AUTOMATIC HVAC control systems are designed to maintain temperature@ humidity@ pressure@ energy use@ power@ lighting levels@ and safe levels of indoor contaminants. Automatic control primarily modulates@ stages@ or sequences mechanical and electrical equipment to satisfy load requirements@ provide safe equipment operation@ and maintain safe building contaminant levels. Automatic control systems can use digital@ pneumatic@ mechanical@ electrical@ and electric control devices. Human intervention is not limited to scheduling equipment operation and adjusting control set points; it can also include tracking trends and programming control logic algorithms to fulfill building needs.