Keeping the lights on
Amidst reports of our increasingly threadbare safety cushion between supply and demand of energy, James Porter, Sales Director at Remeha Commercial, examines the role of the condensing boiler in improving our energy efficiency and helping keep the lights on across the UK.
Scared of the dark? If the thought of the lights going out across the UK makes you nervous, one option is to make sure you have stocked up on candles and torches by January 11, or whenever you read this article. This, according to the National Grid, is the date when the gap between Britain’s energy needs and supply is at its very thinnest. Or, if you want to effect real change, actively avoid wasting energy in the first place. For whilst as we look to generate energy from renewable sources, it is equally important we reduce our energy usage wherever possible. Heating, which is accountable for almost half of a building’s total energy consumption, offers huge potential for efficiency savings. And when it comes to the UK’s large proportion of energy inefficient buildings, high efficiency condensing boilers top the list of practical, cost-effective retrofit solutions for immediate, substantial energy and carbon savings.
Why waste when you can save?
Improving our energy efficiency is pivotal to achieving a more sustainable future. Some 80% of UK properties currently depend on gas for heating with commercial boiler plant providing the heating for a significant percentage of our non-domestic buildings. If the boilers are inefficient, that’s a huge unnecessary waste of energy and finances. The Carbon Trust estimates that organisations stand to achieve energy and carbon savings in the region of 30 per cent simply by replacing any inefficient boilers with high efficiency condensing boilers. This is a conservative estimate: our own data points to savings as high as fifty per cent dependent on the building and the existing heating system in place. With their ultra-low NOx emissions, condensing boilers can also help create cleaner air, reducing allergies and respiratory conditions and improving health and well-being, all of which produces a more comfortable and productive working environment.
Achieving higher efficiencies
Condensing boilers are capable of achieving between 10 to 12 per cent higher efficiencies than non-condensing boilers due to their ability to recover both the sensible and latent heat from the flue gases, energy which is otherwise wasted by conventional boilers. Condensing boilers installed in a well-designed system allow us to use energy more effectively and more efficiently. On a national level, this helps us protect our energy security; for individual businesses and organisations, the relatively low initial investment of condensing boilers combined with lower gas prices offers a fast track to more affordable energy costs.
Smart system design is, of course, crucial to achieving the higher efficiencies. For continuous condensing to take place, the boiler return water must be at or below the dew point of the flue gases, which occurs around 54°C. On older heating systems sized on higher flow and return temperatures (typically 82/71°C), design where possible to promote lower return temperatures or add the appropriate weather compensated controls to maximise continuous condensing and ensure efficient use of the energy input.
Alternatively, perhaps the simplest means of achieving continuous condensing on older heating systems is to install a full-time condensing boiler that, by incorporating passive flue gas heat recovery technology, can recover any waste energy and transfer it back through a Plate Heat Exchanger (PHE) for cold water preheat. This enables full-time condensing boilers to operate at 100 per cent efficiency regardless of flow and return temperatures or boiler load.
Consider also installing multiple boilers in cascade operation and adding a sequential control. Operating multiple boilers in sequence facilitates wider output modulation, allowing the boilers to match more accurately the heat demand of the building. The boilers therefore operate more efficiently and for longer, resulting in maintenance and operational cost savings.
Plant rooms come in all shapes and sizes and their irregular features can present a challenge when it comes to system design – which can in turn have an impact on the budget. Well-designed cascade systems offer contractors a number of design installation options to accommodate these restrictions. A more recent innovation is the bespoke rig system service introduced by enlightened manufacturers to support consultants in overcoming plant room limitations and tight deadlines. These rigs are designed and manufactured to meet the exact requirements of each individual project so that they can be installed in a fraction of the time. This solution is particularly beneficial for organisations restricted to a small window of time in which to carry out refurbishment projects.
Heating for the future
Whether the sole provider of heat or installed as a backup alongside renewable energy technologies such as gas absorption heat pumps and Combined Heat and Power (CHP) units, condensing boilers offer a practical, affordable, flexible solution to cleaner, energy-efficient heating today and tomorrow.
The government has identified gas as an important source in our future energy mix. Condensing technology allows us to use this clean burning fuel more effectively and sparingly to achieve lower greenhouse gas emissions, significant energy and cost savings, and improved energy security. As pioneers of condensing technology, we at Remeha Commercial look forward to working alongside consultants and contractors to support organisations with reliable, cost-effective, energy-efficient solutions that will play their part in keeping the lights on this winter.
This article originally appeared in Modern Building Services magazine
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