Project Description

The Project:

The scope for this project was to design, supply & install 3 x 400mm internal diameter stainless steel twin wall flues to serve each of the Hoval CompactGas boilers as well as a high pressure stainless steel twin wall flue to serve the CHP unit. This plantroom was to serve the entire complex for hot water and heating needs as required and need to keep each boiler individually operating to match demand and reduce down time impact for maintenance etc.

The prestigious new build complex is located on Blackfriars road, 5 minutes from Waterloo station in the heart of central London.


Key factors for the design included:

  • The supply & installation of 3 x new 316 stainless steel twin wall insulated class 1 rigid flues to serve 3 x Hoval CompactGas 1400 Boilers (1400kW each) which measured an impressive 2.6m long x 1.6m high x 1.48m wide with a 400mm diameter spigot.
  • The supply & installation of a new high pressure flue to serve a new CHP unit connecting into a 2.3m high attenuator unit via a flanged adaptor with a twin wall insulated high pressure 316 stainless steel flue capable of withstanding high positive pressure applications.

Product Specification:

The following product specification was used throughout the project:

  • Hoval Compactgas Boiler Flues – Poujoulat 400mm ID / 464mm OD Twin Wall Insulated 316 Stainless Steel Flue.
  • CHP Unit Flue – Poujoulat 150mm ID / 200mm OD Twin Wall Insulated 316 Stainless Steel High Pressure Flue.


The design, supply & installation of all the systems were completed by Chimflue over a period of 4 weeks. This included offloading and distributing 88 pallets of flue materials and accessories into the basement plant room and then loading out each of the 28 storeys with the required materials. All uni-channel and studding was cut out of hours to reduce the time on site. Our engineers worked in the heat of the operational plantroom to install the flue systems serving each appliance via a specially built scaffold platform in place by the main contractor. Once the plantroom sections were complete our teams constructed the flues up through the dedicated riser walking the internal staircase from basement two to 3m above roof level some 28 storeys above ground level. Each riser was a whopping 112m high with staggered support bracketry as space between the widths of each flue was limited.

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