Energy efficiency

Energy efficiency

Harris, Phil

One of the biggest factors impacting upon the design of new buildings is energy performance. Architects increasingly face tough decisions when it comes to designing an environmentally-friendly building that can offer practical, long-term benefits. A growing number are turning to thermal mass solutions in order to create energy-efficient buildings for the future.

The design of buildings has undoubtedly gone through a revolution over the past decade and the environment is now regarded as a key priority for both owners and developers. However, one key factor is often overlooked -. the need to provide a ‘future-proof development. Warmer summers, coupled with increasingly unpredictable weather, are often attributed to the effects of global warming. If these current trends continue, many existing buildings will become untenable. When it comes to the design of new buildings, failure to consider these factors could significantly reduce a building’s overall lifetime.

Reduction of energy consumption

The introduction of Part L of the Building Regulations has placed greater emphasis on the need to reduce energy consumption used in a development. Some experts in the industry have predicted that the revised guidelines for Part L, which are set to be introduced in 2006, could add up to £10 per m^sup 2^ to the overall building costs of a new development. Under Part L, new buildings must offer guarantees on the levels of insulation provided. When insulation increases, it then becomes necessary to provide improved ventilation in order to control carbon dioxide levels, remove pollutants and prevent overheating within the building. Inadequate ventilation will have an impact on the air quality, making it difficult for a building to achieve the Government’s recommended guidelines on air quality of eight litres of fresh air, per person, per second.

In addition to providing a well-insulated environment, many architects are actively working to obtain increased levels of energy performance from their buildings. It is a growing trend, with a number successfully integrating ‘green’ features in the design of new developments. The Eliot Park Innovation Centre, (EPIC Centre) based in Warwickshire (see Figure 1), for example, combined a thermal mass heating and cooling system that exploited the energy transfer through its concrete floors, with more traditional solar panels. The result was not only an aesthetically attractive building, but one that is capable of offering longterm energy savings. The success achieved at Eliot Park is an example of how the concrete industry has responded to the market challenges through innovation. Many organisations working across the industry have successfully developed practical ways of providing ‘future-proof concrete solutions, specifically designed to enhance the energy performance and air quality within a new development.

Concrete flooring

Concrete flooring forms an important part of the energysaving provisions within a building. A number of products ranging from suspended flooring systems featuring precast concrete T-beams in-filled with polystyrene panels, to aircrete beam and block flooring systems, have been successfully applied to many developments in the residential sectors. With the commercial sector in hot pursuit, we can expect to see concrete-based solutions play an increasingly important role in the provision of energy-efficient solutions. In addition to flooring, concrete is also being successfully used to offer a complete building solution. Demand for systems like TermoDeck has also grown rapidly, and with increased pressure from the environmental lobby, there is little doubt that we will see many more buildings across the UK exploiting thermal mass.

Exploitation of thermal mass

Introduced into the UK over a decade ago, TermoDeck is an exciting concept, and one that is growing in popularity across Britain. Among the many TermoDeck projects is the University of East Anglia’s Elizabeth Fry Building. The development proved to be so successful that the UEA now benefits from four TermoDeck buildings and has recently commissioned a fifth. Originally developed in Scandinavia in the 197Os, TermoDeck is a unique building system. The concept is based on exploiting the natural changes in heating and cooling, which occur in the thermal mass of a building, allowing a stable temperature to be maintained internally. During summer months, cooling is achieved by circulating fresh air overnight with little need for additional energy input (see Figure 2). At commencement of business the following day, the temperature of the building fabric is able to sustain prescribed internal conditions with minimum energy use during occupation. In the winter, this process is reversed, ensuring that the building benefits from a stable temperature throughout the year.

An additional benefit of the system is that it eliminates the need for radiators, allowing any development using the system to benefit from considerable space saving throughout a building. Carbon dioxide levels are significantly reduced, helping to provide an environment that allows users of a TermoDeck building to receive a constant source of fresh, filtered air, helping to improve concentration levels, and allowing users of the building to remain alert for longer periods. Operating through the thermal mass of a building, TermoDeck can be easily integrated into almost any type of development during the design stage. With its energy saving and full fresh air, the system has been successfully applied to many different types of structures ranging from schools and universities to office developments and even arts centres. More recently, TermoDeck has proved to be a popular choice in courtrooms.

The East Anglia Law Courts (see Figure 3), situated on sites at Ipswich and Cambridge, are two of a number of court buildings in the UK that were built using the TermoDeck system. Completed in 2004, research by facilities managers at the courts revealed that by including TermoDeck, the two buildings had successfully achieved an overall reduction in energy consumption of 50% during their first year of operation, compared with traditionally ventilated equivalents. Developers using TermoDeck can offer clients a practical, future-proof solution that will help to meet the needs of the construction industry for many years to come.

Concluding remarks

There is no doubt that concrete is playing a vital role in the creation of energy-efficient buildings, but given the growing pressure placed on architects to deliver greener, energy-efficient buildings, it is vital that the industry as a whole seizes this opportunity to create long-term solutions to our changing environment. Concrete buildings should not therefore be seen as simply a cost-effective solution that can create new developments quickly, but as a long-term solution that will remain future-proof for many years.

PHIL HARRIS, TARMAC TOPFLOOR

Copyright The Concrete Society Nov/Dec 2005

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