1 Scope
This code of practice gives recommendations for the design and construction of fluelinings and flue structures serving appliances (boilers and air heaters) of 45 kW output and above,
burning solid, liquid or gaseous fuels.
The recommendations contained in this code may be used for the design of a flue serving an incinerator, which should be provided with its own individual flue.
Prior approval of the height of the chimney by the local authority is required by Section 6 of the Clean Air Act 1968 where the
appliance(s) served by the chimney burn(s) (a) pulverized fuel or (b) 45 kg or more of solid fuel per hour or (c) liquid
or gaseous fuel at a rate of 366 kW or more if:
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(1) a new chimney is erected to serve a new or existing installation; or
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(2) an installation (e.g. of boilers, incinerators) served by an existing chimney is enlarged, e.g. its combustion capacity is increased, or an additional appliance
is added to the system; or
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(3) an appliance served by an existing chimney is removed and replaced by one having a larger combustion capacity.
The official publication Chimney heights. Second edition of the 1956 Clean Air Act Memorandum,* subsequently referred to in this code of practice as the 'Chimney Height Memorandum', gives guidance for the calculation of heights likely to be suitable
in most instances for solid or liquid fuel appliances.
Useful information to facilitate calculation of possible chimney heights for gaseous fuel is contained in the Cl8S Guide, Volume 8, Section 813 (1970)†.
This code applies to:
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(a)
linings that are built within a space enclosed by a building;
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(b)
linings that are built as an integral part of the building.
This code does not, in general, apply to linings within a freestanding or independent chimney, but many of the conditions and criteria are applicable.
The design of fluelinings and flue structures in buildings is subject to increasing knowledge and experience, and should
be undertaken only by those competent to evaluate the many aspects of satisfactory
construction and performance. This code provides the building services engineer and
the structural engineer with design criteria, suggested procedures and methods of
design, recommendations for construction, and basic guidance data for the selection
of lining materials.
The code also seeks to augment the skills of experienced designers who will need to
interpret the information and examples with appropriate professional expertise, giving
due consideration to all the relevant issues involved.
The examples and calculations in this code are given as one form of use of the data
provided. They do not preclude other methods of computing satisfactory designs.
Where appropriate, detailed information has been put in appendices.