6.3.10 Variable Air Volume
VAV or Variable Air Volume systems, are used to control
both the ventilation and temperature to satisfy the
requirements of a building. Central VAV systems are
considered to be the most energy efficient method to air
condition buildings. By designing central systems instead
of distributed systems, greater efficiency can be obtained.
The efficiency comes from utilizing larger fans and larger
chillers which have much higher efficiencies than small
motors and distributed air-cooled chillers. Savings are also
a result of decreased maintenance requirements.
6.3.11 The AF-600 FP Solution
While dampers and IGVs work to maintain a constant
pressure in the ductwork, an adjustable frequency drive
solution saves much more energy and reduces the
complexity of the installation. Instead of creating an
artificial pressure drop or causing a decrease in fan
efficiency, the adjustable frequency drive decreases the
speed of the fan to provide the flow and pressure required
by the system.
Centrifugal devices such as fans behave according to the
centrifugal laws. This means the fans decrease the pressure
and flow they produce as their speed is reduced. Their
power consumption is thereby significantly reduced.
The return fan is frequently controlled to maintain a fixed
difference in airflow between the supply and return. The
advanced PID controller of the adjustable frequency drive
can be used to eliminate the need for additional
controllers.
Pressure
signal
VAV boxes
Flow
Flow
Cooling coil
Heating coil
D1
D2
D3
Filter
Pressure
transmitter
Supply fan
Return fan
T
3
3
va
v2.10
Figure 6.9
Application Set-up Examples
AF-600 FP Design and Installation Guide
6-10
DET-768A
6
6
Summary of Contents for AF-600 FP Series
Page 1: ...AF 600 FPTM Fan Pump Drive Design and Installation Guide GE ...
Page 17: ...Introduction AF 600 FP Design and Installation Guide 1 10 DET 768A 1 1 ...
Page 39: ...Start Up and Functional Tes AF 600 FP Design and Installation Guide 3 6 DET 768A 3 3 ...
Page 57: ...About Programming AF 600 FP Design and Installation Guide 5 14 DET 768A 5 5 ...
Page 73: ...Application Set up Examples AF 600 FP Design and Installation Guide 6 16 DET 768A 6 6 ...
Page 83: ...Installation Consideration AF 600 FP Design and Installation Guide 7 10 DET 768A 7 7 ...
Page 87: ...Status Messages AF 600 FP Design and Installation Guide 8 4 DET 768A 8 8 ...
Page 97: ...Warnings and Alarms AF 600 FP Design and Installation Guide 9 10 DET 768A 9 9 ...
Page 101: ...Basic Troubleshooting AF 600 FP Design and Installation Guide 10 4 DET 768A 10 0 ...
Page 103: ...Terminal and Applicable Wir AF 600 FP Design and Installation Guide 11 2 DET 768A 11 1 ...