Honeywell Design and Application - Example 3: Minimum Ventilation Adjustment

Section 1 - Ventilation
Honeywell Economizers 63-8594-02 16
Example 3: Minimum Ventilation Adjustment
1. Specifications:
Office space - 100,000 ft
2
Air handler capacity 20,000 cfm
(566 m
3
/min.)
People in area - 250
2. Ventilation (V
OT
) required:
= 250 x 5 cfm + 0.06 cfm/ft
2
x 100,000 ft
2
= 1250 cfm + 6000 cfm
= 7250 cfm
Where V
at
= 0.06 cfm/ft
2
x 100,000 ft
2
.
Therefore V
at
= 6000 cfm
3. Ventilation percentage:
7250 cfm (205.3 m
3
/min)/20,000 cfm
(570 m
3
/min)
V
OT
maximum position= 36%
6000 cfm (169.9 m
3
/min)/20,000 cfm
(570 m
3
/min)
V
OT
Minimum position= 30%
4. Measure the return air temperature:
73°F (23°C).
5. Measure the outside air temperature:
30°F (-1°C).
This example shows a procedure for adjusting
the DCV maximum and minimum positions.
OUTSIDE
A
IR
30˚F (-1 C)
EXHAUST
AIR
DAMPER
M23910
DAMPER
RETURN
AIR
73˚F (23 C)