Honeywell AUTOMATIC CONTROL User Manual

ENGINEERING MANUAL OF AUTOMATION CONTROL
BUILDING AIRFLOW SYSTEM CONTROL APPLICATIONS
270
∆P=Differential static pressure across the door
in inches of water column (in. wc)
F = F
DA
+
Kd x W x A x ∆p
2 x (W – D)
RETURN
AIR FAN
OUTDOOR
RELIEF (OR)
EA
RA
OA
35,000 CFM
CONSTANT
COOLING
COIL
FILTER
OUTDOOR AIR
5,000 CFM
MINIMUM
40,000 CFM
CONSTANT
REMOTE
EXHAUST FAN
2,000 CFM
TT
INTERIOR ZONES
T
TTT
T
T
REHEAT
COILS
PERIMETER
ZONES
C2663
EXFILTRATION
3,000 CFM
CAV AIR
TERMINAL
UNITS
T
SUPPLY
AIR FAN
T
Fig. 2. Single Duct Constant Air Volume System.
PRESSURIZATION
Building pressurization and ventilation are important aspects
of airflow control. A building or areas within a building can be
pressurized for positive, negative, or sometimes neutral static
pressure to control the flow of air from one area to another. A
building can use positive static pressure to eliminate infiltration
drafts, possible dirt, and contamination from outside sources.
Areas within a building such as laboratories can use negative
pressure to prevent contamination and exfiltration to adjacent
spaces and zones. Proper building pressurization must also
consider the effects of outdoor wind pressure and stack effect
or vertical air differences.
BUILDING PRESSURE BALANCE
The pressures in a building must be balanced to avoid airflow
conditions which make it difficult to open and close doors or
conditions which cause drafts. Buildings have allowable
maximum and minimum static pressures that control these
conditions. A force of 30 through 50 pounds is considered the
maximum reasonable force to open a door. The equation used
to calculate the force to overcome the pressure difference across
a door as well as to overcome the door closer is as follows:
Where:
F=Total door opening force applied at the knob
in pounds (lb)
F
DA
=Force to overcome the door closer, applied at
the knob, in pounds (lb). This force is
normally between 3 and 20 lb.
Kd = A coefficient, 5.20
W=Door width in feet (ft)
A=Door area in square feet (ft
2
)
D=Distance from the door knob to the knob
side of the door in feet (ft)

Honeywell AUTOMATIC CONTROL Specifications

General

Brand	Honeywell
Model	AUTOMATIC CONTROL
Category	Controller
Language	English