ENGINEERING MANUAL OF AUTOMATIC CONTROL
AIR HANDLING SYSTEM CONTROL APPLICATIONS
254
For heating conditions it is assumed that:
1. Design outdoor air condition is –18°C DB and 30 percent
relative humidity.
2. RA condition is 24.5°C DB and 13.5°C WB.
3. System operates on 25 percent minimum outdoor air.
4. Space temperature is set at 23.5°C.
5. Space humidification control is set at 50 percent.
The following results are obtained:
Item
No. Explanation
1 Heating coil leaving air temperature will be as
high as required to satisfy the space
temperature controller.
2 Humidification will be provided to satisfy
space humidification requirements.
3 The space heating and humidifying load
varies with people and weather.
4 The 1 kelvin DB RA rise is discussed in the
cooling example.
C3264
MA
HEATING
RA 24°C DB, 17°C WB
HEATING COIL
DISCHARGE
1
2
3
4
OA
-18°C DB
30% RH
SPACE
23.5°C DB
HUMIDIFIER
DISCHARGE
1 KELVIN