Overview of Building Diagnostics.
Overview of Building Diagnostics.
(827 K)
House, J. M.; Kelly, G. E.
National Conference on Building Commissioning.
Proceedings. May 3-5, 2000, Kansas City, MO, 2000. AND
Diagnostics for Commercial Buildings: Research to
Practive. Proceedings. June 16-17, 1999, San Francisco,
CA, 16-17 pp, 1999, 1-9 pp, 2000.
Keywords:
building design; diagnostics; fault detection;
monitoring
Abstract:
Modern buildings are being designed with increasingly
sophisticated energy management and control systems
(EMCS) that have seemingly limitless capabilities for
monitoring and controlling the conditions in buildings.
Nonetheless, building heating, ventilating and
air-conditioning (HVAC) equipment routinely fails to
satisfy performance expectations envisioned at design.
Furthermore, such failures often go unnoticed for
extended periods of time. How does this happen? There
are a number of explanations. First, HVAC equipment is
typically instrumented with the minimum number of
sensors sufficient to implement basic local-loop and
supervisory control strategies. Lack of sensor
information is a significant barrier to assessing the
operation of the equipment. A second explanation is
that the data that is collected overwhelms building
operators because there is little effort to consolidate
the information into a clear and coherent picture of
equipment status. Trend data from today's EMCS are
useful, but only when analyzed by a human, and this is
not a cost-effective way to continuously monitor system
operation. A third explanation is that building
operators may overlook symptoms of a failure because
they may not fully understand the control strategies
implemented. A related explanation is that lack of
understanding of sophisticated control strategies leads
to manual overrides that may temporarily alleviate a
problem, but may lead to unintended and undetected
operating problems in the future. Undoubtedly other
explanations exist; however, there is little argument
that there is vast room for improvement in the way
buildings are monitored.
