Send CofE Junior School, Woking — replacement of the school’s main plant room within a three-week programme, covering gas service alterations, new gas-fired condensing boilers, a designed flue system, new controls, and weatherproofing of the flat roof around the new flue.
A three-week window
Replacing the heating plant in a school is governed as much by the calendar as by the engineering. The heating has to be out of service while the old plant is removed and the new plant is installed, and it has to be back in service, cleansed and commissioned before the building is occupied again. At Send CofE Junior School the whole replacement was programmed into three weeks.
That window shaped the sequence. Strip-out and disposal of the existing plant room equipment, alterations to the incoming gas service, installation of the new boilers and plant, cleansing, commissioning and the builders work around them all had to be planned as one continuous operation rather than as separate visits.
Designed as well as installed
ComGas was responsible for the design of two elements of this project as well as their installation: the flue system and the controls.
Moving to gas-fired condensing boilers changes what a flue has to do. Condensing plant operates at lower flue-gas temperatures and produces condensate, so a flue that served earlier non-condensing boilers is rarely suitable to be carried over. A new flue system was designed for the replacement boilers and installed as part of the same package.
The control strategy was designed alongside it. That matters on a plant room replacement, because it is the difference between new boilers commissioned as a complete system and new boilers left working against control equipment inherited from the plant they replaced.
Scope of works
- Strip-out and disposal of the existing plant room equipment
- Modifications to the existing gas service
- Installation of new gas-fired condensing boilers
- Design and installation of a new flue system
- Installation of new plant room equipment
- Design and installation of new controls
- Pre-commission cleansing
- Testing and commissioning
- Builders work in connection with the mechanical installation
- Making good and weatherproofing of the flat roof around the flue
- Provision of record documentation
Finishing the roof rather than leaving it
A new flue has to pass through the building envelope, and at Send that meant a penetration through a flat roof. Making good and weatherproofing around it was carried out by ComGas within the mechanical package rather than passed to a following trade.
For the school that means one contractor is accountable for the roof being weathertight, and there is no gap in the programme between the flue being installed and the roof being finished. The associated builders work in connection with the mechanical installation was handled the same way.
Handover
The system was cleansed before commissioning, then tested, commissioned and handed over with record documentation for the school to keep alongside its other building records.
Work of this kind sits within the commercial plant room installations ComGas carries out for schools and academy trusts, where the programme is normally fixed by the school calendar rather than by the works. Plant of this kind is also covered by our planned service and maintenance.
