BS EN 15287-2-2008 pdf download.Chimneys Design, installation and commissioning of chimneys
Part 2: Chimneys for roomsealed appliances.
4.3.4 Chimney system sizing and characteristics for roomsealed applications
The flue duct, the connecting flue pipe, the air supply duct and terminal shall be charactensed for size, pressure class and thermal parameters in accordance with the thermal and fluid dynamic calculation methods based on EN 13384-1 and EN 13384-2 or as specified by the heating appliance manufacturer or chimney manufacturer.
Where appropriate, the maximum allowable pressure difference between combustion air inlet and flue gas outlet of the heating appliance as specified by the manufacturer should be taken into account in the calculation.
4.3.5 Chimney system route
The chimney system route should be determined by the positions of the heating appliances flue outlet(s), air supply intake(s) and the point of chimney termination.
The chimney system route should be the shortest, most practicable direct route between the appliance outlet and the chimney outlet and should be as straight and as near to vertical as practicable, except for horizontal types. e.g. type C1 and C5. The non-balanced flue chimney outlet should be as near as practicable to the highest part of the building (e.g. ridge) to ensure adequate draught and dispersal of flue gas.
The chimney system route selected should enable the chimney manufacturer’s standard components to be used in carrying out the installation.
For a chimney operating under wet conditions with multiple inlets, a means shall be provided for preventing condensate from re-entering an individual heating appliance. This may be achieved by ensuring that the entering position of the lowest connecting flue pipe is above the level of condensate collecting at the base of the chimney or in the collector.
Chimneys and connecting flue pipes route should be designed in such a way that the comfort of rooms is not adversely affected.
NOTE Attention should be given to heat emitted from the chimney and connecting flue pipe in applications where whole year operation is likely to affect comfort. A thermal resistance of 0,22 m2Ke’W is recommended for temperature class T300 and above.
4.3.6 Connecting flue pipe and connection air supply pipe route
The connecting flue pipe arid connecting air supply pipe shall not pass through a ceiling or into another fire compartment unless allowed in national regulations.
A connecting flue pipe designated suitable for wet operating conditions, shall be inclined to allow condensate to be drained.
Where an installation design requires the use of fire stops, including those that act as combined fire stops and spacers or as ceiling/floor supports, in order to meet the cntena for resistance to fire (external to external), in the absence of specific European Standards, these shall be as tested according to national regulations for preventing the spread of fire.
4.3.8 Distance to combustible material (Resistance to fire internal to external)
4.3.8.1 System chimneys
The minimum distance to combustible materials for a system chimney declared by the manufacturer in accordance with the relevant product standards shall be used.
The minimum distance to combustible material for a chimney system supplied as an integral part of the heating appliance shall be in accordance with the heating appliance manufacturer’s Instruction.
A system chimney which passes through a combustible wall shall be sleeved and/or shielded to maintain the appropriate distance to combustible material or in the case of cavity wall construction to contain any infill. Any sleeve or shield opening to the outside of the building shall be weatherproofed.
The distance to combustible materials may be reduced where the expanse of the combustible material is small, e.g. skirting boards, rafters, joists, etc. In some circumstances the combustible material may touch. This shall only be allowed by individual member states regulation.
4.3.8.2 Custom built, relined and converted chimneys
The minimum distance to combustible materials for a custom built, relined and converted chimney shall either be as declared by the manufacturer, or be determined in accordance with the calculation of Annex A.
NOTE 1 Equation A. 1 covers the case of non-ventilated spaces between the chimney system and combustible material and gives the maximum allowed flue gas temperature for a given distance.
NOTE 2 EquatIon A.2 covers the case of ventilated spaces between the chimney system and combustible material and gives the maximum allowed flue gas temperature for a gap of a minimum 4 cm,
A custom built chimney which passes through a combustible construction shall be sleeved and/or shielded to maintain the appropriate distance to combustible material or in the case of cavity wall construction to contain any infill. Any sleeve or shield opening to outside shall be weatherproofed
The distance to combustible matenals may be reduced where the expanse of the combustible material is small, e.g. skirting boards, rafters, joists, etc. In some circumstances the combustible material may touch. This shall only be allowed by individual member states regulation.
A concentric chimney system up to a temperature class T160 and where sootfire cannot occur requires no distance to combustibles and therefore no sleeve.BS EN 15287-2-2008 pdf download.