chimney
Enable an agent to recognise a chimney, record its construction and service condition, and determine what evidence is needed before connection, use, inspection, repair or retirement.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an agent to recognise a chimney, record its construction and service condition, and determine what evidence is needed before connection, use, inspection, repair or retirement.
A chimney is a structure containing one or more flues that convey combustion gases from a fireplace, furnace, boiler or other combustion source to the outdoor atmosphere, usually above roof level.
It can be Map connected combustion equipment to each inlet, flue and terminal.; Compare proposed service with documented chimney construction and ratings.; Plan inspection and cleaning around access points, passage geometry and known deposits.; Interpret draft, temperature and leakage observations within their test conditions.; Identify defects requiring competent assessment and record resulting use restrictions.; Track repairs, relining or changes of appliance through renewed compatibility assessment..
Distinguishing features
Its intended service includes conveying combustion exhaust to an outdoor discharge; a ventilation-only shaft does not meet this scope.
The chimney is the constructed assembly containing or forming the exhaust passage; a flue is an individual passage within that assembly.
An appliance connector links combustion equipment to the chimney; it does not by itself identify the complete chimney assembly.
A roof projection must be traced to its passage and intended service before it is identified as a chimney; appearance alone is insufficient.
A freestanding industrial exhaust stack falls within scope when its service meets the combustion-exhaust boundary, despite differing from a domestic masonry chimney.
Scope
+ Chimney construction, supporting structure and contained flue arrangement
+ Exhaust path from chimney inlet to outdoor terminal
+ Interfaces with combustion equipment, building fabric and nearby openings
+ Draft, exhaust containment and compatibility with intended service
+ Inspection access, deposits, deterioration, repair and operating restrictions
- Combustion appliance design, fuel preparation and burner control
- Whole-building ventilation and heating-system design
- Upstream industrial processes and separate exhaust-treatment equipment
- Standalone flue liners and appliance connectors considered as component kinds
- Natural geological chimneys and ventilation-only shafts
Characteristics
- Construction system
- Masonry; factory-built metal; cast concrete; composite; other documented construction Determines which component details, inspection methods and repair evidence are relevant.
- Flue arrangement
- Number of flues, passage shapes, separation and inlet allocation Prevents separate exhaust paths and their connected equipment from being treated as one passage.
- Effective rise and passage dimensions
- Vertical inlet-to-terminal rise in m; passage dimensions in mm; cross-sectional area in m², each tied to a location Provides geometric evidence for assessing exhaust transport and equipment compatibility.
- Connected combustion equipment
- Equipment references mapped to chimney inlets and flues, including fuel and operating combinations Connects chimney requirements to the actual exhaust sources.
- Declared service envelope
- Documented fuel, temperature, pressure, condensate and fire-exposure classifications where applicable Supports comparison between intended duty and construction or product documentation.
- Operating pressure difference
- Pa, with measurement point, reference pressure, sign convention and operating conditions Allows draft or pressure behaviour to be interpreted without treating an isolated reading as universal.
- Exhaust temperature
- °C, with location, equipment load and measurement time Supports assessment against the documented service envelope.
- Clearance and terminal geometry
- mm or m to identified combustible materials, roof surfaces, openings and adjacent structures Makes installation constraints assessable against the applicable requirements.
- Passage and containment condition
- Recorded obstruction, deposits, cracking, joint defects, corrosion or leakage; inspected extent and unknown areas Separates observed condition from assumptions about inaccessible sections.
- Service disposition
- Unassessed; accepted for documented service; restricted; isolated; decommissioned Records what operation is supported by evidence and who established any restrictions.
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 19 findings · 34 questions.
Chimney identity and boundaries Establishes which physical assembly is the chimney and which exhaust passages and connections it owns.
Chimney, flue, connector and roof projection are easily conflated, producing incorrect boundaries and connection records.
Assembly identification
Identifies the constructed chimney and its intended exhaust service.
Chimney sense and extent
Record evidence that the assembly serves combustion exhaust and identify its physical limits.
- What evidence identifies this assembly as a combustion-exhaust chimney rather than a ventilation shaft or decorative projection? definition
- Where does the chimney begin relative to appliance connectors, and which terminal and supporting elements belong to it? boundary
Flues and connections
Separates the chimney assembly into identifiable exhaust passages and equipment interfaces.
