Cleaning up our act

Published:  20 April, 2016

Dr Neil Watson explains the benefits of water treatment in reducing energy consumption and contributing towards decarbonisation

In a typical UK household, more than half the money spent on annual energy bills goes towards heating and hot water, according to the Energy Savings Trust.

Boilers account for 83% of household energy consumption and make up 55% of what consumers spend on energy at home. Approximately 60% of carbon emissions are generated by the domestic boilers we rely on to generate the heat to keep us warm and our showers hot.

Given the Office for National Statistics’ figure of 27 million households in the UK, this has to be a primary area of focus if the government is to achieve its objectives of decarbonising energy systems; improving domestic energy efficiency; and reducing the 4 million households in fuel poverty.

Every little counts

As failures in the Green Deal highlighted, this is a vast and complex challenge. There are no simple solutions when it comes to transforming the performance of what has been identified among the least energy efficient housing stock in Europe.

However, significant returns in reducing carbon emissions, domestic heating energy consumption and associated energy bills could be achieved through the introduction of regulated best practice central heating system maintenance using effective magnetic filtration for new build and retrofitting existing systems; premium system inhibitors; and annual water tests.

Taking simple steps like installing a magnetic filter and effective chemical water treatment to ensure boiler efficiency is maintained as part of an ongoing programme could have a significant impact when it comes to reducing energy consumption and saving money on energy and maintenance bills. 

Black iron oxide sludge can cause noisy boiler operation, radiator cold spots, low heat levels, slow operation, leaking valves, deteriorating performance and ultimately the breakdown of the system.

Even if a new A-rated boiler is fitted to an existing system that hasn’t been cleaned thoroughly, and is contaminated with sludge as a result of natural corrosion, its efficiency will quickly deteriorate by as much as 12-15% in a matter of weeks.

According to research, just 5kg of sludge in a system, which is not uncommon, reduces radiator heat output by up to 36%. To recover lost heat, householders turn up the thermostat or use secondary heating sources, resulting in higher energy use, to treat the symptom, not the cause. Employing magnetic filtration technology provides a straightforward, cost effective solution.

Installing an effective filter, which can remove virtually 100% of suspended black iron oxide from the system, in just one million UK households could save in the region of 225,000 tonnes of CO2 annually. That’s equivalent to removing 72,000 cars off the road at a fraction of the cost of the previous boiler scrappage scheme.

The most effective filters have been independently proven to save up to 6% on household carbon emissions and energy bills year-on-year. Energy Saving Trust also estimates that using a premium inhibitor can increase boiler efficiency by 3% and prevent up to a 15% reduction in the effectiveness of radiators bringing further significant contributions.

Legislation

A simple means of ensuring long-term boiler efficiency is to adopt a compulsory annual water test. This would confirm if the inhibitor level in the system is adequate and form part of the overall best practice approach which could contribute to an energy saving of up to 15% a year and help extend the life of a domestic boiler beyond the 12-year lifespan.

Landlords already have to conduct a mandatory annual boiler safety check, so an additional water test taking a couple of minutes while on site, imposes no additional burden or call-out cost. The Heating & Hot Water Industry Council (HHIC) is considering such a development in conjunction with its existing Benchmark scheme.

Similarly, the UK’s 1.6 million annual new boilers installs could be legislated for in a similar manner through a much-needed bolstering of Part L of the Building Regulations. To take it a step further, government funding could be tied to regulation to maintain a constant level of boiler efficiency throughout the life-time of the system.

HHIC is proposing that on installation of a new boiler, installers dose the system appropriately indicating precisely which products have been used. They then test the system water and check it against the calibration chart for known inhibitor concentrations. For each subsequent annual check, the installer would be required to carry out a further system water test to confirm that the inhibitor level remains adequate. If not, a further top-up dose will be required.

Every fifth year, the Benchmark form would state that an additional inhibitor dose must be added to the system and that this should be the same product used at the time of installation to avoid incompatibility issues. Every tenth year, there will be a requirement to cleanse the system thoroughly and re-dose with inhibitor.

While it won’t deliver the total solution, it addresses the long-term efficiency of the boiler and system as a whole and it does so in a practical and cost-effective way.

Dr Neil Watson is global technical director at water treatment manufacturer ADEY

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