IS A MULTI-PURPOSE CONCENTRIC FLUE SYSTEM in a lightweight design, suitable to operate with condensing gas appliances in positive pressure with temperatures up to 200 °C. The system should be suitable for both: the installation inside a house as well as outside on the facade, which would give this system an advantage compared to competitive products. For chimneys suitable for external application, it is essential to prevent rain penetration to get into the cavity between the inner liner and the outer case, what was achieved by reversing outer pipe‘s socket compared to the inner liner, meaning in opposite direction to flue gas flow. The next request in the development process of the CFS was to be compatible with ICS 25 and Prima Plus systems, which may occur very well in some specific cases of installation.
The CFS system is available in three standard diameters: 80/130, 100/150 and 130/200 mm.
The inner liner is made of EN 1.4404 (AISI 316L) steel grade, while the outer case is made of EN 1.4301 (AISI 304) steel grade, both in 0,4 mm thickness. The CFS system is currently available in bright annealed outer case finish or painted white.
// multi purpose concentric system in lightweight design
// suitable for internal and external application
// for operation in positive pressure
// high quality engineered joints secured by locking bands
// wide range of installer friendly accessories
// can be combined with Prima Plus and ICS system
// flue gas extraction and air supply of room-sealed appliances
// condensing appliances
// in residential or commercial use
The joints of the CFS system are made by means of a simple push fit jointing method. This is achieved by the engineered spigot and socket system having a pronounced lead-in-edge to ease the assembly. All CFS elements are designed to allow for thermal expansion of the liner within each joint, so there is no requirement for any additional expansion joints.
The Pressure tightness is achieved by a silicone lip seal gasket fitted to the inner liner, which can be exchanged with gasket made of Viton, when using the chimney system connected to an appliance burning oil. When installing CFS components, gaskets should be fitted dry and lubricant applied to the internal of the female liner socket. The elements are secured by locking bands, which are supplied together with every item.
When installing the CFS as the connecting flue pipe in a horizontal run a required 3° slope (5 cm/m) towards the appliance should be taken into account to ensure condensate flow. This is also important to consider when making a transition from a vertical section to a horizontal run by using the appropriate 87° bend or 87° tee. In longer horizontal runs it is advised to install additional supports to support the flue in order to maintain the required slope.
The vertical section of the chimney can be supported from floor level by using a base support plate, or floor support; from first floor level by using a support plate fixed to the floor/ceiling joints, or as an outside installation from the wall by using wall support top plates together with side plates or cantilever brackets. In longer vertical sections wall brackets should be used on every 4 m to provide additional lateral support.
The system is designed to simultaneously supply gas appliances with combustion air and extract flue gases into the atmosphere, so special attention was drawn to design the terminal‘s aerodynamic properties in order to achieve the required performance and safe operation of the connected appliance.