## Energy Conservation- Minimizing compressed air losses

To minimize compressed air losses in environments in which line are prone to leakages, reduce the air compressor discharge pressure to the lowest acceptable pressure.

The Air compressor system is normally set to run between 100 PSI - 125 PSI (7 to 9 bar) in the industrial plant. However, most of the equipments don’t require a pressure that is much lower than this range. Thus the pressure of the air in the compressor can be reduced to a pressure just sufficient to meet the pressure requirements at the user end.

Especially in plants with environments where compressed air lines are prone to leakages which cannot be immediately repaired, such as in corrosive environments, continuous running plants, or plants with long distribution lines; reducing the generation pressure will also reduce the leakage loss. This is because the compressed air loss through a leakage of a given size increases proportionately with the pressure of the compressed air.

Thus, reducing the air compressor discharge pressure to the lowest acceptable pressure will minimize the compressed air leakage losses.

Consider a 1000 scfm compressor which requires a 220 KWH Motor i.e. the 220 KWH motor generates 1000 x 60 =60000 Std. cu. ft of air per hour.Thus 1 KW of electricity generates 273 std. cubic feet of

compressed air.

Considering the power cost of 1 KWH is Rs. 5.00, the power cost of 1 cu. Ft.  becomes 2 paise or 0.02 Rupees. Thus, the running cost for a 1000 Scfm Compressor, at 80% load, becomes:

1000 x 60 x 0.8 x 0.02 x 24 = Rs. 23,000 per day, o Rs.75 Lacs p.a.

Consider a leak of 1.6mm (1/16”) diameter in a compressed air line with pressure of 7bar. Thus, considering the above setup, the monetary loss through this leak would be Rs.28,800 per year. However, if the pressure in the same line has been 5bar, the annual monetary loss would be Rs.20,600 per year i.e. a 28.5% saving over the previous case!