Engineering Manual o.. - HVAC.Amickracing

CONTROL FUNDAMENTALSControl FundamentalsENGINEERING MANUAL OF AUTOMATIC CONTROLCONTENTSIntroduction ............................................................................................................ 5Definitions ............................................................................................................ 5HVAC System Characteristics ............................................................................................................ 8General................................................................................................ 8Heating ................................................................................................ 9General ........................................................................................... 9Heating Equipment ......................................................................... 10Cooling ................................................................................................ 11General ........................................................................................... 11Cooling Equipment .......................................................................... 12Dehumidification .................................................................................. 12Humidification ...................................................................................... 13Ventilation ............................................................................................ 13Filtration ............................................................................................... 14Control System Characteristics ............................................................................................................ 15Controlled Variables ............................................................................ 15Control Loop ........................................................................................ 15Control Methods .................................................................................. 16General ........................................................................................... 16Analog and Digital Control .............................................................. 16Control Modes ..................................................................................... 17Two-Position Control ....................................................................... 17General ....................................................................................... 17Basic Two-Position Control ......................................................... 17Timed Two-Position Control ........................................................ 18Step Control .................................................................................... 19Floating Control ............................................................................... 20Proportional Control ........................................................................ 21General ....................................................................................... 21Compensation Control ................................................................ 22Proportional-Integral (PI) Control .................................................... 23Proportional-Integral-Derivative (PID) Control ................................ 25Enhanced Proportional-Integral-Derivative (EPID) Control ............. 25Adaptive Control.............................................................................. 26Process Characteristics....................................................................... 26Load ................................................................................................ 26Lag .................................................................................................. 27General ....................................................................................... 27Measurement Lag ....................................................................... 27Capacitance ................................................................................ 28Resistance .................................................................................. 29Dead Time .................................................................................. 29Control Application Guidelines ............................................................ 29ENGINEERING MANUAL OF AUTOMATIC CONTROL3