To retrofit or not to retrofit – why the question?
James Porter, National Sales Manager at Remeha Commercial, looks at the significant energy and carbon saving benefits to be reaped from a simple, cost-effective heating retrofit.
That it was a cold winter is in no doubt, with March the UK’s second coldest since 1910. Nonetheless, weather adjustments aside, it is disconcerting to learn that the UK’s greenhouse gas emissions in 2012, far from reducing, have actually increased by 3.5 per cent from the previous year according to a recent report published by the Department of Energy and Climate Change. More concerning still is that if we consider carbon dioxide alone, the main greenhouse gas, emissions have actually risen by 4.5 per cent.
One of the biggest challenges faced by businesses today is meeting the Government’s target of reducing our greenhouse gas emissions by 80 per cent by 2050. According to the Building Research Establishment (BRE), the energy used by non-domestic buildings accounts for approximately 18 per cent of the UK’s carbon emissions, so these buildings represent a real opportunity to achieving this goal. When we consider that heating and hot water generation alone account for nearly half the UK’s energy consumption and around 40 per cent of the greenhouse gas emissions, it makes sense for organisations to look at ways of improving the energy efficiency of heating in their buildings. This will, after all, bring energy savings which will translate into reduced greenhouse gas emissions and lower operational costs.
New buildings are designed around low- to zero-carbon heating. The problem we face in the UK is that our buildings are some of the oldest in Europe, many with hugely inefficient old heating systems in place that guzzle energy, wasting heat up the chimney. Indeed, according to a report by BRE, some 60 per cent of our existing commercial buildings will still be in use in 2050, so refurbishing these buildings is crucial if we are to meet our greenhouse gas reduction target.
Retrofit might not be the most attractive proposition for a business operator, but in old properties the structure of the building and the existing heating system restrict the variety of energy saving options: installing a renewable energy technology into a new system is simply not possible. In such cases, retrofit is often the only answer, offering a number of ‘green’ heating solutions, all of which if adopted will bring significant energy and carbon savings.
The first option is to upgrade the existing boiler to a modern, high efficiency condensing boiler. Boiler technology has advanced considerably with the result that today’s fully modulating boilers offer high efficiencies and clean combustion for green operation. As a general recommendation, any boiler between 10 and 15 years old should be replaced with a modern condensing boiler, however many buildings still have old atmospheric boilers in place, consuming and wasting even greater amounts of energy. In such cases, upgrading to one of today’s cleaner, greener models could not only halve fuel bills but also reduce the level of greenhouse gases by at least 90 per cent. Where heating is concerned, we manufacturers focus on cutting not just carbon but also NOx, a gas that is produced during high temperature combustion and has far greater global warming potential, according to the Environmental Protection Agency.
Retrofitting a modern condensing boiler is a relatively cost-effective measure which will bring rapid financial payback and immediate energy savings. Disruption and downtime during installation is minimal as new models are designed to be smaller and lighter to make fitting quicker and easier. Manufacturers have introduced models which can be dismantled for projects where access to the boiler house is problematic; others are supplied on wheels for improved manoeuvrability. Cascade and rig systems also facilitate faster installation. At Remeha Commercial, we now offer a bespoke rig system design and manufacture service; this not only offers greater flexibility of floor planning design to match more accurately the required heat output demand, but it also improves quality control and efficiency levels as the whole system, rather than the individual boiler, is delivered pre-assembled and pre-tested on site.
Controls are the next option. Adding the appropriate controls to a boiler will allow it to operate at its maximum efficiency level, helping the system use less energy and reducing greenhouse gas emissions. We recommend that the minimum control strategy should encompass valved zone control, thermostats and timers. Further improvements and energy savings can be achieved by sequential control of boilers, two zoned temperature and time control, and weather compensation.
Perhaps the most exciting – and to my mind the optimal – solution for retrofit projects is a ‘super condensing’ heat recovery system. It’s an unavoidable fact that old heating systems require more energy to heat. Even with high efficiency condensing boilers there can be energy waste of around 20 per cent when boilers are run at high loads and high flow and return temperatures. If it takes more energy to heat an old system, it makes absolute sense to recover this otherwise wasted energy. Installing a ‘super condensing’ heat recovery system into the old system that will deliver 100 per cent efficiency at all times, irrespective of primary circuit temperatures, will do just that, using the recovered energy for the benefit of pre-heating domestic hot water or space heating.
This ability to achieve maximum combustion efficiency of 107 per cent NCV on an old system at 82/71°C through ‘super condensing’ technology is the ultimate ‘green’ retrofit solution. At Remeha Commercial we call this higher attainable level of efficiency ‘Blue Efficiency’.
Whichever the preferred option, retrofitting energy efficient heating into our old buildings will allow us to address the overwhelming national problem of greenhouse gas emissions that old buildings pose whilst also bringing welcome energy and fuel savings on an individual business level.
Retrofitting – surely it’s not a question of ‘why’, more one of ‘when’.
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