Honeywell AUTOMATIC CONTROL SI Edition User Manual

ENGINEERING MANUAL OF AUTOMATIC CONTROL
INDOOR AIR QUALITY FUNDAMENTALS
166
FLOW TRACKING SYSTEM WITH MIXING
BOX STATIC PRESSURE CONTROL
Figure 5 is the same as the Flow Tracking System except for
the addition of a method of controlling the amount of outdoor
air. The outdoor air is controlled by maintaining a constant
negative static pressure in the mixed air. The pressure sensor is
referenced across the outdoor air damper which is maintained
at a variable minimum position until the economizer calls for
additional outdoor air. During non-economizer periods the EA/
RA dampers modulate to maintain static pressure constant at
the filter inlet. This is accomplished by separating the control
of the outdoor air damper from the control of the return and
relief dampers. Note that the OA damper minimum position
and the MA static pressure setpoint must be determined in
conjunction with the air balancing contractor. Refer to VAV
AHU WITH RETURN FAN AND FLOW TRACKING in the
Air Handling System Control Applications section.
Fig. 5. HVAC Flow Tracking with Differential Pressure Control of OA.
OA SA
RA
EA
RETURN FAN
M10487
F
F
SUPPLY FAN
CT
VSD
CT
VSD
RA FAN
STATUS
RA FAN
SPEED
RA
FAN
RA
TEMPER-
ATURE
RA FLOW
SIGNAL
OA
TEMPER-
ATURE
STATIC
PRESSURE
OA
DAMPER
RETURN
AND RELIEF
DAMPER
MA
TEMPER-
ATURE
HEATING
VALVE
COOLING
VALVE
SA
FAN
SA FAN
SPEED
SA FAN
STATUS
SA
TEMPER-
ATURE
SA FLOW
SIGNAL
SA
PRESSURE
ROOM
TEMPER-
ATURE
AFTER
HOURS

Honeywell AUTOMATIC CONTROL SI Edition Specifications

General

Brand	Honeywell
Model	AUTOMATIC CONTROL SI Edition
Category	Control Systems
Language	English