Improving Energy Efficiency in Legacy Building Systems

Session 3, Case Study 4, CIBSE ASHRAE Technical Symposium, Dublin, Ireland, 3-4 April 2014

One of the problems with improving Legacy systems is that they continue to operate in closed standalone loops. Optimising such systems in isolation may deliver short term efficiencies but a building equipped only with such standalone legacy systems will inevitably over time squander the capital investment in such energy efficiency. The issue is often described by Energy managers as “stopping the drift”. Energy drift inhibits future investment by organisations who (when faced with this issue) begin to doubt the wisdom of throwing more money at the problem. The best approach to improving Legacy BMS systems for efficiency is to introduce an over view enterprise management information system with open protocols which can talk to the various legacy control systems, combine this data with external driving factors and with the use of sophisticated deep analysis techniques highlight energy opportunities and validate the outcomes of energy reduction initiatives as well as derive “smart performance targets”. These targets can then be used to highlight energy drift after optimisation .This type of approach allows for “continuous commissioning” of older legacy BMS systems and combined with proper maintenance delivers big savings in Energy. This paper will describe a number of case studies illustrating real life examples of how this was achieved with older legacy systems in office buildings.