Auto-Zone Control Systems Zoning Design Guide (Version 01B) - Manual (Page 5)

Auto-Zone Systems 5
Zoning Design Guide
How Auto-Zone Works
The Auto-Zone control system converts single-zone
constant volume rooftop packaged or split system
HVAC units into variable air volume/variable tempera-
ture multiple zone systems. The microprocessor based
Zone Manager calculates the heating and cooling re-
quirements for each zone based on real time informa-
tion received from each Zone Controller/Damper. The
Zone Manager then directs the HVAC unit to provide
the appropriate amount of heating, cooling, and venti-
lation to satisfy each zone’s requirements. A bypass
damper controlled, by a static air pressure sensor, modu-
lates a bypass damper to maintain constant duct pres-
sure.
The Auto-Zone system uses a unique 3 tier approach to
controlling the system:
•
Voting Zones
•
System Demand
•
Priority
This 3 tier system works in an integrated fashion to
maintain proper control of the equipment and effective
control of comfort in the zone.
H
E
A
T
I
N
G
C
O
O
L
I
N
G
F
I
L
T
E
R
NORMAL
WARMER
COOLER OVR
W/OVERRIDE AND SETPOINT ADJUST
ZONE
CONTROLLER
MODULATING
DAMPER
AC LINE
CONNECT TO OTHER
ZONE MANAGERS
CONNECT TO OTHER
ZONE CONTROLLERS
OR CV UNITS
VOLTAGE
ZONE MANAGER
SUPPLY AIR
MODULATING
CONTROL CABLE
MIXED
AIR
OUTSIDE AIR
RETURN AIR
EXHAUST AIR
STATIC PRESSURE SENSOR
& PICKUP TUBE
24 VAC
LOCAL COMM LOOP
SYSTEM MANAGER
NETWORK COMM LOOP
GROUND
FAN
SUPPLY AIR DUCT
HI LO
TEMPERATURE
SENSOR
RETURN AIR SENSOR
ZONE 1
TEMPERATURE SENSOR
CONTROLLER
ZONE
DAMPER
MODULATING
ZONE 2
TEMPERATURE SENSOR
UP TO 16 ZONES
BYPASS DAMPER
OUTSIDE AIR
SENSOR
AVOID
DIRECT
SUNLIGHT
2 CONDUCTOR
24 GA.
3 CONDUCTOR
24 GA.
2 CONDUCTOR
24 GA.
2 CONDUCTOR
24 GA.
COMM LINK II Remote Link
COMM LINK II
INTERFACE
( OPTIONAL )
120/24 VAC
TRANSFORMER 120/9 VAC
TRANSFORMER REMOTE LINK
(OPTIONAL MODEM)
COMPUTER
(OPTIONAL)
C O N T R O L S C O N T R O L S
1
4 2
5 3
6
9
8
0 7
Enter
Esc
* Minus
Menu
Clear Dec.
Alarm Communication Override
MANAGER SYSTEM
Auto-Zone CV 07/20/98 02:38PM MON OCCUPIED NO ALARMS
WATTMASTER CONTROLS INC.
First the zone must initiate a vote to the HVAC unit.
This occurs when a zone becomes more than 1 degree
off setpoint. At this time a vote is placed for heating or
cooling. Next the controller evaluates the total cooling
demand or heating demand within the entire building
to see which requirement is more critical. Finally, the
system looks for any priority conditions, which would
take precedence over other zones. All three of these
elements working together provide accurate and stable
control of comfort.
Additional control features are taken into account to
provide a very effective control of the system. Some of
these include priority override, supply air temperature
limits, outside air temperature lockouts, and min./max.
control over damper position.
Substantial savings can be realized using the Auto-Zone
Zoning system instead of having to install multiple roof-
top units to accommodate multiple zone requirements.
The Auto-Zone Zoning system is versatile and can be
used with any packaged roof top unit or split system. It
controls a variety of terminal unit functions including
single duct pressure dependent, pressure independent,
series fan and parallel fan terminals.
Figure 1-1: Auto-Zone Plus System Overview