Predictable benefits

Dan Mizesko, managing partner of US Chillers, discusses the virtues of predictive maintenance.

fmME: How advanced is the maintenance industry in the UAE and around the Gulf?
I feel the liquid chiller service industry is far behind in this region, the reason being that, before 2001, everyone had to rely on the OEM or its agents for chiller services, and had to pay whatever the cost, and wait however long for service, as this was a monopoly market. This is no longer the prevailing situation.

fmME: Are customers paying more attention to maintenance in an effort to cut overall costs?
I have found that customers always value maintenance. However, their expectations were always very low. US Chillers brings you the most advanced technology available in the industry.

If your equipment fails unexpectedly, you face downtime and potentially inconvenienced occupants. With predictive maintenance, you will know about potential problems before breakdowns occur.

This will bring you the ability to schedule repairs before they become more costly – and at times when they will not inconvenience you or your building occupants.

Using today’s best testing tools and technologies, we can discover, or rule out, virtually any kind of hidden system problem. As a result, we can offer tangible assistance:

• Find, identify and correct minor problems inexpensively before they lead to more complex and expensive repairs;
• Avoid needless downtime and inconvenience or discomfort to occupants;
• Ensure continued production when equipment is used in process applications;
• Control energy cost;
• Prolong equipment life, thereby deferring replacement cost, and
• Prevent overtime cost for unscheduled repairs.

Predictive maintenance is key to optimal building systems management. With this you can make the most informed decisions and achieve the lowest overall operating cost.

Some of the predictive services we offer are vibration analysis, thermographic testing, eddy current testing, water/oil/refrigerant analysis performed by an independent US laboratory, motor insulation testing, ultrasonic flow analysis, chiller performance and energy analysis.

fmME: What are some of the main maintenance or service-related issues you come across regularly?
To be quite honest, the most common things we find are that chillers have not been correctly commissioned and started to factory specifications, and are maintained at these same poor standards.

This puts the end user – whether it be a district cooling utility or a building owner – behind the eight ball, so to speak, from day one, and it is downhill from there in terms of energy and reliability.

Our commissioning, decommissioning, continuous commissioning and retro-commissioning are premised on the core philosophy that we can assure the end user and owners of the facility that the chillers are operating as per design from the moment we perform our services.

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.

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.