Delivering successful commissioning
It is important that the construction phase allows adequate time properly to commission building-services systems in full accordance with the requirements of Part L and the requirements of the CIBSE Commissioning Code.
Hywel Davies reminds of the importance of commissioning — and where guidance is to be found. Commissioning buildings and their services is vital if they are to operate efficiently and effectively in accordance with the design intent. However, it is often not carried out — or carried out systematically. Since buildings in the UK account for 46% of energy demand, they are a key target for action to improve energy efficiency and reduce carbon emissions. So commissioning is now a statutory requirement for both domestic and non-domestic buildings, under Part L of the Building Regulations. The CIBSE Commissioning Codes* have been developed over a number of years to set out, clearly and systematically, the steps that should be followed to commission building services in a proper and timely manner. They define commissioning as ‘the advancement of an installation from the stage of static completion to full working order to specified requirements’. In other words, it is the process of getting services plant and systems up and running, as they should be found when the first occupiers arrive in the building. Commissioning, especially on larger more complex buildings should be undertaken by a specialist commissioning engineer. This key activity, which by necessity occurs late in the construction of a building, enables the commissioning engineer to ensure that systems operate as they were designed to do. When coupled with good maintenance practice, commissioning and periodic re-commissioning help provide building occupiers with a safe, reliable, good-quality and comfortable internal environment using heat and electrical energy, whether from on site renewables or the grid, efficiently and cost effectively. Compliance with the guidance contained in the CIBSE Commissioning Codes will help to achieve compliance with the current requirement of Part L of the Building Regulations for commissioning of fixed building-services systems. It also provides a clear industry standard for the specification and delivery of the commissioning process. Good commissioning of buildings requires specialist skills and knowledge. Although occurring late in the construction phase, commissioning also requires input early in the life of a project, when key decisions relating to the construction process are taken. The CIBSE Codes therefore give the strongest encouragement to designers and clients to consider commissioning and to seek specialist input at these earliest stages. Approved Document L2 emphasises the need for commissioning to be certified by suitably qualified persons, and building-control bodies have been encouraged to satisfy themselves of the ability of project teams to fully comply with this requirement. Although this has not always been the highest priority for building control, the pressure on delivering real carbon emissions reductions may change that. The CIBSE Codes are organised into a set of system-specific guidance for air systems, boilers, controls, lighting, refrigeration and water systems. Code M provides an overarching guide to the management of the whole process and the integration of the whole commissioning process to deliver working systems in total. Code M presents current standards of good commissioning practice in the form of a series of recommendations and guidance. The ‘Commissioning management code’ may be used in a variety of contractual frameworks, and users need to ensure that its use is considered when contractual arrangements are being made to ensure that its recommendations do not conflict with those of the contract. In particular, it is important that contractual arrangements make due allowance for taking the needs of commissioning engineers into account during design stages and that the construction phase allows adequate time properly to commission building-services systems in full accordance with the requirements of Part L and the code. The ‘Lighting commissioning code, Code L’ is a slightly different document in that lighting systems tend to be stand-alone systems, whereas air, water, controls and refrigeration systems are often combined, as are boilers, water and control systems. By contrast, Code L advises on the commissioning of internal lighting systems and their associated control systems. It describes standards of good practice, presented in the form of recommendations and guidance. Although many of the ideas can be applied for external lighting, Code L does not include specific commissioning checks for road lighting, sports lighting, historic building exteriors and rural areas. Code L is intended to be used as a guide to good practice for the commissioning of lighting and its associated control systems and as a tool to assist the definition of commissioning procedures and preparation of commissioning specifications. Proper commissioning makes a significant contribution to achieving properly commissioned buildings that occupants enjoy occupying. It is time we did more as an industry to ensure that commissioning ceases to be the Cinderella of the construction process and is seen far more as the culmination of that process and the delivery of a working asset to the owner or occupier. Hywel Davis is technical manger with the Chartered Institution of Building Services Engineers.
Related links:
Related articles:
