstands are also a way of supporting the unit. These are ordered to the height of the raised
floor with leveling rods to allow adjustment. The floorstand has lips in each corner to align with
the unit which is placed on top. It is recommended that the unit frame be bolted or screwed to
the floorstand from below. Local building codes may dictate this procedure. After installation, the
raised floor is typically built around the unit.
The raised floor serves as the distribution plenum for air on downflow units. Cables, piping,
wiring raceways, inadequate floor height and any other restrictions can inhibit proper airflow.
Care should be taken to avoid restrictions.
Verify that the raised floor has been properly sized for the unit
’s airflow and the room is free of
airflow restrictions. Perforated floor tiles in the raised floor should ensure minimal pressure loss.
The raised floor must provide a minimum of 12” (305 mm) clearance. Ensure that there is
adequate clearance above the unit for service, such as replacing filters. Optional return air
plenums are available for downflow unit ducting.
2.9.
Upflow Units
Upflow units will typically be supported by vibration isolation pads and/or floorstands which may
also include leveling legs. An air discharge plenum may be factory provided which ships loose
and must be attached at the top of the unit frame. For in-room applications with supply and return
grilles, several feet of clearance must be maintained at the intake and discharge of the unit.
Alternately, an air distribution plenum must be field fabricated with supply grilles to distribute the
air. If a common plenum is utilized to connect the supply air for distribution from multiple units, it
is recommended that isolation backdraft dampers be installed on the discharge end of the unit
or somewhere prior to the common plenum to prevent cold discharge air from entering units that
may be on standby. Alternatively, we offer an AireSeal option which keeps the EC fans running
at a selectable speed between 20-50% when the unit is in standby to prevent air from entering
the units from the common plenum. Units are shipped with Electronically Commutated (EC)
motors often referred to as “plug fans”. Fan speed is factory set based on order. Fan speed can
be changed in 1% increments through the Data Alarm Processor (dap4) microprocessor
controller, by several different methods. See the dap4 User Manual for details and
recommended settings.
WARNING:
Do not operate upflow units without installing a plenum,
ductwork or guard over the fan opening(s) on the top surface of the
cabinet. Ductwork must be connected to the fan(s), or a plenum must be
installed on the top of the cabinet for protection from rotating blower
wheel(s) on upflow units. Risk of high-speed moving parts can cause
injury or death. Disconnect all local and remote electric power supplies
before working in the unit.