Compressors: the importance of siting

Significant energy and carbon savings can be achieved by investing in a new, modern compressor. In fact, we have many examples we can cite where manufacturers have achieved substantial savings through updating their compressors; for many of our customers the savings have been in the region of £20,000 to £30,000 per year and considerably more in some cases.  

However, for energy and carbon savings to be achieved, the new compressor/s must be appropriately sited, and the pipework must be in good condition with the layout designed to maximise efficiency and performance.  

In terms of siting, the environmental conditions around the compressor – including air flow, pollutants and heat – need to be assessed. 

Some compressors are installed in purpose-built plant rooms, but these are not always as ideal as you might think. To maximise efficiency, the air flow to a compressor should be unrestricted, but some compressor houses have just a small air vent, which might not provide sufficient air flow around the compressor. On some sites the door to the compressor house is left open to try and resolve this – but this might still not provide suitable air flow, and could actually lead to pollutants being drawn into the air intake filter, blocking it prematurely. 

It’s equally common to find compressors sited on a factory floor, where again environmental factors, such as fibres from production processes or materials stored around the compressor, can affect air flow, and hence efficiency. 

The air going into a compressor needs to be reasonably clean and free from solid and gaseous impurities. In some cases this can be relatively straightforward – sometimes simply rotating a compressor can be enough to dramatically reduce any dust particles entering the machine and blocking the intake filter. If relocating the compressor isn’t feasible then additional filtration can be used to remove impurities.  

Heat should be another consideration. Cooler air is denser and makes the compression process more efficient, so if the air being drawn into the compressor is warm the machine will have to work harder, reducing its efficiency as well as the lifetime of its parts.  It’s therefore important to avoid installing a compressor near heat-generating equipment like boilers, furnaces or ovens.

Pipework

In addition to assessing these environmental factors, the condition and layout of existing pipework should be evaluated. Unfortunately this doesn’t always happen when a new compressor is installed – and if alterations aren’t made, energy efficiency savings could be negated, making the investment a false economy. 

If the pipework is showing signs of damage, such as rust and corrosion, we would recommend an upgrade. It is also essential to check for leaks in the pipework. As a guide, for a company using 50m³ of compressed air per minute we estimate the annual savings from fixing leaks could potentially be in the region of £63,000. 

In terms of pipework layout, excessive lengths and bends lower efficiency, so pipe runs need to be suitably designed. For systems where the point of use and the compressor are relatively close then a single line could be chosen, whereas for larger systems with many points of use then a ring main would be preferable. It’s also important to remember that although smaller diameter pipe may save on capital cost, greater pressure drops in the system will lead to a higher operating cost. 

While new, correctly specified compressors can lower running costs and carbon emissions, in order to achieve optimum energy savings they need to be sited correctly and the pipework must be in good condition with a suitably designed layout.