Saving energy with biomass boilers

Saving energy with biomass boilers

Biomass boilers provide a sustainable heating solution for homes and commercial premises, explains Anna Wakefield, Marketing Manager for Grant UK.

There is no doubt that the cost of heating our homes and businesses remains a major issue across the UK. Indeed, it is likely to be a key point of debate in the run up to the general election early next year. With energy bills so high and in anticipation of further increases in the price of fossil fuels, offering your domestic and commercial customers biomass boilers is a realistic and attractive proposition.

The Microgeneration Certification Scheme (MCS) approved Spira condensing wood pellet boiler range utilises our patented stainless steel Vortex turbulator baffle arrangement and have a rapid ignition system with modulating burner. This means our boilers operate in much the same manner as a standard gas boiler to give you a greater degree of control of your energy output. Importantly, it require little maintenance, featuring a self-cleaning design and automated fuel feed so the need for users to intervene is kept to a minimum.

The Spira wood pellet boilers are at present the only MCS registered condensing self-cleaning pellet boilers on the market with a 97% seasonal efficiency (SAP 2005), and are eligible for the Renewable Heat Incentive (RHI). Launched in April 2014 the RHI financially rewards householders for generating and using renewable energy to heat their homes. On a quarterly basis (for 20 years from the date of installation, but paid over a 7 year period), the domestic RHI will pay a tariff of 12.2p per kWh for biomass boilers.

To access RHI payments both installers and products have to be registered with the Microgreneration Cetification Scheme. Installer certification includes assessing the supply, design, installation, set-to-work, and commissioning of renewable microgeneration technologies.

Similar to the Gas Safe Register, the MCS gives installers a mark of quality and demonstrates to the consumer that the installation will be completed to the highest standard every time. We run our own Accredited Installer Scheme, called G-One, as well as free of charge product courses at our Training Academies in Devizes and Hawes.

So how does biomass boiler technology work? Biomass boilers are fuelled by wood, and so burn wood pellets, chips or logs to provide an environmentally friendly and convenient way of heating a building, whether a home or commercial building. The fuel is made using waste products from sawmill industries or wood from managed forests (where trees are planted to replace the ones cut down). Increasingly, the most popular type of biomass boiler burns wood pellets.

In the case of wood pellet boilers, they are generally a little larger but have a similar output to traditional fossil-fuelled appliances. Like oil boilers, biomass boilers are more commonly used in off-gas rural locations. They require a large hopper to store fuel and so are usually installed in a garage, store or outhouse.

Wood pellet boilers use advanced controls, which regulate the amount of fuel being fed to the burner to match the heat demand of the boiler. The fuel is fed to the burner via an auger connected to the adjacent pellet hopper. This can, in turn, be automatically supplied from a bulk pellet store, which can vary in size.

On start up, the auger feeds the wood pellets from the hopper into the burner where they are lit by an ignition element. The burner output modulates to achieve the set temperature by controlling the feed rate of pellets. The fan in the burner propels hot gas generated from the fuel into the product’s primary heat exchanger. The heat energy is then transferred to the water circulating around the radiators or underfloor pipework of the heating system.

While many modern pellet boilers will lose up to 20% of the energy produced through waste gases exhausted by the flue system, appliances such as the Spira are condensing and have a secondary heat exchanger, designed to capture some of this lost heat energy.

When looking for a suitable site to install a wood pellet boiler, it is important to ensure you have enough space for the appliance and storage of the fuel. A bulk storage system can be used for greater pellet capacity and if auger fed, needs to be sited close to the boiler. Alternatively, for installations where an auger fed hopper arrangement is unsuitable due to space restrictions, a vacuum system can be used.

The room, in which the boiler is installed, also requires sufficient ventilation to ensure an adequate air supply. It allows the appliance and flue to operate safely and efficiently and can be easily provided by a correctly sized permanently open air vent.

Wood pellets are available from a number of manufacturers and specialist suppliers in the UK. Also, some of the larger Plumbing and Heating merchants are now stocking wood pellets. They can be bought in bags of varying sizes or delivered in bulk by tanker, which is the most cost effective option.

Wood pellet boilers produce ash and do require cleaning and maintenance, however the very best wood pellet boilers, such as the Spira now have a self-cleaning function which, when used with EN Plus A1 grade pellets with low ash content, reduces the need for regular maintenance.

Grant UK also offers support for end users of biomass and its other heating technologies in the form of “Living With” guides, which can be downloaded from this website and presented by installers once the boilers are ready for use. These simple, easy-to-follow guides help end users to look after their technologies and explain how they work. Grant’s You Tube channel also provides further support to plumbing an heating engineers and features ‘how-tos’ on many of our products for installers to refer to.

In conclusion, biomass boilers provide a realistic, sustainable and effective solution to heating homes and businesses. With the right training and support from forward thinking manufacturers, and heating engineers can access this growing market.


Saving energy with biomass boilers
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