Compressed air is one of the largest consumers of energy. It’s time to think about costs with energy prices not looking to decrease anytime soon. Your compressor becomes no.1 suspect for the big bill landing on your desk at the end of each month!

An obvious suggestion is to turn off your compressor when it is not in use. But what do you do when you run a three-shift system in a 24/7 production facility?

Read our 5 tips to reduce the running costs of your compressed system without altering schedules. Let’s make the fourth utility more affordable.

 

1. Reduce the pressure

In many systems the pressure is set to a higher level than actually needed. This uses more energy to compress the air to reach the needless high pressure. The result is large volumes of wasted compressed air. For every extra 2 psi, energy costs increase by 1% – which soon adds up!

If you’re increasing the pressure to operate many end uses, can you use a separate compressor? This allows the system to operate at a reduced pressure, decreasing energy consumption.

2. Fix air leaks

If the compressed air system is more than 12 months old, it will have some leaks. The leaks could be in the pipework, fittings or the point of use equipment. Even a small leak, one that is too small to hear with the naked ear, will be wasting energy and costing you money.

Leak noise level (dB)Similar noise level toLeak size (cfm @100psi)Estimated cost per houe
10Normal breathing0.5£0.01
20Mosquito0.7£0.01
30Whisper1.3£0.03
40Domestic fridge1.5£0.03
50Quiet office2.4£0.05

On average a small compressed air system will have between 10 and 30 separate leaks.

To fix a leak, you need to identify it. Ultrasonic testers listen to air leaks, allowing you to repair any significant leaks. Begin the pay-back period of the test – don’t let leaks go unfixed!

 

3. Track air usage

You can’t put in place cost saving initiatives until you know what’s happening in your system. Investing in equipment to measure pressure, volume flow and leaks has cost-savings benefits.

  • Highlights savings potential
  • Reduce the escape of expensive compressed air
  • Assign costs to individual production processes
  • Prevent possible breakdowns by alerting you to any changes

4. Use the heat generated by your compressor

Approximately 80% of the energy created during the compression process is given off as heat. This heat is usually given off into the atmosphere and wasted.

For example, an 11Kw compressor has the potential to lose up to 9Kw in heat energy!

Use the heat by-product from compression to save costs elsewhere. Redirect this energy, for example into ducting to heat the building. Or you can retrofit a heat exchanger to an air compressor cooling system to pre-heat water.

Telford Yarns were able to take advantage of a heat recovery solution. They achieved £7,000 in energy savings per year and a rise of 6 degrees in temperature.

 

5. Select the right compressor

It is important to invest in the right compressor when replacing equipment or buying new.

Research the best technology which fits your application, pressure and capacity needs. But you can also consider what suits your energy savings strategy.

Fixed speed compressors produce a fixed amount of compressed air per minute. The design ‘runs on’ in an ‘unloaded’ condition after the air pressure has been reached. It’s very rare that the amount of compressed air generated matches the need exactly. So the compressor will be frequently turning over. In an unloaded condition, the air compressor is still using between 25% and 50% of the energy it is using when creating compressed air.

Variable speed compressors rotate more slowly, produce less air and absorb less energy. The air compressor slows its rotation speed to produce exactly the amount of compressed air used by the downstream equipment. This means it doesn’t have to run unloaded and saves significant amounts of energy.

On average a variable speed compressor will save 30% of the energy used by a fixed speed, especially when not running permanently at full load.

There are many cost-saving practices you can build into your business plan and maintenance schedule. The larger your compressed air system, the greater the opportunity for cutting costs can be.