retro commissioning by John A. Herbert

The principal is sound, if not the name. If you are old enough to remember the adverts for a crypton tune-up, you’ll understand the gist.

Due to mechanical wear and tear the engineering systems in our buildings inevitably need attention, and some twenty years ago, the phrase re-commissioning entered our vocabulary to brand the process of tuning the often forgotten ACMV systems.

But it is not really commissioning, not even close. Commissioning occurs after a new system is installed and those static systems are set into operation for the first time, complete with the countless startup and shutdown checklists.

Here in Hong Kong, T&C (Testing and Commissioning) is commonly used for starting new systems. To fix old buildings, the term “commissioning” is a misnomer in my view, it simply doesn’t apply to an existing system already operating.  Building tuning, my preferred term, is apter. We want to check and adjust, not start from scratch. For example, for the chilled water circuit, the point of re-commisisoning, as it is called, would be to check the flow rates and pressures satisfy the design intent, Because pumps and motors may have changed, the control valves need checking, what’s the value authority, etc. From experience, flow direction labels installed backward are confusing.

John A. Herbert energy expert

Indeed, a key target for undertaking re-commissioning is the same as an energy audit, to find cost saving opportunities and lower operating costs. Particularly for air conditioning systems, warmer weather over the last three years has caused increased energy costs, and the Observatory is predicting that this season will be another record.  Yet, some buildings are still operating today where the set points were checked at Practical Completion.

Yet, some buildings operating today have set points last checked at Practical Completion. Although buildings appear to be static, internally the mechanical and electricity systems need attention.

For advice regarding re-commissioning contact the experts today!

secret life of Variable Speed Drives by John A. Herbert

Following the success of the secret life of chillers, the secret life of Variable Speed Drives (VSD) might be equally important.
John Herbert hong kong energy efficiency expert

Variable Speed Drives (VSD), also known as Variable Frequency Drives (VFD) can replace motor starters and lower energy costs, but this graph above (real data) shows the motor speed remains pretty constant all day long.  Continue reading

Green Building defined by John A. Herbert

green building, john herbert is green building expert

by John A. Herbert

What is the definition of green building? First, some definitions [1] from around the world. Continue reading

Secret Life of Chillers by John A. Herbert

energy audit expert

Every energy audit is the same but different, the goal, searching for cost and energy savings is the same. whether its factory or office. And we follow the same published process, yet every energy audit guide attempts to detail how to identify those cost savings, and that is where the document evolves from its clinical, prescriptive list of requirements into vague generalizations because examining data, sometimes imperfect data, to find cost savings is more art than science. Continue reading

your life in the hands of the building owner by John A. Herbert

fire safety, fire survey, Hong Kong buildings

Considering Hong Kong’s maze of skyscrapers you might be surprised to learn that the Hong Kong fire department does not routinely check your building. After opening building fire safety, and your life, rests with the building owner. Once a year the building owner must engage a Registered Fire Services Contractor to check the fire fighting equipment, that is the theory.

Continue reading

No excuse to delay energy upgrades on HK Island by John A. Herbert

Funding Energy Upgrades

John Herbert - Green Building Seminar 2011
Cost is always the key issue for energy upgrading projects right? Yet dollar matched funding, upto HKD 200,000 is available for residential projects on Hong Kong Island. For example, for Incorporated Owners (IO) where the total cost of your energy saving project is for example HKD150,000, HKD 75,000 is refunded!

Kelcroft is a Qualified Service Provider (QSP) with practical expert advice to lower your costs, and energy consumption, call the experts today!

For commerical buildings you might be interested to view our Hong Kong Building Energy Consumption Mapping Project (beta) web page.

About the Author

John A. Herbert is a veteran energy expert with more than 30 years construction experience, educated in the United Kingdom he has been working across Asia for two decades for international and local companies. He is a Hong Kong Registered Energy Assessor (REA), and BEAM Professional.

Improving Hong Kong’s Green Buildings looking forward by John A. Herbert

by John A. Herbert
green building, john herbert is green building expert

In the 2017 Policy Address by CE C.Y. Leung there is just hint that the present loophole that allows non-green buildings to obtain GFA concessions will be tightened. Continue reading

Smart Building Label

What is a smart building label? It is an independent certificate to demonstrate your building is a really smart building. The public is tired of self declarations, particularly in the green space, there is even a term for it “greenwashing”, it is too easy for a building owner to simply declare my building is “green” or my building is smart building, without it undergoing any independent assessment.


Leaking Ducts by John A. Herbert

leaking air ducts, air conditioning, waste energy

Air Conditioning is expensive and it is the highest portion of your energy, so after buying the central chiller plant, and the cost of energy to provide chilled water to air conditioning units, your precious and expensive conditioned air leaks out, through poor maintenance, wasting energy, and also causing condensation. It is the same as throwing the hundred dollar bills of the roof every day. In energy auditing, as in life, details matter.

Every fire damper in Hong Kong must be inspected annually, in air conditioned ductwork after a few years the access panel (shown in the photo above) is no longer air tight, allowing leakage of expensive cold air, and energy losses. Alone, each energy loss is not significant, across the Hong Kong millions are lost every year.

About the Author

John A. Herbert is a veteran engineer with more than 30 years construction experience, educated in the United Kingdom he has been working across Asia for the last two decades engaged by international and local companies. He is a Hong Kong Registered Energy Assessor (REA), and BEAM Professional.