Compressed air
Compressed air is expensive in energy terms.
Compressed air is often called the fourth utility, after electricity, gas and water. It is a valuable utility with many uses and it plays an important role in a number of industries.
Research shows businesses in New Zealand pay around $70 - 100 million a year for electricity to produce the compressed air they need. [1] However they get a poor energy return of only around 10% to 15%. Losing 85% to 90% of the energy makes compressed air probably the most expensive utility per unit of work. This makes it a good place to start looking for worthwhile energy savings.
You can improve the energy efficiency of your air compressor by:
- Repairing leaks -a small air leak (3mm) could cost you $700 a year. A hole the size of an old 5 cent piece could cost $30,800 a year (based on 7 bar pressure, operating 40 hours per week)
- Shutting down compressors when not in use
- Checking filters and dryers regularly
- Having a maintenance programme
- Maintaining lubricators to reduce friction and wear
- Maintaining monitoring and control equipment
- Reducing hoses and couplings - thus reducing the chance of leakage
- Installing flow regulators and pressure valves
- Fitting timers to compressors with pneumatic unloaders so they only operate when they're loaded
- Making sure intercoolers are accurately sized (by measuring temperatures) and kept clean.
More information
Switch Off, Better Off - EECA provides stickers and posters for you to use in reminding staff to turn off un-needed lights, appliances, machinery and vehicles.
Notes
[1] Efficiency and Conservation Authority (EECA) and the Foundation for Research, Science and Technology (FRST) Managing the Fourth Utility 2007 (online)
