Effective design of the compressed air distribution system is essential to minimise electricity bills. The main design considerations should be to improve the efficiency of air usage at point of use, minimise leakage and the elimination over pressurisation which increases the leakage rate.
If the design of the distribution system is incorrect for the application then whichever compressors are used to generate compressed air, the system will never be able to achieve maximum efficiency. Typical problems include incorrectly sized pipe work which results in elevated compressed air generation pressure in order to overcome pressure drop across the system. The higher the generation pressure the higher the power costs and the more the system leaks.
Identifying and accurately maintaining the system target pressure, the minimum pressure required for efficient production machine operation, is a key element in avoiding over pressurisation. 1 barg reduction in system pressure saves 7.5% power consumption.
The lack of system capacitance, effectively inadequately sized receivers, leads to additional compressors operating for short periods of time when there is no real need to.
As the majority of compressed air leakage will occur within production equipment the system should be designed so that individual production machines and production areas can be isolated from the system when not in operation to eliminate leakage. Government figures hold that 25% of compressed air is wasted through leakage and incorrect pressure control and up to 50% is not uncommon.
The cost to operate a 75kw air compressor over 4000hr year at 0.1ppkwhr is £30,000. This means that you could be wasting £7-15,000 per year. A good analogy would be: Opening all the doors and windows in your house in the middle of winter then firing up your central heating system to heat the house. No matter how efficient your boiler is you'll still feel the cold!