Project Value: £400K
Project Completion: September 2014
Project Manager: Dave Gore
The project was to completely replace the plant room and heating system throughout the school during the summer shutdown. It was a big job with a very tight programme.
The existing boiler plant and heating within the college were fully decommissioned, stripped out and removed from site. New gas-fired, high efficiency condensing boiler plant was installed to provide the heating requirements within the main building, DT Block and dining room areas. This was located within the existing boiler room that had been stripped out before refitting began. The boilers used were Potterton Sirius floor-standing models with stainless steel exchangers.
Within the plant room, a wall-mounted pressurisation unit with a floor-standing expansion vessel was installed to maintain the system design pressure. A new flue liner was also used within the existing chimney stack, with a new flue header from the boilers. The condensate drain from the flue discharges to the outside drain point using plastic condensate pipework. Completion of this phase of work also involved some associated builders work, making good with the need for access scaffold.
The existing incoming gas main was extended to serve the new boiler plant, complete with a gas isolation valve and gas solenoid valve. As an extra safety measure, an emergency gas shut off button was added close to the boiler room exit door to shut off the gas supply in an emergency. This was backed up by thermal link heat detectors above each boiler, which if activated will automatically shut off the gas supply. All pipework within the boiler room, ceiling voids and roof space areas was insulated using phenolic foam, foil finish insulation.
The new boiler plant is controlled by a new Building Management System (BMS), with the main control panel being located within the boiler room. This provides full optimised/compensated temperature control of the heating system and prevents tampering.
Within the main building, we created a new fully compensated heating circuit serving a range of steel panel radiators, radiant panels, fan convectors and over door heaters. All radiators were specified to use tamperproof thermostatic radiator valves that give local temperature control within each room. They are set and locked at setting 3 to prevent tampering by pupils. Radiant panels were installed in the laboratory areas to supplement the radiators, as there is insufficient wall space to provide the required heating levels with radiators. These are controlled by a wall-mounted temperature controller for local temperature control.
The dining hall area is served from a constant temperature circuit which also feeds the main hall, foyer and adjacent toilet areas. The dining hall and the main hall are heated by means of fan convectors to provide a rapid heat up to these areas when required. This circuit can be operated independently of the main school circuit.
The main pipework was designed to run at high-level within the ground floor corridor areas, with branches to serve the ground and first-floor classrooms. This again prevents the risk of tampering and vandalism.
The old hot water cylinder serving the canteen kitchen area was removed and replaced with two new Andrews Fastflo gas-fired, wall-mounted, high-efficiency water heaters located within the existing cylinder room. The existing pipework was removed to allow for the re-connection of the new pipework.
Within the DT block, The existing fan convectors and radiators were removed and replaced with new.
The Biddle fan convectors specified, use in-built return air thermostats and low-temperature cut outs. The existing boiler plant was removed and replaced with a wall-mounted high efficiency condensing boiler to provide a total output of 140Kw. A new room sealed flue was installed, terminating on the existing elevation of the boiler room. A wall-mounted pressurisation unit with floor standing expansion vessel was installed to maintain the system design pressure.
Being separate to the main plant room, the integral boiler controls and timeclock enable the system to operate at its maximum efficiency at all times, depending on the ambient conditions. Overall, we fitted over 100 new radiators and prior to handover, all pipework was flushed, chemically cleaned and water treatment added in accordance with BSRIA standards, with a dosing pot installed for future chemical treatment works.
The project ran smoothly, but due to the scale of project and the very short timescale for delivery, meant some long hours on-site for the team.