Hotting up on bespoke rig technology

Nick Stevenson of Keston Boilers explains why custom-made, prefabricated multiple-boiler rigs are the latest must-haves in commercial heating refurbishments.
The manufacture of prefabricated, made-to-order boiler rig systems offer consultants key benefits for heating refurbishment projects, including speedy installation time, plant flexibility, made-to-measure heat output capacity, energy-efficiency and a transparent specification. Core to attracting consultants to rig technology, is the imperative advantage of meeting the demands of contractors and installers too. The needs of each individual party are carefully considered in bespoke heating, which plays a vital element to keeping abreast of the HVAC industry, as well as developing and maintaining loyalty amongst core customers.

Consultants need a quick turnaround time and no surprises. Commercial buildings such as hospitals and schools need quick installations, allowing for all refurbishments over a very limited period in order to minimise any potential disturbances to classrooms or patients alike. Speeding up the site time by fully understanding how much plant room space is available, and economising on it vigilantly with high tech equipment, means the difference between consultants meeting deadlines or leaking over into the client’s operating hours. Consultants also want to be assured that the units in the rig are fully condensing, Part L compliant, fully modulating, and are controlled correctly to maximise efficiency and use minimal energy.

The prefabricated units enable the consultant to see the actual design of the rigs before manufacture begins. This allows them to negotiate the layout of the site with ‘blueprint’ CAD drawings of the rig, and develop an educated and practical solution in collaboration with the manufacturer. In addition, carefully negotiated floor layouts also provide the contractor and installer with reduced site time, while the system’s easy ‘plug ’n play’ operation allows for straightforward installation.

The fully prefabricated plant and flexible flueing options allow for swift positioning, gratifying the demands of the commercial buildings that set tight deadlines for refurbishment or upgrade projects. The system design is compact and completely pre-plumbed, pre-wired and pre-piped for maximum ease of use. As attractive to consultants, is the rapid turnaround and delivery time, usually within 28 days from date of order.

A-rated, bespoke rigs are the way forward in the condensing boiler world, offering made-to-measure plant individual to each job and specification. With bespoke heating technology, almost any output is achievable and flexibility is paramount. A multiple boiler can incorporate up to five units within a floor standing frame and up to 20 boilers operating in sequence across multiple frames. A dual boiler wall-hung rig is also an option. By creating a system compact in design, more space is freed on site, meaning more opportunity for other plant and, therefore, a more economically viable environment for the end-client.

The most effective maintenance and control programmes should come fitted as standard. To ensure peak performance and optimised output levels, rigs are designed with control panels which can be accessed through remote monitoring. State-of-the-art controls should feature all the bells and whistles required for advanced management, as well as the option for outside temperature sensoring. In addition to the advanced engineered controls, the rig systems are easy to understand and operate, making them highly appealing to service engineers.

Case study

Mount Grace School, Hertfordshire

A prime example of the benefits of rig technology in a commercial environment, and showcasing the positive effects in consultants’ reactions to bespoke heating technology, is the installation of a special Keston Boilers custom-made rig at Mount Grace School in Hertfordshire.

Principal Engineer at Dunlop Haywards Building Consultancy, Robert Earl, approached Keston Boilers to discuss prefabrication of a boiler room for installation during refurbishment of the Technology Rooms at Mount Grace School.

The co-educational secondary school, located in Potters Bar, Hertfordshire, plays host to approximately 800 students and is spread over a total of 17 acres.

The architects’ (Barker & Associates’) scheme for refurbishment of the existing Technology and Craft Rooms included a diverse range of facilities from a new IT suite, through fabric workshops and air-brush facilities, to machine workshops and Forge, in addition to the existing, retained Domestic Science and IT facilities in the Core building.

The consultant wanted to remove the existing gas-fired heating boiler and electric immersion water heater installation of the Core block and replace it with a high-efficiency combined heating and hot water service installation that would offer the School technologically-advanced plant and controls and a cost-efficient system.

He considered that pre-fabrication offered great benefits in terms of programme and quality, particularly so in this case, given the confined space into which the plant would be installed.

Earl wanted a pre-piped and pre-wired rig to incorporate two C55 condensing boilers along with an unvented hot water cylinder, expansion vessels and system pump. The rig needed to be highly efficient and easy to use, and had to feature all the expected requirements of a high quality rig, including SEDBUK A-Rating energy-efficiency, fully modulating, aesthetically appealing and compact design.

He wanted a comprehensive control module with extended options and a header arrangement, to suit either boiler serving the domestic hot water cylinder. To satisfy current technology options, Earl wanted to offer the school the ability to manage the system remotely, via dial-up modem.

Due to certain site limitations, Earl needed a flexible solution with practical flue options for easy positioning. As importantly, the School wanted a system that would offer a return on investment through energy saving. High output at minimal cost and minimal NOx emission.

Several potentially negative factors were taken into consideration, which may have threatened the possibility of satisfying Earl’s request. There was limited plant room space and very little time to complete the project, as students were due to return to school for the new academic year. The consultant required a speedy and professional service that was accurate and offered a high quality solution, first time round.

Keston prepared an outline proposal within 48 hours, based on the given detailed specification requirements.

Where site-handling restrictions apply, the assemblies can be split across multiple frames to client requirements. Larger rigs tend to be floor standing, although dual and triple boiler wall-hung rigs are also available. The rig boilers are generally pre-piped to a single balance header. The special package rig for Mount Grace School included the following elements:

• High efficiency modular condensing boilers, system pump, expansion vessel and all associated components, pre-piped and properly supported in a steel box frame.

• Full and comprehensive controls section, pre-wired and preconfigured to meet all system requirements, a data log and modem connection for off-site monitoring and control.

• Keston Spa stainless steel unvented DHW cylinder, with standby electric immersion element, pre-piped and pre-wired and inclusive of system pressure reducing valve and all controls.

• Factory-fitted diverter valves to enable high temperature DHW recovery, whilst continuing to provide compensated VT heating via non-diverted boilers, with automatic change-over of lead and lag boilers.

After the short contractor tendering period, Keston delivered the completed special rig assembly to site within three weeks. The system was delivered fully pre-assembled and can incorporate all required units, operating in sequence.

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