Exhaust path allocation
Map each inlet to its flue, connected equipment and discharge point, retaining uncertainty where paths cannot be traced.
- How many separate flues exist, and which inlets and terminals belong to each? boundary
- Which drawings, inspections or installation records establish the current equipment-to-flue connections? provenance
Construction and installation Records the chimney's passage geometry, materials, support and interfaces with its surroundings.
The exhaust path and surrounding construction jointly determine which installation and repair assessments are needed.
Passage and lining
Describes the flue route and the materials forming its exhaust-contact surfaces.
Flue geometry and materials
Record rise, section changes, offsets, lining materials and joints for each flue.
- What are the inlet-to-terminal rise, passage dimensions and locations of offsets or section changes? measurement
- What evidence establishes the lining material, joint construction and continuity through inaccessible sections? provenance
Support and building interface
Captures structural support, penetrations, clearances and outdoor terminal placement.
Installation interface evidence
Identify supports and interfaces whose condition or geometry affects installation acceptability.
- How is the chimney supported and restrained, and where does it pass through floors, walls or roofs? boundary
- What measured clearances and terminal distances apply to identified combustible materials, openings and adjacent structures? measurement
- Which installation records or assessments establish the requirements for these interfaces? provenance
Exhaust service and performance Relates intended combustion service to the chimney's documented capabilities and observed exhaust behaviour.
A chimney's suitability depends on its connected equipment and operating conditions, not merely its presence or dimensions.
Service compatibility
Connects fuel, equipment duty and exhaust characteristics to construction or product evidence.
Documented service envelope
Record supported service conditions and identify proposed duties that lack compatibility evidence.
- Which fuels, equipment combinations and exhaust conditions are proposed for each flue? definition
- Which manufacturer documents, design records or competent assessments establish compatibility with those conditions? provenance
Draft and discharge
Records how exhaust moves through and leaves the chimney under specified conditions.
Operating behaviour evidence
Associate pressure, temperature and discharge observations with equipment load and environmental conditions.
- Is exhaust movement driven by natural draft, mechanical assistance or a combination, and where are the relevant pressure boundaries? definition
- What pressure and temperature measurements exist, with locations, reference conditions and equipment operating states? measurement
- Under which startup, simultaneous-use, wind or building-pressure conditions has spillage or reverse flow been assessed? provenance
Condition and hazard evidence Records chimney-specific deterioration, passage restrictions and evidence relevant to continued service.
External appearance cannot establish internal passage condition, exhaust containment or damage after abnormal exposure.
Deposits and obstructions
Describes material or objects that restrict the exhaust path or require cleaning assessment.
Internal passage condition
Record deposit type and extent, foreign obstructions and the limits of internal observation.
- What soot, creosote, debris, nesting material or other obstruction was observed, and where? measurement
- Which portions of the flue were inspected, by what method, and which remain unobserved? provenance
Containment and structural damage
Captures defects in exhaust boundaries, supports and weather-exposed construction.
Damage and leakage assessment
Locate cracks, failed joints, corrosion, displacement and water ingress, including evidence following suspected chimney fire.
- Which defects affect the liner, joints, outer structure, supports, flashing or terminal, and what is their recorded extent? measurement
- What inspection or test evidence addresses leakage and damage following any known abnormal event? provenance
- What use restrictions or further assessments follow from the documented defects? action
Inspection and service decisions Connects access, maintenance history and governing evidence to actions on the chimney.
Cleaning, relining and equipment changes require chimney-specific methods and a documented basis for returning to service.
Access and maintenance
Identifies practical access to the flues and records work performed on them.
Inspectable and cleanable route
Map cleanouts and inspection openings to the flue sections they serve and identify access limitations.
- Which openings and access routes permit inspection, deposit removal and debris collection for each flue? boundary
- Which cleaning or inspection methods are supported for this lining and geometry, and what isolation or access arrangements are required? action
- When was each flue last inspected or cleaned, and what report records the work and residual limitations? provenance
Acceptance and change control
Records the basis for service acceptance and reassessment after changes.
Service disposition basis
Tie operating status to applicable requirements, assessment evidence and unresolved conditions.
- Which jurisdiction, standard editions, issuing bodies and product instructions govern this chimney and its intended service? provenance
- What evidence and responsible assessment support the current service disposition? provenance
- What reassessment is required after relining, fuel or appliance changes, structural repair or decommissioning? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- This covers the built combustion-exhaust structure, not geological chimneys or other figurative and technical senses.
