The cost of using an air compressor

Air-powered tools have a number of advantages. One significant but surprisingly often neglected disadvantage is the cost. Air is frequently regarded as “free”, but running an air compressor can often be highly expensive. In this article we look at some of the costs involved in using air compressors and the inefficiencies of using air-powered equipment.

First, a simple question to get us thinking about this topic. What proportion of industrial power consumption in a country or region is due to compressed air? You’re probably thinking of quite a small figure. 3%? 2%? Less than 1%? The answer may surprise you.

The energy consumption in Europe of pneumatic systems accounts for around 10% of total industrial power consumption. It’s a similar story in the US and China, where pneumatic systems consume around 9% of the whole electricity consumption.

What’s more, the efficiency of pneumatic systems is poor – coming in at around only 30% - due to improper use, poor management, and low efficiency of pneumatic components. It's no surprise that the U.S. Department of Energy has stated that compressed air systems are often the least efficient source of energy in a plant; often the biggest end use of a plant’s electricity; and are frequently used inappropriately.

To put these figures into perspective, to operate a 1 HP compressed air motor, approximately 7 HP of electrical power is required. This ratio is even higher when the pressure is higher than a typical pressure of 90 psi. This figure can be corroborated by calculating the energy savings for a potential switch from pneumatic to electric tools.

The annual electricity needed to supply compressed air to a 0.5 HP pneumatic tool consuming an average of 20.7 cfm of air is 1320 kWh/year. If the same calculation is performed on an equivalent corded electric tool, the electricity needed is 230 kWh/year. In other words, the annual electrical energy savings associated with replacing a pneumatic tool with an electrical tool is 1320 – 230 kWh/year = 1090 kWh/year. If the average power cost is $0.10/kWh, the annual savings would be $109 per tool.

If you are running a number of air-powered tools, you can thus understand that changing to electric-powered tools can save you a significant amount of money each year.

This is one of the reasons behind the popularity of Graco’s KING range of electric sprayers. Any Electric KING unit is up to eight times more efficient than a comparable air-driven unit. The bottom line is that a KING electric sprayer will consume only one-eighth of the electricity needed by an equivalent air-powered unit. That’s a significant reduction in your electricity bill.