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Continuous Commissioning (CCx)
by John A Herbert
Building Services commissioning (Cx) is a vital but often overlooked part of the project development contract. Viewed by many as a last minute chore, it is rushed, a final activity block before handover, practical completion and hopefully payment.
Yet
surveys indicate that too many of our buildings are not correctly
commissioned, and this leads to GWH of wasted energy every year. The
reasons for poor and inadequate commissioning are
numerous, programme
constraints being very common excuse.
During the project, with a fixed completion date, some construction activities are inevitability delayed. To avoid the often crushing damages the time initially set aside for commissioning is absorbed to complete the project work. Since commissioning is seen as merely a sub-contract issue, the main contractor wouldn't normally think to apply for an extension of time.
The original programme might include a reasonable period perhaps eight to ten weeks alloted solely for commissioning. However, years after the programme was conceived, the last minute scrambling to finish the project often means only a few days are provided for commissioning.
If commission occurs during the summer month when the air conditioning systems and chillers are operating at full load there sis little time and effort spent to consider part load conditions.
Four Seasons
Another complexity of commissioning is the weather. Some Building Services installations are designed to operate during certain periods of the year.
For example trying to fully commission a heating system designed for winter operation during July and August would be futile. Some contacts recognize the difficulties and specify further commissioning and system tuning to be made during the appropriate season.
Re-Commissioning (Rx)
From the external appearance a building appears static, it doesn't move or change its outlook very much during its lifespan. Internally it is a different matter, renovations, the demands of day-to-day operation, and the continuous wear of mechanical parts means constant change.
A new tenant could demand a new generator set or additional cooling, requiring new wiring, piping circuits and equipment to be installed. Add to that, our existing pumping systems need regular maintenance, and as parts fail, the pump casing, motors, pulleys, and drives would be replaced.
Experience indicates that most buildings have a limited Planned Preventative Maintenance System (PPMS) in place. Without the demand for in-house resources, the work is farmed out in discreet and totally independent sub-contract packages (For example, the air-conditioning work is sub-contracted to an air conditioning contractor) with little co-ordination to the other trades.
Additionally historically maintenance activities are not well documented. When the inevitable failure does occur, emergency repairs often demand the quickest fix possible, a failed motor is replaced with any serviceable unit in stock, irrespective of its energy efficiency for that application.
The result, many older buildings have poorly operating Building Services systems, therefore the concept called Re-Commissioning (Rx) was introduced. As the name itself suggests, each of the engineering systems are methodically "commissioned".
Amongst the many findings, chilled water systems with isolating valves fifty percent (50%) closed, and commissioning valves hundred percent (100%) open gives clues to past problems and the quick fix.
One common factor is the necessary advance remedial work, perhaps this would include updating the automatic control settings, fixing disconnected actuators, etc. before the actual commissioning work can be undertaken.
However, it is important to do some detective work first, finding the root cause to explain why the actuator linkages were disconnected in the first place. These answers point to existing operating problems that Re-commissioning need to remedy.
Kelcroft
conducts energy audits to lower your building
operating cost, without sacrificing occupational comfort. Commissions
are undertaken range from the small energy assessments to major
projects. Surveys indicate that more than
seventy five
percent (75%) of buildings
are operating incorrectly, have inappropriate operating and maintenance
contracts or are waste money through inefficient energy usage. And all
too often the energy management systems installed to reduce operating
costs, don't function as intended adding to further wasted energy.
You wouldn't operate your business without an accountant to oversee your finances would you? Likewise an annual energy audit ensures that your energy cheque book is balanced too.
Energy costs rise every year, tariffs increases are
threatened, and oil
prices are soaring, these effect your bottom line - Kelcroft energy
audit helps identify waste and reduce your energy bills.
Approach
Kelcroft's approach takes a holistic view, a total energy
approach. Our
energy audit considers the total picture, not just the low hanging
fruit - an overall energy cost in use perspective.
The goal is management of resources without
sacrificing end-user
comfort. Our energy audits are conducted in accordance with
international standards, and local EMSD guidelines as required. Energy
auditing needs to be conducted on the ground, energy can't be saved
without inspecting the nuts and bolts on site.
Energy Losses
Finding and identifying energy waste, energy auditing reveals
the
underlying losses, don't be left in the dark.
A building owner in Hong Kong was shocked to discover the cold hard facts, his maintenance operations had obviously let him down...read more
Another example of High rise waste, a commercial building in Hong Kong operates six days a week doesn't it? unfortunately the truth is stranger than fiction...[read more]
Energy Auditing
An energy audit is the systematic review of each fuel, and
energy
consuming system in your building.
It commences with the collection, and analysis
of all information
that may effect your buildings energy consumption. Reviewing, and
analyzing the condition and performance of existing systems,
installations, existing management techniques, and utility bills.
We compare your facilities energy performance
with published standards
(benchmarks) for your premises and activities of a similar nature and
provide proposals. An energy audit is not an excuse for cutting energy
consumption, rather managing the usage to maintain and or improve
occupant comfort.
An annual energy audit is
much like your annual accountant review,
stating the past and current energy balance.
Energy Report
The Kelcroft energy audit report summarises our findings, and is sub-divided into three energy management sections, namely:
Within these three
sectors, we explain energy
saving options and
opportunities for your review and implementation.
Housekeeping
Housekeeping measures are improvements involving virtually no
cost, and
involve relatively simple steps to start achieving energy savings. For
example training courses to increase energy consumption awareness
amongst your staff.
Operation measures
These improvements necessitate some change within your
existing regime
or maintenance strategy.
For example lighting modifications, improved
the switching arrangement
or implementing a new lamp replacement strategy benefiting from the
efficacy of the latest technology.
In the majority of cases, the working environment for your
customers is
improved.
Capital works
Capital works would be major improvements to your premises or
systems
that will require significant expenditure.
Examining your installation, analyzing your
operating and maintenance
costs, and evaluating possible options for energy conservation. Viable
proposals that will benefit you financially are offered for appraisal.
For example
switching to water
cooled air conditioning (cooling towers) under the Hong Kong pilot
programme or
consideration of cost effective cogeneration solutions.
Energy Audit Financial Analysis
The energy analysis would comprise a practical and economic
evaluation
of viable energy saving options. This evaluation would include an
investigation of all the various elements that contribute to your
owning and operating costs.
Typically these would comprise:
Each of the elements
would be analyzed to gauge the
overall economic
viability of a particular energy-saving strategy or programme.
Initial expenditure
Defines the money required to purchase the plant or equipment
(CAPex).
Cost in use
Cost in use is the operating and running costs for the
installation
based on the data retrieved during the energy audit (OPex.)
Investment analysis
Investment analysis comprising fiscal, payback and net present
value
calculations, these tools are primarily used to establish if a proposal
would recoup your investment during a specific period.
Payback hurdles would be established to meet
the needs of the
organisation.
What's Next?
Kelcroft's long standing expertise helps building owners and managers enjoy the benifits of lower energy costs, particularly our experience providing E&M capital works projects.
We have unique knowledge, gained across three continents, backed up with our experience from many years of building services design and operation. We help organisations lower operating cost to leverage a competitive advantage.
Call Kelcroft today, our Hong Kong office telephone: +(852) 2335 9830, send us a fax +(852) 2335 9862, or send us an email message
About the Author
Mr
John
Herbert is founder and director of Kelcroft E&M Limited. He is
a sustainability authority with nearly thirty years experience gained
over three continents, and is often invited to speak on engineering
topics. He is a member of various industry committees
working to create a better living environment in Hong Kong and
Asia. Click
here to learn more.........
Keywords: Continuous commissioning CCX
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