The scope and benefits of packaged plant rooms

Schematic
The speed and efficiency of installation is greatly improved by the use of 3D modelling and is brought to full potential by off-site manufacture.
Manufacturing plant rooms off site offers a range of benefits, which are increasing all the time — as STEVE COOPER explains.In recent years, the use of off-site manufacture for building-services plant has been extended to encompass the construction of complete plant rooms in the factory environment. Demand for packaged plant rooms that can be delivered to site requiring only final connection is steadily increasing — both in the UK and overseas. But what is the scope of this approach? Which projects can or cannot be completed in this way? How can the benefits be quantified? Scope and limitations As one might expect, there are some dimensional limitations related building plant rooms off site, but much more can be achieved than initially thought possible. For example, Armstrong Integrated Systems offers plant rooms that measure up to 50 by 12 m in size. While it is perhaps unlikely that such a large structure would be required by a customer, we have already built and installed several plant rooms measuring over 25 by 12 m, and these dimensions lie well within the scope of off-site manufacture. The key constraint, of course, is the logistics behind transporting the completed structures by road. To make this possible, the plant room is purpose-designed, enabling it to be built in sections up to 4 m wide (the maximum width for safe and legal road transport). The sections are simply connected together once they arrive on site. When selecting components for the system, off-site manufacture of the plantroom is unlikely to impose any technical limitations. Generally, the components are specified in exactly the same way as for installation by traditional methods. However, design has been greatly enhanced in recent years by the latest 3D modelling technology. For example when creating a plantroom for a customer, we draw on a large library of computerised 3D graphic models of pumps, chillers, boilers and other system components, from a number of manufacturers. This enables accurately-scaled graphics of components to be manipulated and ‘connected’ on screen to create a simulation. As a result, it is much easier to explore value-engineering opportunities, such as ways of reducing pipework, streamlining assembly or incorporation of the latest HVAC technology for improved lifecycle costings. All parties involved in the project have the advantage of being able to ‘walk-through’ the plantroom if required with the help of the on-screen simulation. The speed and efficiency of installation is greatly improved by the use of 3D modelling and is brought to full potential by off-site manufacture. Any mismatching of components, pipework or connections can be identified far more effectively when the system can be seen in accurate 3D, addressing potential delays long before the equipment arrives on site. Importantly, as the entire plantroom will come from one supplier, there is only one consistent 3D model and one channel of accountability. The plantroom is also tested at the factory prior to delivery. Benefits of off-site manufacture In its M & E datasheet reference ACT 5/2002 4.1, BSRIA provides an excellent overview of the benefits of pre-assembled plant and plantrooms. The major advantages stem from the fact that a construction site is seldom the ideal place to assemble a plant room — any more than the hard-shoulder is suitable for the manufacture of a car. In contrast, building in the factory enables the optimum assembly environment to be created and replicated with each project. This removes the ‘unknowns’ associated with on-site construction, thereby reducing the risk of costly delays, waste and rework. There are no hold-ups due to bad weather, and the plant room can be built concurrently with other works rather than having to wait until other parts of the project are completed. Installation can be scheduled into the project with far less complexity and very little dependence on other factors. In addition, of course, as the plant room only requires final connection, installation times are greatly reduced. BSRIA states that site installation time can be reduced by up to 90%. A particularly important benefit is, of course, reducing health and safety risk. In a factory, equipment can be assembled on modular bases with open access on all sides and overhead lifting equipment for large components. It can be very difficult to achieve this level of control over health and safety risk on a construction site. In addition, the frequency of deliveries of equipment to site can be minimised to reduce environmental impact. Specifiers often believe that off-site manufacture will add cost to a project. However, a detailed case-study carried out by BSRIA demonstrates significant savings arising from packaged plant rooms. The case study involved the installation of two pre-assembled packaged plant rooms on the roof of a 6-storey office development in West London. The total installed cost comparison takes into consideration nine key cost elements relating to a project of this type. Whilst plant and material costs are the same for both approaches, reductions in other areas of expense show an overall 13.4% time/cost saving made possible by off-site manufacture. To be considered are the reductions in site costs relating to accommodation and secure storage of system components, and on-site project management. Also to be accounted for is the removal of the risk of a programme overrunning and the benefits of a zero-defect installation. As manufacturers of pre-assembled plantrooms have expertise in the latest manufacturing and production engineering techniques, the assembly phase can be carried out in the factory under close scrutiny utilising formalised processes, resulting in a higher level of quality in the finished plant room. This can be expected to result in a fast, trouble-free installation and commissioning phase. Packaged plant rooms — the future I believe the key to the future for packaged plantrooms is the ‘repeatability’ offered by construction in the factory environment. Each construction site creates a different set of circumstances. However, in the factory, conditions can be replicated for each project. This provides a framework for continual improvement of quality and manufacturing efficiency. Studying each project, and implementing improvements into future projects, is central to finding faster and more effective manufacturing methods. Ultimately this can drive down leadtimes and lead to steadily improving levels of quality for the finished product. At Armstrong Integrated Systems, for example, we have implemented production efficiency techniques developed by world-class manufacturers to drive these improvements forward. Initially, we took the Key Performance Indicators made available by BSRIA for M&E contractors as a basis for measuring the effectiveness of our operations. In recent years, we have been able to achieve and exceed these performance levels and are now setting new internal benchmarks for ourselves based on even more ambitious targets. As time progresses, we expect these improvements to make the quality and cost benefits of off-site manufacture all the more compelling in the eyes of specifiers. In summary, pre-assembly of skid-mounted plant has proved to be a welcome innovation. Off-site manufacture of plant rooms is now carrying this innovation to its natural conclusion and delivering valuable and, indeed, measurable benefits for the speed and efficiency of projects. Steve Cooper is managing director of Armstrong Integrated Systems Ltd, Mucklow Hill, Halesowen, B66 8DJ.



modbs tv logo

New Sustainability Director for Wates Group

Wates Group, a family-owned development, building and property maintenance company, has appointed Cressida Curtis as its new Group Sustainability Director.

Domus Ventilation appoints new contractor sales managers

Ventilation systems manufacturer Domus Ventilation has announced the arrival of three new Contractor Sales Managers.