- Standards are recalled by designation; current editions, jurisdictional adoption and applicability require verification.
- The diameter range is illustrative for domestic wood-stove flues only; actual sizing depends on the appliance, fuel, chimney height and system design.
- Which of these check these first hold for the sense of chimney this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Masonry chimney
- Factory-built metal chimney
- Industrial chimney
- Single-flue chimney
- Multi-flue chimney
- Which of these kinds and varieties hold for the sense of chimney this model covers, and on what evidence? provenance
Identifiers and schemes
Recalled without web access and unsourced; every item is a lead to verify.
- European chimney performance designation - Classes for temperature, pressure, condensate resistance, corrosion resistance, soot-fire resistance and clearance to combustible materials - A performance classification under applicable European chimney standards, not a unique identifier for an individual chimney.
- Which of these identifiers and schemes hold for the sense of chimney this model covers, and on what evidence? provenance
Standards and regulation
Recalled without web access and unsourced; every item is a lead to verify.
- EN 1443, Chimneys - General requirements, issued by the European Committee for Standardization (CEN).
- EN 1856-1, Chimneys - Requirements for metal chimneys - Part 1: System chimney products, issued by CEN.
- NFPA 211, Standard for Chimneys, Fireplaces, Vents, and Solid Fuel-Burning Appliances, issued by the National Fire Protection Association.
- UL 103, Factory-Built Chimneys for Residential Type and Building Heating Appliances, issued by UL Standards & Engagement.
- Which of these standards and regulation hold for the sense of chimney this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Discharging smoke and combustion gases from domestic fireplaces and stoves.
- Exhausting combustion products from heating boilers and furnaces.
- Serving industrial furnaces, kilns and combustion plants.
- Supporting natural draft through the buoyancy of hot gases within the flue.
- Providing a heat-resistant route for combustion gases through or alongside a building.
- Which of these real-world use hold for the sense of chimney this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Internal diameter of a circular flue serving a domestic wood-burning stove - 150-200 - mm
- Which of these typical measurements hold for the sense of chimney this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Obstruction, inadequate draft or adverse pressure conditions can spill combustion gases indoors, creating a carbon monoxide hazard.
- Accumulated combustible deposits, particularly creosote from wood burning, can ignite in a chimney fire.
- Cracked masonry, failed joints or damaged liners can leak hot gases and expose nearby combustible materials to heat.
- Condensate and corrosive combustion products can degrade liners, mortar and metal components.
- Wind, weathering, foundation movement or inadequate structural support can cause instability and falling debris.
- Which of these failure modes and hazards hold for the sense of chimney this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- European chimney products commonly use performance classifications under EN standards; North American practice commonly refers to product listings and installation codes.
- Permitted terminal positions, chimney heights and clearances depend on local building rules, appliance type and surrounding structures.
- The terms chimney, stack, smokestack and vent overlap differently across regions and domestic or industrial practice.
- Which of these regional variation hold for the sense of chimney this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- flue - A flue is the passage carrying combustion gases; a chimney is the structure containing one or more such passages.
- flue liner - A liner forms the internal protective boundary of a flue and is a component of the chimney.
- stovepipe - A stovepipe usually connects a stove to a chimney; it is not necessarily suitable for the building penetrations or exposure handled by the chimney.
- fireplace - A fireplace contains the fire; the chimney carries its combustion products away.
- ventilation shaft - A ventilation shaft moves building air and is not necessarily designed to withstand or discharge combustion products.
- smokestack - Smokestack commonly denotes an industrial chimney; it is an overlapping term rather than a universally separate physical kind.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of chimney this model covers, and on what evidence? provenance
What the second pass must settle
- Does the registry intend chimney to include industrial combustion stacks, or does an existing registered model own part of that scope?
- Does an existing world model already cover this concept and therefore provide the authoritative publication?
- Which primary sources establish the relevant terminology and distinctions among chimney, flue, connector and exhaust vent across construction systems?
- Which jurisdiction-specific standards, classifications and assessment procedures apply to each chimney subtype and intended service?
- Which measurements and inspection findings are sufficient for a competent service decision, particularly where flue sections are inaccessible or historical construction records are absent?