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

Condition Survey, Air conditioning Issues…

by John A. Herbert

chiller motor oil leak Hong Kong

There is a saying “An ounce of prevention is worth a pound of cure”, the photo illustrates how to ignore that, we have a 900 Kw 3 phase electric motor, an oil leak, and newspaper stuffed underneath catching dripping oil, that should send alarm bells ringing in every office across the land. Perhaps we need a fire triangle refresher course?

On the topic of condition surveys, I am often asked does the Kelcroft energy audit include condition survey? Yes, is always the answer, it is not an optional extra ASHRAE and other energy auditing standards call for it, an energy audit requires examination of the condition of the plant and equipment as part of the energy assessment to understand its efficiency, in tropical Hong Kong, that will include the central air conditioning plant, including the chillers, the automatic controls, differential bypass valves, variable speed drives, chilled water and condenser water pumps, cooling towers and the like.

In the energy audit report, it will identify any defects, or deferred maintenance issues discovered.

So back the high risk oil leak, literally one stray spark from disaster, the building owner does not know, the building management seem equally oblivious and never reported it, yet we know an ounce of prevention is far far cheaper than the cure.

About the Author

John A. Herbert is a veteran professional with more than 30 years solid construction experience, educated in the United Kingdom he has been working across Asia for the last two decades, serving international, and local companies. And involved with the development of Hong Kong Green Building for more than a decade. He is a Hong Kong Registered Energy Assessor (REA), and a BEAM Professional.