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Continuous Commissioning

John A. Herbert
John A. Herbert

Commissioning (Cx) is a vital but often overlooked part of the project development contract. Viewed by many as a last minute chore, the final block before handover, practical completion.

continuous commissioning building tuning

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 commissioning occurs during the summer months when the air conditioning systems and chillers are operating at full load there is little time and effort spent to consider part load conditions.

Four Seasons

Another complexity of commissioning is the weather. Some Building Services installations are seasonal.

Try commissioning a heating system, designed for winter operation during July or August, it would be futile. Some contacts recognize the difficulties and specify further commissioning and system tuning to be made during the appropriate season.


Externally buildings appear to be static, it doesn't move or change its outlook change very much during its lifespan. However, inside is a different matter, renovations, the demands of day-to-day operation and the continuous wear of mechanical parts means change is constant.

continious commissioning

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, 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 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 poor 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.

This results in 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. Cooling tower fill saturated with mud, etc.

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.

However, the term Retro or Re-commissioning (Rx) tends to support the notion that Rx this is another once in a life time event, in my view. Building Tuning is a better term, supporting the idea that continuous tuning and improvement yields the best results.

Building tuning is a regular review of the systems where faults can be diagnosed, and repair work carried out.

Another Tool

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. 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]

What's Next? 

Kelcroft's long standing expertise helps building owners and managers enjoy the benefits 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

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 often invited to speak on sustainable 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.........

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