Air Energy Facts

Compressed Air Energy Facts

• Compressed Air is NOT free - it costs the equivalent of 50p/kWh.
• Leakage rates of 30% are common throughout industry.
• At 7 bar and 4.5p/kWh the annual kW use and cost, if the compressors are not switched off for:

Hole Diameter	Power Wasted	Cost per Year (8000 hrs)	CO2 Loss
0.4mm (pin prick)	800kW	£36	352kg
1.6mm (pin head)	8000kW	£360	3520kg
3.0mm (match head)	28000kW	£1260	12320kg

• A reduction of 4°c in compressor intake temperature increases the efficiency by 1%.
• Typically a kW of compressed air costs 10x that of the cost of electricity.
• Over a 10 year period the total cost of a compressor can be split:15% Capital Cost, 10% Maintenance Cost, 75% Energy Cost.
• 100kW (605cfm) running 24 hours per day, 7 days per week.
• Energy cost per year @5p/kWh is £40,000.
• The CCL will have increased this by £3,440 p.a
• Reducing the pressure by 1 bar will save approximately 4%.
• A 3bar compressor will generate air 33% cheaper than a comparable 7bar machine.

Energy Saving Techniques

• Match the compressor size to demand.
• Generate at the lowest acceptable pressure.
• Use waste heat from compressors for space or water heating.
• Check for leaks regularly and repair promptly.
• Zone the system and isolate pipework when not in use.
• Remove or shut off permanently unused pipework.
• Use solenoid valves to isolate machinery which is prone to leakage.
• Check pressure drops across filters and replace promptly when drops become excessive.