Energy and compressed air Q&A

With compressed air accounting for about 10% of the global energy used in industry today, it is vital that businesses recognise the benefits of investing in the right compressed air equipment. And just because a compressor can run trouble-free for years, doesn’t necessarily mean it is operating at maximum efficiency. In this Q&A, Colin Mander, director of industrial sales with CompAir UK and Ireland, answers some of the common questions surrounding energy efficiency and compressed air: Q: Although many businesses would like to minimise their environmental burden, their first concern will always be the bottom line. What tangible benefits does energy efficiency offer? A: Saving energy isn’t just a ‘green’ issue – it makes real business sense. In the face of high and volatile fuel costs and increasing uncertainty around the future price of energy, organisations must look at energy efficiency as a way of reducing costs. Improving energy efficiency will reduce fuel consumption, cut costs, and have a direct effect on profits. Reducing the spend on energy directly lowers production costs, which in turn allows the business to offer products and services at lower prices, or make further profit. Also, with climate change rising up the political agenda, further government regulations, along the lines of the existing Climate Change Levy and Emissions Trading Scheme, are likely to be introduced. By tackling energy efficiency now, businesses can be prepared in advance for any changes to legislation. Q. How can companies make improvements? Companies can often make improvements throughout their business from energy efficient lighting and efficient heating, to the efficiency of their compressed air usage. In all of these, an analysis of the real needs is required. To thoroughly analyse the compressed air system, data logging needs to be carried out. Information obtained from the exercise, allows companies to see their air usage presented graphically, typically over a seven-day period. Comparing this to various options of compressed air system allows decisions to be made to optimise energy usage. This may result in further action such as upgrading equipment or re-configuring the compressed air system to better match demand with supply. Q: How does data logging work? A: Data logging assesses the efficiency of the air system to establish how much energy the compressor is using and what the company’s real compressed air requirements are. For example, the CompAir SmartACE intelligent data logger is connected to the compressor in a non-intrusive process that does not interfere with normal running. The gathered data can be reviewed on a laptop to show patterns of air demand and identifies the energy savings that could be achieved with different compressor configurations. If a customer is considering a number of alternative options, the exercise provides comparisons for a more informed purchasing decision and provides an indication of the energy savings that can be achieved. Q. What factors contribute to a system’s efficiency? A. The data provided from the data logger helps businesses ascertain the optimum system for their needs. This includes compressor configuration, individual compressor control modes, the number of compressors needed to meet the demand, overall system control, pressure drops through air treatment equipment and sizing of the piping systems, all of which can help improve the efficiency of the compressed air system. These can be matched to air demand fluctuations, for example, when processing equipment cuts in or out throughout a shift. The analysis can take into account changes in the business set up, expansion plans and resources available. Q: Surely a reliable compressed air system means it is working efficiently and effectively? A: Reliability is not the only factor to consider when assessing a compressed air system. A user may have a perfectly reliable compressor, but this can still be costing them unnecessary money in terms of wasted energy. With compressed air accounting for about 10% of the global energy used in industry today, it is vital that businesses recognise the benefits of investing in the right compressed air equipment. Compressor technology has progressed in the last few years to offer even greater efficiency. Replacing out-of-date compressors can dramatically lower energy consumption, save thousands of pounds in fuel costs each year and reduce the amount of CO2 emissions going into the atmosphere. Q: Can the location of the compressor make a difference to its efficiency? A: The further away a compressor sits from the point of use, the more pipework that is needed which can leave it vulnerable to leaks and pressure loss. By positioning the compressor closer to where the air is required, these issues can become less of a consideration. Compressors have previously been considered too noisy to locate on the factory floor and common practice has been to house them in plant rooms. To overcome this issue, new machines have been designed with a smaller footprint and reduced noise level. For example, the new L50 has a noise level of just 67dB(A), well below the typical factory noise levels of 80-90dB(A). This means it is easy to stand next to the compressor and have a conversation and there is no need for users to wear ear protection. Coupled with the smaller footprint, the compressor does not need to be relegated to a distant compressor house, but can be located right next to the point of use of the air. Q: How can the energy efficiency of a compressor be improved? A: For a compressor to operate at optimum energy efficiency, it is necessary to match the supply from the compressor with the demand for air. Variable speed drives precisely match air demand with power consumption – eliminating energy loss during periods of unloaded running. Using variable speed instead of fixed speed compressors can produce savings in excess of 25% in energy and operational costs. The compressors are able to accurately maintain a set pressure while responding instantly to changes in air demand. Maintaining air system pressure at an exact pre-set level eliminates the need to operate within pressure bands, further enhancing energy performance by reducing electrical and mechanical loads. A further operational advantage where demand on the site’s power supply is particularly high, is the fact that the speed regulated compressors are able to start without increasing supply current above normal running levels. This reduces stress on the site’s power supply and eliminates peak current energy cost penalties. It is not always necessary to replace a compressor to achieve greater energy efficiency. The majority of air compressors operate at an average of just 50 - 70% of full capacity, and it is at these levels that variable speed compressors achieve their energy savings. Q: Are there any initiatives that exist that will encourage companies to make improvements? A: There are various financial incentive schemes available for businesses adopting energy efficient processes and equipment. Government funded interest-free loans are available via the Carbon Trust’s energy efficiency programme, providing organisations with funds to buy and install energy-saving equipment such as compressors – allowing businesses to upgrade their equipment before their own budgets allow, in order to reduce their energy bills immediately. The Enhanced Capital Allowance (ECA) scheme encourages businesses to invest in energy saving technologies and products in order to reduce carbon emissions. The scheme allows businesses to claim 100% first year capital allowances on such investments, writing off the whole cost against taxable profits during the investment period. Many of CompAir’s variable speed products qualify for the allowance. Purchasing products included on the ETL should result in significant long-term financial savings by reducing energy bills and CCL payments, and also tax relief, which can deliver a cash flow boost and shorten the payback period on investments.