Buderus wall mounted condensing boilers installed on roof of apartment block in Cheshire

(18/05/2010)

Belfry Group Limited of Warrington Cheshire have taken a novel approach to overcoming a problem in designing a heating system for an apartment block in Hyde, Cheshire for new Charter Housing Trust Limited.

The 16-storey building comprises 93 flats, of which, 38 are sheltered accommodation, each with its own hot water cylinder and heating boiler which had become out-dated and inefficient since their installation in a 1993 refurbishment. With environmental considerations now a key factor and anticipating forthcoming HSE legislation to prohibit the installation of individual gas appliances in high rise buildings, an 8-boiler Buderus cascade system was specified to provide a centralised district heating and hot water scheme, together with 20 Buderus solar panels and, for each flat, an individual compact heat distribution unit.

Having established the preferred replacement system, the next problem was where to position the installation as the 1970s building had had no need for a boiler room. Whilst this may seem unusual, the roof was the simple answer.

A specialist metal pod was ordered and fitted out with the cascade of eight Buderus GB162 100kW wall mounted condensing boilers installed in a space saving 4x4 configuration, occupying just 2m2 of floor area.

Keith Rimmer of Belfry Group said: “We chose the Buderus system because it has proved very reliable in previous installations we have carried out and because it is especially easy to maintain. The Housing Trust specifically requested a high efficiency system to minimise carbon emissions and to keep fuel bills as low as possible. The Buderus cascade modulates down to just 19kW and is programmed to operate at maximum efficiency at all times, so we expect very significant cost savings from the heating system. The solar plant is designed to provide the majority of the domestic hot water requirement for around 50% of the year depending on weather conditions. All in all it is a very efficient system.”

The completed pod has now been successfully craned into place, after many anxious references to the meteorological office in order to forward plan the most likely date for suitable weather conditions. All went well with the lift and subsequent completion of connections and the system is now fully operational.

David Rigby of New Charter Housing Trust says “From the Housing Trusts viewpoint, we were particularly keen to reduce the carbon footprint of the building which meant reducing CO2 by choosing a high efficiency system, including solar. Our estimates show the CO2 emissions will be reduced by almost 60% and fuel cost savings for tenants could be as high as 50% - a terrific result for us and our tenants. These figures should make good reading for any other housing association looking for energy efficiency and savings for their properties.”

The Buderus cascade system uses compact and lightweight GB162 condensing boilers which are easy to handle even where access is restricted. They are particularly installation friendly saving fitting time and costs with pre-fabricated connection kits supplied together with all the necessary fittings and accessories, including custom-fit insulation to further reduce heat loss.

In a cascade system, each boiler is automatically controlled to modulate its output to match the heat demand. This encourages lower flow temperatures and therefore improved condensing performance, maximising energy efficiency for the longest possible period. Additional boilers are only bought into use as and when it is most efficient to do so. This reduces wear and tear on the system, and over time helps to lower maintenance costs.

The Buderus GB162 is a versatile boiler featuring finned aluminium heat exchanger technology. This has a unique twisted flow channel which brings the maximum amount of water into contact with the hot interior surface of the heat exchanger to optimise heat transfer. A plasma-polymerised surface on the heat exchanger makes it difficult for the products of combustion to stick to the fins. This improves durability and makes it very easy to maintain. .

The Buderus flat plate solar collectors use ultra-sensitive daylight absorption technology with a highly translucent solar safety glass that maximises the amount of solar energy absorbed even in cloudy conditions. Up to 50 collectors can be installed in a single field with multiple fields possible should demand require it. In particular the Buderus controls platform includes an intelligent solar optimisation function which enables seamless integration between the Buderus solar connectors and Buderus boilers. This is essential to maximise the heat generated by the solar collector field. Buderus SKS connectors are hermetically sealed and filled with dry argon to eliminate mist, condensation or corrosion from airborne pollutants.

The system also benefits from a bespoke Building Management System, designed by Belfry and its sister company Building Software Solutions. The bespoke BMS is linked to heat meters installed with heat distribution units in each flat. This allows Belfry Group to generate reports for the client on energy usage, system fault reporting, and even provide fire protection to each dwelling if required, which is a very important resource for high rise properties.

Related categories:  Boilers - Combination and condensing   Energy Conservation   Solar heating