FanCycling: Fan is cycled on and off to control duty.
TwoSpeedFan: Fan is switched between low and high speed to control duty.
VariableSpeedFan: Fan speed is varied to control duty.
DampersControl: Dampers modulate the air flow to control duty.
BypassValveControl: Bypass valve modulates the water flow to control duty.
MultipleSeriesPumps: Turn on/off multiple series pump to control duty.
TwoSpeedPump: Switch between high/low pump speed to control duty.
VariableSpeedPump: vary pump speed to control duty.