An article by Stephen Kinsella
Written: 14 September 98
After 14 years' experience in providing advice on energy saving,
Kinsella Consulting Engineers reviewed their surveying approach
and reporting method.
For many years Kinsella Consulting Engineers had used the energy
audit model of the CIBSE application manual AM5. Although
excellent in principal, this was perhaps biased towards building
services, and was over-complicated as a means of presenting
information.
So how was the energy report to be planned?
Stephen Kinsella decided on an approach based upon computer
modelling of annual energy use. Combining the surveyor's
observations with user questionnaires, records of installations,
building management systems and invoice records, a set of data is
assembled which creates a model of consumption. This may be
broken down into its elements, and compared with metered
records.
The computer model is based on Microsoft Excel and is readily
customised for each project, large or small, and output is
available in the common formats.
The model allows the consultant to carry out 'what if' analysis
to determine the optimum sequence of action. A report is then
produced which schedules "before and after" energy usage and
lists the actions and their capital costs (if any) and the annual
saving. The report takes into account of the maximum payback
period appropriate to the organisation.
One advantage of this method is that it does not have a bias
towards any particular type of solution. Every building or
facility is different and there are very many ways in which
energy may be wasted, from incorrect time switch settings to
errors in the utilities' bills.
Once actions have been taken to reduce costs, managers should
continue to monitor utilities bills to see that the savings are
being made. An energy report should set targets for each bill so
managers can readily see whether the targets are being met.
An operational energy model can be is used for
interactively for assessment of new buildings and facilities in
the early design stage. Working in the design team, alongside the
architect and other professionals, an energy consultant will
create a model of predicted carbon dioxide emission and running
costs and compare this with benchmarks for similar
facilities.
The illustrations show examples from an analytical energy
savings report:
Fig1: Targets
Fig2: Savings
Fig3: Recommendations
This is based on a real case, a facility within a large public
organisation. In fact, in a few items the wastage was so high
that some figures have been reduced for the sake of this article
as they swamped the other savings! The principal of this case
remains -several items made the major parts of the saving, but
there were a larger number of smaller items. The management has
now started to make savings at zero cost by simple maintenance,
and by resetting of controls, and is considering the capital cost
items.
Every facility is different, and there is no "typical" example of energy savings at this level of detail. The report can include some surprises, and may change pre-conceived opinion on the relative benefits of possible actions.
Stephen Kinsella, CEng MIEE FCIBSE is principal of Kinsella
Consulting Engineers, a consultancy specialising in energy
efficient operation and design of buildings.
Figure 1: Example of Energy Cost Targets return to text
Figure 2: Example of energy &
water savings return to text
Figure 3: Example of
recommendations (a screen shot - another project)
return to text
KCE Energy & Environment
The Old Forge Kingston Bridge Clevedon Somerset BS21 6TX
Tel 01934 838624