Installation, Operation and Maintenance Manual
VariCool
®
VAV
12
Subject to change without notice.
10.20-IM (0818)
Duct Connections
A supply air plenum must be field fabricated and attached
to the supply air outlet with a flexible duct collar. Follow
appropriate guidelines for typical ducting installation
Provide a duct length that is 3 to 4 times the diameter of
the plug fan wheel before making the first transition. Provide
turning vanes when required Attach the supply air plenum
Water Piping / Water Flow
As a standard, units shall have a shell and tube water cooled
condenser The end plates of the shell and tube condenser
are fully removable for brush cleaning when soft deposits or
scale have formed internal to the condenser coil Table 6 lists
the water flow and water pressure drops for each model unit.
Tube and tube water cooled condensers may be substituted
Water Connections
Do not reduce water inlet and outlet connections as this will
restrain water flow and increase water pressure. The inlet
water line should have a strainer accessible for periodic
cleaning Both the inlet and outlet water lines should have
field installed water shut-off valves (Gate or Ball type valves).
The shutoff valves are required for maintenance, system
repairs, or long periods of system shut down
TABLE 6 – Flow Rates/PSI Drop
Model
GPM
PSI
AVW8
24
4
AVW10
30
6
AVW12
36
7
AVW16
48
8
AVW20
60
6
AVW24
72
8
AVW26
78
10
AVW30
90
14
AVW32
96
8
AVW36
108
10
AVW40
120
6
AVW44
132
7
AVW48
144
8
AVW52
162
10
AVW56
168
12
AVW60
180
14
Recommended Field Installed
Externally
Condensate Drain Connection
Each VariCool unit has a condensate drain connection on
the Cooling Coil section For systems with the Water Side
Economizer coil option, condensate drain connections are
provided
A condensate drain trap must be field fabricated and
installed onto the 1" IPS drain connection. Each trap must
then be piped to a common waste drain Refer to Figure
5 – Condensate Trap for reference dimensions Units are
equipped with a 1" male IPS connection.
For systems with the Water Side Economizer coil option,
each individual section (Cooling Coil and Water Side
Economizer sections) must be piped individually with a
separate drain trap Once each section has a drain trap, they
may be connected together by a tee and piped to a common
waste drain
The depth of the condensate trap will vary due to the model of
the unit ordered and field requirements. The purpose of the
trap is to neutralize the negative pressure created within the
blower cabinet. Refer to the order specifications for external
static pressure (ESP) to calculate the depth required for the
“A” Dimension shown in Figure 5 The A Dimension must
equal or exceed the negative pressure developed by the
supply air blower If it does not, the condensate will not drain
properly and may allow the drain pan to overflow. The lower
leg of the trap must maintain a minimum depth of 3-1/2” to
maintain a water seal on during all operating conditions
Plug each section’s (Cooling Coil and optional Water Side
Econo Coil) opposite side drain connection as shown
Summary of Contents for VariCool VAV
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