Dictionary
Compressed Air Energy Audit Dictionary
Compressor Types
| Term | Definition |
|---|---|
| Rotary Screw Compressor | Uses two intermeshing helical rotors to continuously compress air; ideal for industrial continuous-duty operation. |
| Reciprocating Compressor | Uses piston-cylinder mechanism; suitable for intermittent or small-scale applications. |
| Oil-Injected Compressor | Oil is injected into compression chamber for cooling, sealing, and lubrication. |
| Oil-Free Compressor | Compresses air without oil contamination; essential for food, pharma, and electronics industries. |
| Two-Stage Compressor | Compresses air in two stages for improved efficiency at higher pressures. |
| Variable Speed Drive (VSD) | Adjusts motor speed based on air demand to reduce energy consumption. |
| Fixed Speed Compressor | Operates at constant motor speed; less flexible under variable load conditions. |
Key Compressor Components
| Component | Function |
|---|---|
| Air End | Core compression unit in rotary screw compressor. |
| Electric Motor | Drives the compressor air end. |
| Inlet Valve | Controls air intake. |
| Oil Separator | Removes oil from compressed air before discharge. |
| Oil Filter | Filters contaminants from lubricating oil. |
| Air Filter | Prevents dust and debris from entering system. |
| Aftercooler | Reduces compressed air temperature and moisture. |
| Cooling Fan | Maintains safe operating temperature. |
| Thermostatic Valve | Regulates oil temperature. |
| Check Valve | Prevents reverse airflow. |
| Minimum Pressure Valve (MPV) | Maintains internal system pressure stability. |
| Drain Valve | Removes condensate from system. |
| PLC / HMI | Control and monitoring interface. |
| Safety Valve | Protects system from overpressure damage. |
Performance & Energy Terms (Important for Audit)
| Term | Meaning |
|---|---|
| Free Air Delivery (FAD) | Actual air output under standardized conditions. |
| Specific Power | kW consumed per m³/min (or CFM) produced; key efficiency indicator. |
| kW Demand | Electrical power consumed by compressor. |
| Duty Cycle | Percentage of time compressor operates under load. |
| Pressure Drop | Loss of pressure due to friction or restriction in piping. |
| Leakage Rate | Percentage of air lost due to leaks. |
| Artificial Demand | Extra air usage caused by excessive system pressure. |
| Energy Intensity | Energy consumed per unit of air delivered. |
| ROI (Return on Investment) | Financial return from energy-saving improvements. |
| Payback Period | Time required to recover investment cost. |
Compressed Air Audit Terms
| Term | Definition |
|---|---|
| Air Audit | Systematic assessment of compressed air system performance and energy losses. |
| Data Logging | Recording pressure, flow, and power over time. |
| Baseline Profile | Standard operating performance benchmark. |
| Demand Profile | Air consumption pattern over time. |
| Peak Demand | Highest recorded air usage during audit period. |
| Load Profile | Compressor loading behavior over defined intervals. |
Compressed Air Quality Terms
| Term | Definition |
|---|---|
| ISO 8573-1 | International standard defining compressed air purity classes. |
| Dew Point | Temperature at which moisture condenses. |
| Pressure Dew Point (PDP) | Dew point measured at operating pressure. |
| Refrigerated Dryer | Removes moisture using cooling method. |
| Desiccant Dryer | Removes moisture using adsorption material. |
| Coalescing Filter | Removes oil aerosols and fine mist. |
| Activated Carbon Filter | Removes oil vapors and odors. |
| Water Separator | Separates bulk liquid water from air. |
System & Distribution Components
| Term | Function |
|---|---|
| Air Receiver (Tank) | Stores compressed air and stabilizes pressure. |
| Ring Main | Closed-loop piping system for balanced air delivery. |
| Distribution Piping | Network delivering air to end-use equipment. |
| Flow Controller | Regulates downstream air volume. |
| Pressure Regulator | Maintains consistent outlet pressure. |
| Drop Leg | Vertical pipe section for moisture drainage. |
Safety & Compliance
| Term | Meaning |
|---|---|
| Pressure Relief Valve (PRV) | Releases air when pressure exceeds safe limit. |
| Emergency Stop (E-Stop) | Immediate shutdown mechanism. |
| Lockout-Tagout (LOTO) | Safety procedure for maintenance isolation. |
| ATEX Certification | Certification for equipment in explosive environments. |
| Overheat Shutdown | Automatic shutdown due to high temperature. |
Typical Maintenance Intervals
| Service Item | Typical Interval |
|---|---|
| Air Filter | 2,000 – 4,000 hours |
| Oil Filter | 2,000 – 4,000 hours |
| Oil Separator | 4,000 – 8,000 hours |
| Lubricant (Mineral) | 2,000 – 4,000 hours |
| Lubricant (Synthetic) | 4,000 – 8,000+ hours |
| Leak Survey | Annually or quarterly |