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

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.