ACR Journal

CMYK / .ai CMYK / .ai CMYK / .ai acrjournal.uk 15 EFFICIENCY Figure 2 – Comparison of site SEC with other facilities store volume is 75,000 m3 so the SEC is 25 kWh m-3 a-1. Tracking this value over time will show whether energy performance is improving or worsening so it can be a useful guide to the operational integrity of the site. In this case the store can be seen to be performing better than would have been expected in 1994 but indications are that there is still room for improvement compared with modern best practice, which would only require half of the electrical input to maintain store temperature. With a bit more e ort it is also possible to create a comparison between di erent sites, and this is where the store volume becomes particularly important. The shape of the best practice curve indicates that there is an economy of scale at work: a store that is twice the size should not need twice the electrical input because the heat gains through the surface will not be double. A logistics company with multiple sites can plot their own estate on a common graph and produce a means of comparing facilities. There is also a role for a third party data collector to provide a comparison service to provide a broader view of performance. In this arrangement all users submit their energy information to a central hub and the results are shared between all participants, but in an anonymised form. This is shown in Figure 2 where the facility from Figure 1 can now be compared with thirty other data points in facilities ranging from one third of the size to five times larger. It is important to realise that some of the features that contribute to best practice performance might not be feasible in all cases. For example old insulation may be somewhat degraded compared to a new facility or equipment may be a bit worn, but the study showed that deviation from best practice was generally caused by three factors. Deterioration in infrastructure (or structure that was poorer to start with) is a fact of life and di cult to change without significant investment. Worn out equipment can be overhauled or replaced to achieve an improvement at relatively low cost. Some best practice activity, such as maintaining tighter control of goods new facility or equipment may be a bit worn, but the study showed that deviation from best practice was generally caused by three factors. Deterioration in infrastructure (or structure that was poorer to start with) is a fact of life and difficult to change without significant investment. Worn out equipment can be overhauled or replaced to achieve an improvement at relatively low cost. Some best practice activity, such as maintaining tighter control of goods incoming temperature or managing door openings more carefully require behaviour change, perhaps with no capital investment. That doesn’t mean that it is easy; changing operating habits is sometimes very difficult, but it is possible withou high investment cost. An interesting cons qu nce of his understanding of the factors that make a facility “best practice” is that the bes practice met i is n t heavily dependent on the location of the site or the weather. <caption> Figure 2 – Comparison of site SEC with other facilities