Steve Avery, Carrier UK national customer services manager, believes successful commissioning depends on training and experience and awareness of the changing regulatory environment
COMMISSIONING is an engineering activity that is too frequently taken for granted. Rather than the standardised following of procedures, equipment commissioning is often about coping.
Coping with obstacles that can so easily get in the way of the successful handover of a completed installation. It takes an experienced commissioning team to overcome some of these.
Training is also essential to both coping and to keeping up to date.
Equipment is changing more frequently than ever and is becoming more complex, especially on the controls side. Therefore training has to be current.
In general, engineers are the sort of people who are very good at keeping up with changes in their regulatory environment. But sweeping industry reforms, such as the new Part L, mean support from employers is also essential and without it any commissioning team is virtually worthless.
Carrier provides its engineers with weekly, sometimes daily, technical bulletins. Too often the commissioning team becomes the poor relation to the sales business or to the maintenance teams.
Fortunately, this year Carrier has recognised that constant review and renewal is key to consistently high customer service and has restructured its commissioning department with a clear customer service focus, nationwide.
Many of the situations which commissioning engineers additionally have to cope with feature the unpredictable. Too often waterside services have not been commissioned before arrival on site or electrics haven't yet been run to the chiller. Even if connected, these services are double-checked and sometimes faults are found.
Risk management planning is therefore part of the commissioning engineer's toolbox. Carrier tries to make risk management plans that even take rare occurrences into account.
The sheer quality of commissioning is crucial to the functioning of any installation. Good commissioning, as now stressed by CIBSE, requires involvement 'early in the life of a project' and requires 'specialist skills and knowledge'. It also envisages 'good maintenance practice and periodic re-commissioning'.
Unfortunately, too often in the UK, the need for maintenance and the opportunities for re-commissioning are ignored. Hopefully the new regulatory regime will have some impact on this. Of course, most warranties are invalid if maintenance is not in place but huge efficiency benefits can be ensured if the subsequent service engineers understand the commissioning regime.
Standard features on air conditioning systems are improving all the time. Their full use may not have been specified but the alert commissioning engineer will see if any of the features can be employed to enhance the service that the system will give the end-user. In refurbished installations the opportunity will also be taken, where possible, to improve the quality of service that a system is giving.
Energy efficiency improvements are a popular area for the service-oriented commissioning engineer, as it is often possible to give clients more than has been specified. By focusing on the comfort system of a building as a whole, instead of just commissioning the chiller, it is possible to provide 'added value' and go a long way towards integrating the HVAC system into a single optimised whole.
Carrier's Chillervisor proprietary control system, for example, has extensive control capabilities when it comes to system integration on large systems. Carrier's latest open protocol* based Aquasmart Plus system can now also provide system integration on smaller systems.
Data centres provide a good example of energy-sensitive commissioning and re-commissioning procedures, of the type that seems to be envisaged under Part L. Typically, data centres are designed for full load and 100% back up. But they usually take a number of years before they are operating at full capacity. Rather than allow such systems to operate at very low part loads all of the time, with inordinate amounts of switching on and off and the concomitant starter motor problems, reduced life expectancy, and environmental impact, it is possible to re-commission an existing data centre system to use the machines' sophisticated controls to schedule equipment use to run the chillers at their optimised load conditions, while sharing the loads more appropriately over time.
Another example of proactive commissioning occurs when an area in any building is not using all the cooling being supplied. Set point controls can be changed to allow more dynamic adjustment, so that load is more accurately matched to building need. And if there is still cooling available in the return water, for example, this can be monitored and the cooling capacity available can be used before calling for additional cooling.
Under Part L it should become part of the new type of commissioning regime envisaged to ensure that appropriate maintenance protocols are put in place. When it comes to refrigerant containment, for example, a vital part of the new rules, prevention is better than cure and that means regular maintenance and leak testing. Refrigerant logs will soon need to be provided, by law. This has always been best practice but will be new to many.
Service is required even during a warranty period or the warranty is invalidated. The need to prove leak testing will show up the all too frequent situations in the UK where this is not being adhered to. Such provision is often in the original specification but sometimes isn't asked for in the final agreement, often because the spec of the system is altered along the way.
Manufacturers will soon be offering ongoing data management for their equipment. At commissioning the appropriate controls systems can now be set up to analyse and report on equipment performance. It is a skill to interpret the data provided by systems that operate using fuzzy logic but it is a skill that the best commissioning engineers have at their disposal as a result of their relationship with the equipment. It makes a great deal of sense for the commissioning team and the ongoing maintenance team to be very closely aligned.
*Open protocol is a common digital language platform allowing different manufacturers' controls to interface easily without custom-written interfaces.