The changing face of compressed air specification

With increasing legislation around mandatory carbon reporting and volatility in energy prices, the issue of energy efficiency has become a top priority for manufacturers. Not all businesses however are aware of the impact that their compressors can have on their energy bills and carbon emissions and equally the importance of correctly sizing equipment. 

A common misconception, even now, is that compressed air is ‘free’ once the equipment has been purchased.

Yet in reality, the electricity consumed during operation over a five-year period accounts for around 75% of the total cost of ownership, including the initial capital outlay for the compressor. A further consideration that we are often presented with is companies replacing equipment like-for-like, but this doesn’t necessarily mean the new compressor will be right for the application.

For example you could have two compressors with the same size motor but completely different outputs. So it is important for end users to consider the specific energy efficiency of different compressors, i.e. the amount of energy required to generate one cubic metre of air per minute. Even a small difference in this figure, often stated as kW/m³/min, can make a significant difference in the annual running costs of a compressor and the larger the compressor and the higher the running hours, the more important it is.  

Significant advancements have been made in compressor technology, over recent years, meaning that if an ageing machine is replaced with a modern equivalent then – providing it is sized correctly and is appropriate for the end user’s production processes – energy and carbon savings should theoretically be achieved. 

Needless to say however, a detailed analysis of the site and its requirement is essential and end users should involve a compressor specialist from the very start to ensure the most cost effective and energy efficient solution. 

To reiterate this point, we are currently seeing an increase in requests for ‘oil-free’ air – but without any reference to ISO8573-1:2010. This requires BCAS (British Compressed Air Society) – and us as BCAS members – to proactively explain to end users and specifying engineers the importance of correctly specifying the air quality in accordance with this standard to meet their actual needs. It must be remembered that simply saying ‘oil free’ doesn’t mean anything, and specifying a standard that is far higher than really required will add unnecessary and, in many cases, considerable cost to the initial capital outlay and the on-going running costs.

One interesting element that we hope will help end users is the launch of ISO 11011 which will aim to encourage assessment of compressed air systems. Energy audits, carried out in line with ISO 11011, will not only show consumption patterns but also recommend actions for businesses to take to help reduce consumption. Although it is a voluntary scheme, it is hoped that compressed air users will see the value of ISO 11011 and adopt it as best practice.

The specification of a new compressor presents an ideal opportunity to improve energy efficiency within a business, but only when properly considered and correctly suited for the application. Seeking the advice of a specialist and investing in a full site assessment before making a purchasing decision is a wise move and we can only hope that end users will follow our advice. 

As a BCAS member, Mattei continues to promote to the end user the importance of working with reputable compressed air companies, and we always point people towards the BCAS AirSAFE register to help source their service provider.