Vav Ahu, Water-Side Economizer, Oa Airflow Control - Honeywell AUTOMATIC CONTROL SI Edition Engineering Manual

VAV AHU, WATER-SIDE ECONOMIZER, OA AIRFLOW CONTROL

Functional Description
WARM-UP MODE INVOLVED AT OPTIMUM
START TIME IF PERIMETER SPACE
TEMPERATURE IS LESS THAN
WARM-UP ENDS WHEN RETURN
23.5
AIR REACHES
24
0.45
8
83
OA
9
CFM
2306
19
16.5
2300
10
ANYTIME ALL VAV BOX DAMPERS ARE LESS THAN 90% OPEN, DECREMENT THE AHU
DUCT STATIC PRESSURE SETPOINT
ANYTIME ANY VAV BOX DAMPER IS FULL OPEN, INCREMENT THE AHU DUCT STATIC
PRESSURE SETPOINT
Item
No. Function
1-3 Control system energizes when supply fan is
turned on (See FAN SYSTEM START-STOP
CONTROL).
4-6 Supply fan loads to maintain duct static
pressure.
7-10 During occupied periods, exhaust fan runs and
OA airflow is controlled.
11-14 When perimeter temperature is low at startup,
SA temperature setpoint is warm until RA
temperature rises.
ENGINEERING MANUAL OF AUTOMATIC CONTROL
14
21
.
.
RA
13
11
25
TEMPERATURE SETPOINT
22
20
NORMAL
16
00
kPa EVERY
0.025
4.0
kPa EVERY
0.025
AIR HANDLING SYSTEM CONTROL APPLICATIONS
PERIMETER
21
ZONE
WARM-UP
23.5
MODE
ON OFF
SPACE
32 13
17
SUPPLY AIR
2
1
ON
63
PERCENT
4
LOAD
18
76
22
CONTROL
PROGRAM
23
4.0
MINUTES.
MINUTES.
15-16 Heating valve maintains SA temperature
setpoint during warmup.
17-18 Cooling valve maintains SA temperature
setpoint during occupied periods.
19-20 OA and MA temperatures are operator
information.
21 SA temperature setpoint switches from cooling
to heating value during warm-up modes.
22 Control program coordinates temperature
control, ventilation, and fan interlock.
255
PROPELLER
EXHAUST
FAN
12
ON
3
NORMAL
SA TO VAV
BOXES
0.45
13.5
15
6
0.45
MAXIMUM
SETPOINT
7
5
M15181