Chiller Optimisation Showing where to Save

The brand of Vitasoy is not only a household name of beverages in Hong Kong, but equally well known worldwide. The existing plant has been in operation since 1980’s and its operation requires chiller units which cool mainly office space as well as some manufacturing and storage areas. The cost of operating the chillers contributes significantly to Vitasoy’s overheads.

To further enhance the energy efficiency, CLP conducted Chiller Optimisation Services on all four chiller units by using comprehensive and non-invasive measurement techniques to determine the actual performance of each unit over time. From site measurement, CLP discovered that the coefficient of performance (COP) for one of Vitasoy’s air-cooled chillers had deteriorated significantly, from the manufacturer’s specified level of 2.32 to 0.68. This chiller could not help the other 3 chillers sharing the heat load as it was only running at around 10 to 20% efficiency most of the time and also worsen to direct the flow of chilled water into this insufficient cooling plant.

Replacing an Inefficient Chiller Unit Increases the COP Significantly

With site verification and recommendation from CLP, Vitasoy decided to replace the inefficient chiller unit and was completed in January 2015. Since the COP for the new unit is 3.2, Vitasoy can save roughly 80% energy cost through this chiller replacement alone. The company expects the payback period within a year and a half.

Manually Sequence for Optimum Efficiency for Added Savings

Through measurements taken from different chiller units during various part load conditions, CLP further recommended that Vitasoy manually sequence the operation of the four chiller units to attain even better energy efficiency without adding any investment cost.

If some chillers would give superior performance than others in full load or part load conditions, it should be switched on first and for most of the time. The operator is also reminded to keep existing chiller units full load as far as practicable before switching on additional units in part load conditions. Therefore, another 5% in energy savings are expected to achieve.

"Improving efficiency levels is critical to our bottom line and an essential part of our drive to protect the environment. CLP’s Chiller Optimisation Services was extremely effective in addressing the area to enhance efficiency,” said Mr. Herbert Lee, Senior Manufacturing Manager, Vitasoy.  


Centralised Dishwashing with Energy Efficiency and Quality

Experiencing the shortage of dish wash manpower especially during festive seasons, two owners of restaurants decided to set up Diwash in year 2011. It is a centralised dish washing system and the first-ever service to relieve the pressure of manpower shortage. The service not only enhances the dishware cleaning quality and working environment, but also creates the positive chain effect of green initiatives to the restaurants.

Diwash is equipped with fully automated facilities. With CLP's assistance in last year, the company adopted full electric operation for three process lines in Kwai Chung workshop in order to reinforce their energy saving practices. Having conducted the Energy Audit service from CLP, the energy efficiency of system was further enhanced.

As Diwash requires significant supplies of hot water, CLP recommended the use of energy-efficient heat pumps which are able to provide stable supplies and constant temperature of hot water in 24-hours. This solution can cater long operation of air conditioning and hot water supplies while supporting the pre-wash operation. The heat pump can simultaneously generate hot water and cool air with significant saving in energy cost of 66% for washing operation and corresponding start-up time was shortened from 30 to 10 minutes.

To enhance the working environment and energy efficiency, Ricky Au and Alex Liu, managing directors of Diwash, are adopting the LED, compact fluorescent lamps and planning to install heat pumps in other workshops.


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