[Heating Schools Efficiently]
The government's injection of funds into school refurbishment is now coming into effect and actual work on the buildings is starting to take place. One particular aspect which has to be considered for improvement or renewal is the provision of heating and hot water.
The school's refurbishment programme was recognition that a large number of school buildings were in great need of repair and upgrading. Buildings designed 30 or 40 years ago did not give energy efficiency the importance which it now has for both cost and environmental reasons. Insulation was relatively poor and heating systems were very basic compared to the high efficiency systems available today. Indeed replacement of an old basic system with a modern, well designed heating installation may pay for itself in real term fuel economies in as little as 5 years.
Withington Girls School in Manchester, has recently undertaken a thorough review of its heating and hot water provision. With a superb academic record putting it consistently in the top three or four high achievers in the national league tables, the school has a high profile and is a flagship school in Manchester CC education provision. As befits an establishment which has built its reputation for excellence over many years, buildings and services are also expected to be of the highest order.
The existing 30 year old boilers had to come to the end of their life and had been suffering breakdowns which routine maintenance was no longer able to cope with and for which spare parts were no longer available. Being 30 years old, the boilers and heating system had also become outdated, lacking the sophistication of control and energy efficiency now available.
Having maintained the installation for as long as practically possible, on behalf of the local authority, Belfry Maintenance Group recommended replacement and worked with the school, Manchester City Council and the Buderus technical advisory team to design a state-of-the-art, high efficiency installation to replace the first of four boiler rooms. They specified six GB162 100kW output Buderus boilers installed as a multi-boiler cascade system to maximise energy efficiency and to keep fuel bills to a minimum. The system can deliver up to 600kW of heat output.
The compact size and comparatively light weight, at just 70kg, for each of the GB162 boilers ensured ease of handling even where access was restricted. The innovative GB162 cascade design means it is particularly installation friendly, saving fitting time and costs. The boiler connection kit is supplied with all the necessary fittings and accessories so the installer simply builds the framework, attaches the flow, return and gas pipe work, connects the boilers via their individual pump groups. The cascade system is then ready to be connected to the main heating system. Custom-fit insulation is also supplied as part of the cascade kit to ensure heat losses are minimised.
Four GB162 boilers occupy just 1m2 of floor area and provide 400kW heat output. They can be automatically controlled to modulate, and therefore to maximise energy efficiency, for the longest possible period bringing into use extra boilers as and when it is most efficient to do so. It is extremely important that all boilers are specified and installed correctly to ensure they remain in condensing mode for the optimum time which means return temperatures need to be below 50oC. Buderus can provide extensive pre-sales technical consultancy services, including site visits to ensure boilers are properly sized and efficiency is maximised.
The Buderus GB162 is especially suited to installations such as schools and commercial premises where space is limited and a modern heating solution is required. It is whisper quiet in operation and features Buderus's award winning finned aluminium heat exchanger. A unique twisted flow channel brings the maximum amount of water into contact with the hot interior surface of the heat exchanger optimising heat transfer. A thin polymer coating to the outside of the heat exchanger makes it extremely difficult for particles and dust from combustion to adhere to the surface. This effectively makes it 'self cleaning' thereby increasing boiler efficiency and reducing the need for expensive maintenance.
Chris Stevenson, maintenance manager at Whithington School is delighted with the fuel cost savings which he expects to be anything up to 40% compared to the old system. "With the old boilers we had a 150kW output boiler running all day, every school day with no regulation just to provide hot water. This is now provided as part of the complete new system which modulates down to just 19kW to provide only the amount of heat actually needed to meet heating and hot water demand. Controls allow us to programme heating and hot water to the times when it is required and, in addition, the system is zoned so separate areas can be heated for specific requirements, for example the hall and arts centre which can therefore be used by external organisations. As a modern installation, it will also require considerably less maintenance. In fact it is a saving on all fronts."
Belfry Maintenance's Mike O'Donovan adds "The new system will last two or three decades and will deliver tremendous savings. It's already proving much more efficient in performance and is now heating those areas of the school at the far reaches of the system which hardly got warm before. That's down to the system design itself which includes innovative ideas from Buderus such as slow running pumps which ensure heat gets to all the radiators, and specially designed low loss headers and flue system. Even installation was relatively straightforward with compact boilers and a frame system which were assembled on site to make handling easier."
Because of the energy efficiency, the new heating system qualified for an interest free loan from the Carbon Trust and the school is delighted with the whole system from capital cost, operating efficiencies and minimal maintenance to major savings on running costs and much reduced CO2 and NOx emission levels, reflecting the schools policies on the environment.
Everyone's a winner.
