PROJECT: Robinsfield Infants School
The pupils, teachers, class room assistants and support staff at Robinsfield Infants School remained nice and warm during the recent cold snap thanks, in part, to the installation of three brand new Remaha 110 ECO 115 modulating gas fired condensing boilers offering a total of 321kW of heat energy.
Catastrophic failure of the cast iron sections in the old boilers meant that replacement was a matter of urgency. The new boiler installation was designed by Westminster City Council Engineers, the design specification was to ensure that the heating load requirement of 180kW was met at all times. The installation of a third boiler offered a contingency of 107kW, ensuring that the full load could be met should one of the boilers fail in service. Local services to the boilers, control system, gas supply, LTHW flow and return and exhaust gas flue were to be designed by the installation contractor.
Westminster City Council sent out notice for suitably qualified contractors, through CompeteFor, to tender for the boiler replacement contract. Artic Building Services was the successful bidder and the contract was duly awarded. The work involved decommissioning and stripping out of the existing boilers, the local LTHW flow, return and gas pipe services. The existing flue was unsuitable for the new boilers as was the existing gas supply and so both had to be replaced.
Following an extensive site survey Artic Projects Division set about the design process. Access to the basement boiler was limited, however Artic Building Services overcame these difficulties and work commenced with the construction of a new boiler plinth large enough for the three new boilers. The new boilers were installed and the process of installing the new flue and pipework began. The stainless steel flue had double rolled joints suitable for the containment of the condensate formed as part of the combustion process. New combustion fan assisted air ductwork was finished with fixed blade aluminium grilles. The new gas main was installed, complete with individual in line safety solenoids, for each of the boilers.
For the LTHW pipework and pumps fresh connections were made from the new reverse return header to connect to the existing primary flow and return pipework system. A dosing pot, missing from the original boilers, was added across the primary flow and return pipework. New thermal insulation to the LTHW pipework, which consisted of sectional glass fibre lagging with an over covering of lightweight PVC film, was applied.
Following pressure testing of the gas main and branch services from the gas meter a compliant gas safety certificate was issued. The final stage of the project was a thorough testing of the new control system, the performance of the boilers and a water treatment analysis. Once the Operation and Maintenance manuals had been written to incorporate the new control system the project was handed back to the customer to complete satisfaction.