Education Business

For the vast majority of educational buildings, even relatively new ones, heating costs are one of the highest overheads related to running the buildings. In looking at how they can improve energy consumption and costs, as well as reducing their carbon footprint, many such organisations have opted for wood-burning, biomass boilers from Hoval.
    
A case in point is Pontllanfraith secondary school, where Caerphilly Council has replaced four old coal-fired boilers at with three UK-manufactured 350kW STU wood-burning boilers from Hoval. Contractors Lorne Stewart also installed new stokers and feeders, enabling the pellets to be fed automatically to the boilers to provide precise control of heat output. The boilers are linked to a control system which brings them on in sequence as and when required.
    
The wood pellets are derived from sustainable sources and the carbon dioxide they produce during combustion is equivalent to that consumed by the trees during growth, making them carbon-neutral. A further benefit to the council is an increase in energy efficiency.
    
“Although wood has a slightly lower calorific value than coal, the new Hoval boilers are more than 90 per cent efficient, compared to the 68 per cent efficiency of the coal-fired boilers, so we are achieving significant improvements in efficiency,” commented John Davies of the council’s Property Service’s department.
    
The pellets are stored in the existing coal bunker, which has been refurbished and waterproofed to make it suitable for wood storage. From here, the pellets are fed automatically to the boilers so that no human intervention is required.
    
A further benefit of wood burning boilers is that less maintenance is required, compared to coal-fired boilers, and the ash (potash) can be used as fertilizer if required.
    
Nottinghamshire County Council (NCC) has adopted a similar policy for many of its schools, either replacing old boilers with biomass boilers or converting existing coal boilers to burn wood pellets. “We were the first local authority in the country to gain a Public Service Agreement with central government to fund projects based on reduction of carbon emissions, which helped to fund the capital investment”, explained NCC’s Energy Manager Alan Allsopp.
    
A new school and two existing schools in Northumberland have also recently installed Hoval biomass boilers, replacing gas-fired boilers in one case.

Ultra-efficient condensing boilers
Biomass boilers are not the ideal solution for all projects, so when conventional boilers are used it’s important to select the most efficient available, such as Hoval’s Ultragas condensing boilers.
    
At Braintree College in Essex, for example, replacing three existing boilers with three Hoval 500kW Ultragas condensing boilers has reduced fuel consumption for heating by 40 per cent, as well as reducing maintenance costs and creating more space in the boiler room.
    
Ultragas boilers were selected by consulting engineers Atkins Management Professional Services: “Having carried out a feasibility study we decided there were significant advantages to the Hoval Ultragas condensing boiler and this was obviously the best boiler for the job,” said Adrian Sharp of Atkins. “We also visited a school that was already using these boilers and their experience confirmed that decision,” he added.

Working together
There are many situations where the greatest energy and carbon savings will be achieved by integrating different technologies, such as biomass and condensing boilers – possibly including other renewables such as solar heating and heat pumps. For instance, condensing boilers are most efficient when the water returning to them from the heating system is at a relatively low temperature. So in some projects the best solution may be to use biomass boilers for hot water, and condensing boilers for the central heating.
    
In other situations, as noted above, it may be possible to include other renewable energy sources – such as solar heating. Solar heating is particularly good for swimming pools where there is a constant demand for heat. It can also be used for hot water, providing all the required heat on sunny days and pre-heating hot water when less solar energy is available so the boilers use less energy getting the water up to the required temperature. Similar savings may be achieved through heat pumps, which are able to extract heat directly from the ground or from the outside air, even on cold days, and with very little energy consumption.

Making it work
With all of these options available, one of the biggest challenges is to get the different technologies to work together. As one of the few companies to offer condensing boilers, biomass boilers, solar heating and heat pumps, Newark-based Hoval has extensive experience of integrating diverse heating systems. To that end, the company has developed a sophisticated controls package that can ensure each system is used to maximum potential and, therefore, that energy savings are maximised as well.

For more information
Tel: (01636) 672711
Fax: (01636) 673532
Email: This e-mail address is being protected from spam bots, you need JavaScript enabled to view it
Web: www.hoval.co.uk