Biomass Flue System
Grant wood pellet boilers have their own unique high temperature flue system. This 125mm (5”) vertical conventional stainless steel, twin wall insulated chimney system specifically designed for use with Grant pellet boilers. It has been fabricated to cope with continuous operating temperatures up to 200°C although the typical flue gas temperature produced by the Spira is much lower than this. The system is designed so that the stainless steel outer case is load bearing and stainless steel inner liner is free to expand independently to accommodate temperature change.
Available with a range of extension pieces and bends in a black or white finish, the system can easily be assembled to suit a wide variety of installations.
Sections are joined together by placing the female collar of one section over the corresponding male collar of the preceding section then locking by rotating the upper section clockwise. It is vital that all flue gas carrying components are installed with the external collar pointing upwards. An arrow on the label indicates the flue gas direction.
The inner of each section is enlarged at the male end so that the female end of the other section or fitting enters into it and overlaps. This allows any condensation to run back to the boiler without escaping from joints.
The flue should remain as straight as possible through its vertical run to assist flow. Should it be necessary to angle the run, an offset no greater than 45° to the vertical, with a run between the bends not exceeding 20% of the overall height of the chimney should be maintained. A vertical rise of 600mm should be allowed immediately above the appliance before any offsets. Reference for both guidelines can be found in the Building Regulations Document J and relevant British Standards on installations.
- Twist-lock bayonet jointing system. Secured by locking bands
- Advanced corrosion resistant design and construction
- The 25mm high efficiency Superwool blanket maintains flue gas temperature, maximising efficiency, improving flue draught on start up and minimising condensation.
- Low external case temperature.
- Inner liner held by the male locking collar but free to expand and contract with temperature by up to 18mm through the female collar.
- The inner liner has an inward bead at the female end which acts as a capillary break preventing moisture beingdrawn through the joint.