Honeywell AUTOMATIC CONTROL - Air Handling System Control Applications

ENGINEERING CMANUAL OF AUTOMATION CONTROL
AIR HANDLING SYSTEM CONTROL APPLICATIONS
201
Air Handling System
Control Applications
Contents
Introduction ............................................................................................................ 203
Abbreviations ............................................................................................................ 203
Requirements For Effective Control ............................................................................................................ 204
Applications-General ............................................................................................................ 206
Valve and Damper Selection ............................................................................................................ 207
Symbols ............................................................................................................ 208
Ventilation Control Processes ............................................................................................................ 209
Fan System Start-Stop Control ........................................................... 209
Fixed Quantity of Outdoor Air Control ................................................. 211
Outdoor Air Fan Control For Multiple AHU’s........................................ 212
Mixed Air Control ................................................................................. 213
Economizer Cycle Decision................................................................. 215
Economizer Cycle Decision—Outdoor Air Dry Bulb Control ............... 215
Economizer Cycle Decision—Outdoor Air Enthalpy Control ............... 216
Economizer Cycle Decision—Outdoor Air/Return Air
Enthalpy Comparison ....................................................................... 218
Economizer Cycle Decision—Outdoor Air/Return Air Dry
Bulb Temperature Comparison ........................................................ 219
Mixed Air Control With Economizer Cycle (Ventilation System Only) . 220
Economizer Cycle Control of Space Temperature With Supply Air
Temperature Setpoint Reset ............................................................ 222
Heating Control Processes ............................................................................................................ 223
Control From Supply Air ...................................................................... 223
Control From Space With Supply Temperature Reset ........................ 224
Outdoor Air Temperature Reset of Supply Air Temperature ................ 225
Space Temperature Control of Zone Mixing Dampers and
Reset of Hot Deck Temperature ....................................................... 226
Preheat Control Processes ............................................................................................................ 228
Preheat Control With Face and Bypass Dampers............................... 228
Control From Preheat Leaving Air ....................................................... 230
Multiple Coil Control From Outdoor and Supply Air............................. 231
Year-Round Heat Recovery Preheat System Control ......................... 233