Compressed air

• Install a control system to coordinate multiple air compressors.
• Study part-load characteristics and cycling costs to determine the most-efficient mode for
operating multiple air compressors.
• Avoid over sizing -- match the connected load.
• Load up modulation-controlled air compressors. (They use almost as much power at partial load as at full load.)
• Turn off the back-up air compressor until it is needed.
• Reduce air compressor discharge pressure to the lowest acceptable setting.
(Reduction of 1 kg/cm2 air pressure (8 kg/cm2 to 7 kg/cm2) would result in 9% input power
savings. This will also reduce compressed air leakage rates by 10%)
• Use the highest reasonable dryer dew point settings.
• Turn off refrigerated and heated air dryers when the air compressors are off.
• Use a control system to minimize heatless desiccant dryer purging.
• Minimize purges, leaks, excessive pressure drops, and condensation accumulation.
(Compressed air leak from 1 mm hole size at 7 kg/cm2 pressure would mean power loss equivalent to 0.5 kW)
• Use drain controls instead of continuous air bleeds through the drains.
• Consider engine-driven or steam-driven air compression to reduce electrical demand charges.
• Replace standard v-belts with high-efficiency flat belts as the old v-belts wear out.
• Use a small air compressor when major production load is off.
• Take air compressor intake air from the coolest (but not air conditioned) location.
(Every 50C reduction in intake air temperature would result in 1% reduction in compressor power consumption)
• Use an air-cooled aftercooler to heat building makeup air in winter.
• Be sure that heat exchangers are not fouled (e.g. -- with oil).
• Be sure that air/oil separators are not fouled.
• Monitor pressure drops across suction and discharge filters and clean or replace filters promptly upon alarm.
• Use a properly sized compressed air storage receiver.
Minimize disposal costs by using lubricant that is fully demulsible and an effective oil-water
separator.
• Consider alternatives to compressed air such as blowers for cooling, hydraulic rather than air
cylinders, electric rather than air actuators, and electronic rather than pneumatic controls.
• Use nozzles or venturi-type devices rather than blowing with open compressed air lines.
• Check for leaking drain valves on compressed air filter/regulator sets. Certain rubber-type valves may leak continuously after they age and crack.
• In dusty environments, control packaging lines with high-intensity photocell units instead of
standard units with continuous air purging of lenses and reflectors.
• Establish a compressed air efficiency-maintenance program. Start with an energy audit and followup, then make a compressed air efficiency-maintenance program a part of your continuous energy management program.