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Effective upgrading of heating systems

Published:  07 November, 2008

Graham Williamson
Upgrading a heating system is much more than just upgrading the boiler plant — Graham Williamson.

The heating industry has made a strong response to Government legislation to encourage energy efficiency, and the specification of high-efficiency condensing boilers has steadily increased. However, to maximise efficiencies Graham Williamson, business director of commercial heating at Ideal Boilers, stresses that installers now need to take into account more factors than simply upgrading to a high efficiency boiler.

Undoubtedly, ‘energy efficiency’ has been the phrase on everyone’s lips throughout the heating industry over the last few years. Although the introduction of legislation in relation to energy efficiency has brought added complexities to the market, the industry has responded with the development of new technology to help achieve the targets set and reduce energy costs in the face of rising fuel prices.

Manufacturers have produced a wide range of high-efficiency commercial condensing boilers that both meet and exceed legislative requirements, whilst installers and specifiers are now typically putting energy efficiency as the primary priority in their selection and specification of heating equipment.

Whilst this positive response is to be applauded, such are the environmental and energy-cost pressures facing businesses that installers and specifiers now need to look further than simply recommending an upgrade to a high-efficiency boiler if they are to maximise energy efficiencies and meet future targets.

Quite often commercial and industrial heating systems in UK buildings can be as much as 20 to 30 years old — meaning some cannot easily adopt condensing technology, either through design or suitability. Therefore, to realise the full potential of a high-efficiency condensing boiler, additional factors such as flue terminal position, changes in the water distribution characteristics and, more importantly, controls now need to be considered to overcome any possible challenges and maximise efficiency.

Before specifying a condensing boiler, it is important to take the existing heating system into consideration. In some cases, the existing system may require cleansing and the system water treating before it can be successfully teamed with a condensing boiler. By paying attention to these factors from the onset, we can help prevent premature failure and ensure the boiler can function to its potential.

Flue positions must also be considered. It is essential that existing flues are carefully inspected to determine if they are suitable for teaming with a high-efficiency boiler, as older flue systems may not be impervious to the acidic nature of the flue gases and the high level of condensate that condensing boilers produce within the flue system. As a result, installers need to recognise potentially unsuitable systems and recommend how these can be updated to provide the end user with the highest levels of efficiency.

Controls have a significant role to play in achieving optimum efficiency levels. Unless a high-efficiency boiler is managed and operated properly, the benefits of even the most energy-efficient boiler can be significantly reduced. System efficiency can increase by up to 10% compared to boilers without independent control systems.

To maximise efficiency whilst still meeting the heating requirements of the building, it is important that the flow rate through the heating system is considered, especially if the full potential of the boiler is to be realised. A condensing boiler will only provide its highest efficiency when the system return is below 50°C; unless this is catered for in the system design parameters, the boiler will not necessarily deliver the required benefits. All too often the condensing boiler is installed in a system that operates at traditional temperature differentials such as 82°C flow and 71°C return, so the potential of the boiler is not maximised.

It is often too easy to replace a traditional boiler with a condensing boiler and not give considerations to these essential factors. These considerations will become increasingly important as we see a growing demand for renewable products, as the need to ensure that the chosen heating technology is suitable for the application will be critical in our quest to meet energy efficiency-targets.

Whilst all the tools and knowledge are available across the market for installers and end users to take advantage of high-efficiency options, it is essential that installers review all aspects of each individual application carefully. Doing so will help to ensure that a product is accurately specified and, consequently, offer the most efficient and cost-effective solution for the end user.

Graham Williamson is business director of commercial heating at Ideal Boilers



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