28/04/2009 – Efficient energy management in commercial buildings. Pat Shiels and Daragh Scaife – Verteco

This was the second the series of GREENprint colloquia, and dealt with energy usage and wastage in commercial buildings. Forty percent of our energy usage can be attributed to usage in buildings, 5% of this coming from commercial buildings. Our energy usage in buildings has increased 120% in the last decade. Fifty of the energy used in buildings is avoidable waste; energy that we would not use if we knew that it was being consumed. Reducing avoidable energy consumption does not alter the environmental conditions in the building, or reduce comfort levels. The big challenge is how to identify where this avoidable waste is occurring, and then empowering building occupiers to be able to prevent it.

At present we have energy ratings for commercial buildings such as SBEM, however this measures the asset rating of the building rather than operational usage. Measurements such as this give an inaccurate picture of the actual energy used by a building as frequently buildings are used for purposes other than that for which they were designed. Dublin City Council has made a big leap forward by insisting that buildings over 1000sqm must have an energy rating of A3 or above. However, if the occupier does not use the building in an efficient manner then this rating is meaningless. It is essential that building occupiers understand how to use their building in an energy efficient manner in order to reduce avoidable waste. Discussions at the end of this session suggested that a soft landing hand-over between designer and occupier is needed for this to occur in all new buildings.

Energy usage in buildings needs to be monitored on a continual basis in order to identify areas where waste could be reduce, one method of doing this is CLEAN, Closed Loop Energy Analysis. However, even when monitoring does occur it frequently isn’t acted upon as the building management system controls are not user friendly. It is important that more accessible and user friendly controls of energy usage are put in place to allow building occupiers to understand where their avoidable energy waste occurs, and how best to reduce this waste. In order to encourage designers and occupiers to spend money on monitoring and control it is important to provide a cost/benefit analysis of the process.

Daragh gave several examples of successful monitoring projects that had lead to significant savings for the client. These included a large shopping centre in the South Dublin area who saw a 45% reduction on usage and a payback on their project in five months, as well as the UK court service buildings and Harrah’s hotel and casino. All these examples highlighted that monitoring using a system such as CLEAN helps the client to identify areas of energy and resource wastage, by also assisting the client in altering their building management system this wastage can be eliminated creating significant savings.