CFS-FA Positive pressure

Communal Flue System - Fan-Assisted positive pressure

CFS-FA is Cox Geelens complete flue system which combines a communal air supply and a communal flue outlet for use with fan assisted boilers that are fitted with non-return valves. The non-return valve on each boiler connection is essential to prevent recirculation of exhaust gases to non operational appliances.
Cox Geelen CFS Overpressure
Cox Geelen CFS Overpressure

  • The outer aluminium pipe has a fully welded longitudinal seam and is roll grooved for maximum rigidity. The CoxSafe seal applied to the male o/d circumference ensures an airtight male/female joint at installation assembly.
  • The aluminium inner pipe has a 1.5 mm wall thickness, has a longitudinal TIG-welded seam with its female end fitted with the latest Fix-Safe seal (FS) for a gas-tight and condensate-tight push fit joint.
  • The elasticity of the Fix-Safe seal combined with its unique design ensures optimum sealing performance.
  • Each CFS-FA system is supplied as a complete kit of parts to build the complete assembly installation comprising: a roof terminal with storm collar, a tile with lead flashing or flat flashing, concentric T-piece with appropriate number of connections per storey, concentric sections, a condensate collector base unit, floor brackets and floor supports.
  • As an aid to section assembly we recommend applying soapy film to the joint seal surfaces prior to push fit connection (obtainable from Cox Geelen).
Concentric diameter data is specific to the number of appliances connected and is available upon request.

  • The CFS-FA (overpressure) system is CE-marked according to the European standard EN 1856-1.

Somerset Place, Bath, CFS project

Somerset Place Bath listed building CFS project

At the end of last year (2014) Cox Geelen was approached by the developer regarding a CFS project at Somerset Place, Bath.
Cox Geelen got involved due to their listed building status.

Somerset Place is a Victorian Terrace in the heart of Bath. The properties in Somerset Place are subjected to very tight restrictions on what can be done to their appearance on the outside, as they are called 'Listed Buildings' in the UK. The building being refurbished was originally a wealthy persons house.The property was purchased by the developer and was undergoing a major refurbishment, being converted into 'High End' apartments and the boilers servicing these needed to be flued vertical to meet the planning requirements.

This unique CFS project allowed Cox Geelen to show something different to the traditional new build projects. Installation of separate boilers in each apartment but not flued individually as no terminations were allowed on an outside wall. 
Various Aladin calculations were carried out to give boiler chimney options. A decision was made on the best chimney option - Cox Geelen's CFS positive pressure - and boiler configuration. 

With the Cox Geelen CFS system the local planning authority had a solution to the problem by being able to connect all the boilers to a single chimney which then exits the roof. The building contractor could carry out the installation of the CFS, the plumbing and boiler installation work.

Non-return valve

NEW: Cox Geelen Non-return valve
Boilers planned for use with the CFS-FA overpressure flue system should always be connected via a non-return valve. If these boilers do not have factory fitted integral non-return valves on the flue exhaust then the solution is simple: Install a Cox Geelen non-return valve in the flue gas pipe run at the exhaust of the boiler. The prime function of the non-return valve is to prevent recirculation of flue gases from active appliances on the CFS from flowing back into any
non active appliance. Precondition for this solution is that the boiler must be suitable for overpressure.

The new innovative valve is designed by our own R & D department.
Specifications Non-Return Valve
non-return valve
non-return valve