Prepared by Ken Sinclair, Sinclair Energy Services Ltd
KEY TO BUILDING PERFORMANCE
Using DDC Systems Effectively
to Improve Building Performance
Sinclair Energy Services Ltd
The main function of the company has been one
of providing energy conservation expertise to all levels of government, universities and
AEE Seminar - Using DDC Systems Effectively
to Improve Building Performance
(30 minute presentation with questions)
1. For the DDC tool to be effective it must be simple to use
and self teaching, and lead operators to improved building performance.
- People are not willing to tolerate anything more complicated
than point and click.
- The Internet has greatly increased everyones
expectations as to what is user friendly interface is. Our clients and managers are no
longer willing to accept DOS like interfaces. Windows like platforms have become the
accepted entry level. Freedom of manipulatible information is expected at all levels of
integration with our building performance control systems.
2. Achieving and maintaining implied simplicity through good
- A good graphic interface in todays DDC systems is
mandatory. Good graphics allow management to focus on the real problems. Good graphics
allow clients and all other resource providing non-code junkies to participate in
improving building performance.
- Again the Internet has reconfirmed that the power of dynamic
linking, when combined with powerful graphics can simplify complex subject matter. Our job
now is to present our complex building relationship in an easy to understand interlinked
graphic pages that can be reviewed easily by anyone while gaining valuable information as
to the intent of the system teaching all who use the system building system configuration
and relationships. A primer for basic building performance graphic interface exists on the
net as part of the BC Buildings Corporations Client Comfort Design Manual.
- The Graphic Guidelines Section 7
provides guidelines to effective graphic generation.
3. Using trend graphs effectively to identify successes and
- Trend graphs are powerful indictors of building performance.
Trending the same points with different time bases provides new information. Zoom and
scroll can allow interactive interface with powerful trend graphics.
- Trend graphs are a powerful graphic representation of dynamic
building performance indicators. Almost all of our DDC systems available today are able to
generate excellent trend graphs. The problem with most systems is that obscure coding and
or menu manipulation, plus knowledge of where information is stored, is necessary to
unleash these powerful trend graphs. The navigation graphic set trend icon provides a
simple method of linking and organizing trend graphs so that they can be easily used with
one point and click. Setting up the same trend data with a different time base provides a
new view of building performance. An example is building energy used on a 24 hour basis
provides different information than a weekly time base. A monthly trend of daily energy
usage provides yet another view. All trends can be generated from the same point.
4. Using a trend of the energy bell curve as an optimization
- Daily, weekly and monthly bell curves provide the building
- The above building energy performance curve provides an energy
fingerprint of building performance. The DDC system Operator Control Language (OCL) can be
used to generate the highest and the lowest level achieved since reset. This graphic
information reduces the operator task to try to match todays consumption to the
lowest level of energy usage achieved. In some projects the lowest level is the
demonstrated lowest level and is not reset but left as a goal to be achieved by operation.
The highest level shows the mistakes that have been made which can provide a valuable
lesson as we understand what combination of building operation caused the problem.
5. Wringing savings out of the bell curve.
- Analyze bell curves. Share bell curves with others who care
about improved building performance.
- If we analyze the energy bell curve our objective is to reduce
the area under the curve (the energy consumption) by lowering the hourly peaks (the
building power usage). By using curve fitting we can analyze other curves generated by the
system such as major ASD loads, sub-metering, etc. On off schedule, chiller operation,
other major load operation can be visually observed. The relative impact of every
interaction is depicted on the energy bell curve.
- The effect of lights off sweeps and cleaner interaction can be
analyzed. I recommend sharing this information with the cleaners. When they see
graphically the effect they have on total building energy usage even the traditional are
receptive to change. Constant sharing of information from our powerful DDC tool will lead
to improved overall building performance.
6. Output oriented
- Use runtime totalizers: - The sum of all the parts should
equal the whole. Use analog trends on outputs with bell curve analysis:- If all outputs
are scaled for 0 to 100% energy use, the trend output will present a graphical picture
under the curve of the energy usage.
- Runtime totalizers are extremely useful in diagnosing building
performance problems. Using OCL to generate a kW estimation of each fan and pump allows
the relative importance of each device to be demonstrated. This same estimated kW total
can be continuously added to determine motor portion of total building kW load and plotted
on the energy bell curve. Some runtime totalizers when given an analog value will totalize
it. The rolled up estimated number can be extremely useful in estimating the portion of
energy used daily, weekly and monthly by each component.
- Proper setup of all analog values allows all trends to present
a bell curve of each analog output. The area under the curve provides a graphical
representation of energy usage.
- The brief presentation time limits the detail in which this
subject matter can be covered. The subject is likely the basis for a day seminar which
would include lots of feedback from DDC users sharing their successful concepts. I did not
spend much time talking about the value that good navigation graphics and trend graphics
have for maintenance. Malfunctioning equipment is quickly uncovered with powerful trend
logs. The navigation graphics allow quick identification of what devices are not operating
correctly and allows manual intervention to solve problems until devices can be repaired.
- I feel that everyone including myself, can greatly improve on
how our powerful DDC systems' navigational graphics can simplify and optimize building
Ken Sinclair, ESI Enviromation Services Inc/Sinclair Energy
Services Ltd Tel: (250) 656-5378 Fax: 656-2394 E-Mail: email@example.com
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