Predictable benefits

A typical York chiller.

I can assure you this is not the case on almost 100% of the chillers we have come across in the region; but this holds true as well in the US, South America and worldwide.

A survey report by the San Diego State University Energy Engineering Institute on 31 chiller plant sites across the US found that chillers which should have been operating in a range of from 0.65 to 1.00 kW/ton, according to the OEM specifications, were often actually operating at 1.5 to 3.0 kW/ton, and that most chiller plant operators had no idea how well their chiller plants were performing.

A survey report on 14 plants by the Northwest Energy Efficiency Alliance found a substantial variation in chiller energy efficiency, ranging from 0.55 to 1.80 kW/ton.

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A report by the California Energy Commission stated that buildings and chilled water central plants invariably do not perform as well in practice as anticipated during design.

The main reasons for this are improper equipment selection and installation, poor feedback on operational performance and energy performance and lack of rigorous commissioning and proper maintenance.

What we have found in this region is that water-cooled electric centrifugal chillers are generally selected and designed to operate in the range of 0.687 to 0.760 kW/per ton. We looked at 2003 to 2009 operational data, ranging from newly-constructed and commissioned plants to five-year-old plants, as well as chillers up to five years old.

All were electric-driven centrifugal plants. We determined that the operating range of these chillers, before chiller diagnostics, corrective service procedures and chiller optimisation strategies were applied, was between 0.98 to 1.8 kW/per ton. Of the chillers that these services and strategies were applied to by US Chiller Services, the kW/per ton now ranges between 0.513 ~ 0.759.

fmME: Maintenance is a critical part of energy efficiency. Are you finding a growing awareness of maintenance strategies?
Unfortunately, I am not finding the awareness of maintenance or operational strategies for ‘green’ issues being addressed with the urgency and importance due them.

It is unfortunate that the majority of the end users feel that if they have a BMS, energy management or facility control system installed, they have achieved a ‘green’ solution.

The fact of the matter is that a proactive recommissioning, predictive and preventative maintenance program on the chillers will save more money than almost any other ‘green’ solution available.

The chillers account for the bulk of the energy consumption. Unless the chillers are, first and foremost, operating in peak condition, huge amounts of kWh and associated money is being wasted, which no control system can correct.

The priority for district cooling, building owners, shopping malls or any industry or facility that has liquid chillers has to be proactive professional chiller services and maintenance being applied, so the kWh achieved and attendant money savings become the biggest contributor to the region’s sustainability goals.