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Energy Audit Success Stories VI

energy audit success stories
By John A. Herbert, REA

Twin Peaks

We audited a building with a central chilled water air conditioning system, serving air handling units, providing cool air to the building occupants.

The main air handling unit controlled the space temperature using a remote air temperature sensor located in the common return air stream, and it controlled the AHU chilled water valve. Its a simple control system, if the room temperature is too hot and the chilled water valve opens, if too cold and the valve closes, it is a typical control arrangement.

However, to save energy a company retrofitted a variable speed drive (VSD) to control the fan speed, and without an easy interface to the existing temp. sensor opted to fit a new return air temperature sensor, next to the existing temp. sensor.

We downloaded and analysed the data from the VSD, unsurprizely we reported the facts, the very expensive VSD never delivered any energy savings.

The VSD could not operate as planned because it used a different temp. sensor. More surprisingly perhaps, the retrofit installation was carried out by an international controls supplier.

This energy brief was one part of a larger energy audit report.


Thats just one of hundreds of energy efficiency improvements we discovered during our energy auditing. Call Kelcroft to order your energy audit today!

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tags: Energy Audit Case Study, Success Stories