Bring on the new generation of compact, lightweight, commercial condensing boilers, shouts Yan Evans (below), technical director, Andrews Water Heaters and Potterton Commercial
THE UK heating and ventilating market is at the forefront in the drive towards improving the energy efficiency of buildings.

The development and wide spread use of condensing boilers, the recent introduction of renewable and sustainable technologies and improvements in energy efficient building design and materials such as insulation, are clear indications of the changes being made.

Every aspect regarding the provision and management of the energy needs associated with the occupation and use of buildings has been and will continue to be analysed, to ensure the achievement of the challenging efficiency and emission control targets of Europe-wide initiatives and legislation.

One result of improving a building's energy efficiency is a reduction in the fuel consumption, whether brought about by the use of renewable or sustainable technologies to provide water and, sometimes, space heating or as a result of improved insulation. It is perhaps not surprising that, to meet this reduced demand, a new generation of compact, lightweight, low output commercial condensing boilers has evolved.

Team work

These developments, with traditional and renewable or sustainable technologies working in harmony to meet building heat load requirements, are very important in the context of the overall vision of the EU energy policy. A key vehicle to the delivery of this policy is the Eco-design of Energy-using Products Directive, increasingly being known as the EuP Directive. This will require all elements of a heating system - the boiler, cylinder, pump and controls - to be assessed together for performance labelling, rather than individually.

This raises the possibility that the subsequent replacement of one component part may affect the overall performance of the system. Consequently, the working relationship between a building's boiler and its renewable or sustainable heat source system will become an interdependency that may be best served by a complete, all-in-one, package solution.

Measuring up

Consider, for example, a light commercial sheltered accommodation application, made up of 30 single occupancy flats, that uses combined, decentralised power and heat generation technology to meet its requirements.

The electricity output meets the internal needs of the building, including pumps, communal areas and lighting - the buildings base electrical load. The heat requirement is for hot water and space heating. The size of the CHP unit required is assessed on the summer, or base, demand to ensure the maximum unit running hours throughout the year. Any electricity requirement in excess of the CHP unit capacity would be met from the national grid, with any additional heat demand being met by gas condensing boilers.

To meet these demands, a Dachs mini-CHP could be specified, with an electrical power output of 5.5kWe of 3-phase electricity at 415V, 50Hz and a thermal output of 12.5kWth. The unit, powered by an internal combustion engine fuelled by natural gas, would operate for approximately 5,000 to 6,000 hours per annum if sized correctly to meet the buildings base thermal load. The CHP unit would act as the lead boiler, supported for example by a Sirius MB Series 220kW gas condensing boiler solution from Potterton Commercial. The Sirius MB Series is a complete heating system including boiler, pumps, pressurisation system and heating controls. The modular construction of the system ensures ease of access, and enables the system to installed in-line or with a corner configuration.

The Dachs mini-CHP unit, exhaust condensers, buffer vessel and the MB Series condensing boiler system would be provided together as a complete package. This total solution approach enables the performance level of a system, once assessed, banded and labelled as will be required under the EuP Directive's projected requirements, to remain unaffected following component renewal.

Togetherness

The interdependency of the various elements of a commercial building's energy using systems when complying with the performance assessment requirements of the EuP Directive that will soon come into effect, points clearly towards the advantages of the total plant room solutions.

This would particularly apply where the energy is being delivered by a combination of different technologies, necessary to achieve the EU energy policy efficiency and reduced carbon emission
targets.