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Comments on BS EN 15287 National Annex – Docherty Chimney Group

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Comments by Mick Waumsley

Technical Director, Docherty Chimney Group

On National Annex to

BS EN 15287-1:2007 +A1:2010 Incorporating corrigendum November 2008

Chimneys — Design, installation and commissioning of chimneys Part 1: Chimneys for non-roomsealed heating appliances


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IntroductionThe writer is a member of BSI Committee RHE28 and the HETAS technical Committee and had expected to be circulated with draft copies of the revised National Annex to BS EN 15287 but in the event this was not the case.

When the published document became available before I had seen the Draft it became apparent that changes had been made that, over the 35 Years of experience in the solid fuel Industry in design, research and development, field investigations and training, I felt where a retrograde step in safety and left the opportunity for compliant installations to be dangerous I felt the need to take action.

As a result of that action a number of other experienced members of the industry felt compelled to join in the debate and as such there is a combined meeting of RHE 28 and the HETAS technical committee.

The Chairman of both these committees has seen fit to limit the debate to only two main issues but I am of the opinion that there are far more issues than this that need consideration and debate.

Now I have purchased a complete copy of the new issue of the standard and read the document and have many issues with it, some safety related and some purely based on getting the editing and explanations correct and less open to interpretation.

I have produced this document to enable others in the industry to see my comments and consider if any are worth of their support and to ensure that if any changes are to be made to the standard then all the required changes are made in one go rather than having to wait to the next issue before errors are corrected.

I hope these comments are taken as constructive and in support of my wish to ensure the safety of the UKs solid fuel users at a time when the reputation of the industry is improving and its future needs to be secured. (As I am sure is the case with all involved)

From this point on I have taken the National annex in order and made comment, some are trivial but should perhaps be corrected if any changes are to be made and others are critical to the safe interpretation of the standards intensions.

Conclusion

It is my conclusion that the standard as written is a step back in terms of solid fuel appliance user safety.

There are many changes that research has shown to be far from universally safe and are potentially dangerous without major clarification or change.

There has been no testing to confirm these changes are safe and no results that show the methods proposed are safer, or at least as safe, as those practices currently being employed in the Uk.

I have proposals for testing from CRE and the provision of equipment for use in these tests from companies within the industry that are of similar opinions to my own.

The standard should be withdrawn until a consensus from within the industry is reached that is based on testing and results and that can be verified as safe in a court of law if an expert witness is called upon to pass opinion.


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1. NA 1 Para 4

This annex is confined to chimneys and flue pipes serving appliances with a maximum heat output of 50 kW and the average temperature of the flue gases leaving the appliance has been assumed not to exceed 400 °C under normal operating conditions. The chimneys and flue pipes will normally withstand much higher temperatures that can arise during overrun conditions and chimney fires for short periods..

The Introduction makes the following statement; there are already a number of manufacturers stating their appliances have flue gas temperatures of greater than 400⁰C at nominal output (Stovax Riva as an example)

Should the standard make comment about the need to ensure the appliance manufacturer’s figures are obtained and the temperature rating of the flue be chosen to suit? In addition are there any issues that may be relevant if this is the case, if so what and what precautions should be taken.

A majority of solid fuel appliances work on lower than 400⁰C and does this have a bearing on the flue arrangement, should there be a minimum around which these arrangements can be used without reference to BS EN 13384

In addition we should use wording as standardised in the EN and as such it should say “connecting flue pipe” not just flue pipe.

2. NA.2.2

Chimney breast

Projection beyond the thickness of a wall containing the fireplace and flue(s)

I would suggest the additional wording “whether internal or external” added to the end of this definition.

3. NA.2.5

Chimney terminal (chimney pot)

Fitting installed at the outlet of the chimney

Perhaps adding “excluding any cowl”.

I believe from previous standards that this is a flue terminal and that a chimney terminal is a slab or similar finishing or weathering that is placed on the structure to shed water.

4. NA.2.12

Flaunching

Weathering formed in mortar at the top of a chimney or base of a terminal

In most cases this also the term used for the angling up from the fireback in an open fire or the flue pipe into a gather over a register plate, are these relevant and if so should they be added here.

5. NA.2.13

Flue


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Passage for conveying the products of combustion to the outside atmosphere.

Should this say words such as “A Passage from the outlet of the combustion appliance to the chimney terminal for the conveying of the products of combustion. This includes the connecting flue pipe as well as any part of the flue contained in the chimney.

6. NA.2.14

Flue adaptor

Fitting between the appliance flue outlet and the inlet to a flue pipe or to the chimney flue

The word connecting should be in front of the words flue pipe.

7. NA.2.15

Flue block

Factory‐made single or multi wall chimney component with one or more flues

I believe these cannot be steel and so we should either add the word masonry or exclude steel from this.

8. NA.2.17

Connecting flue

Component or components connecting the heating appliance outlet and the chimney

I believe this is known as a connecting flue pipe.

9. NA.2.18

Fly ash

Fine particles of ash entrained in flue gases

Consider also “and which may be deposited in the flue system or expelled from the chimney terminal”

10. NA.2.22

Oversailing

Courses of stone or brickwork (masonry) arranged to project from the face of a wall or chimney stack largely for decorative effect

This is not a decorative effect it has two very distinct functions that greatly affect the performance and life expectancy of a masonry chimney stack. It is in fact a custom made chimney terminal (as opposed to flue terminal) in that it allows the chimney pot to be bedded in the chimney stack without causing a reduction in the flue size and it also has the effect of allowing soot contaminated rain (which will be acidic) to drip of down to the roof surface without running down the face of the chimney stack causing damage to the mortar joints. Without this a stack will need repointing approximately every 20 years as opposed to every 50 years.

11. In the section NA3 paragraph one the following sentence appears;


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NA.3 Exchange of information

Full details should be obtained whenever possible from the manufacturers regarding any special requirements of appliances affecting flue size, insulation and chimney height.

Since we now have the grading system to BS EN 1443 I would suggest this is also added in, such as

“Full details should be obtained whenever possible from the manufacturers regarding any special requirements of appliances affecting the flue characteristics and grading to BS EN 1443, flue size, insulation and chimney height and the minimum and maximum draw required in Pascals.

12. NA.4.1 Materials, appliances and components

With the imminent change from CPD to CPR should there not be a sub‐section or paragraph discussing CE marking in this section.

13. NA.4.2.1 General b) masonry chimneys should be lined except when constructed in accordance with NA.5.6;

I feel this could be worded similar to the following to bring more into line with ADJ

“b) masonry chimneys should be constructed to include a suitable non‐metallic lining except when constructed in accordance with NA.5.6;”

c) the cross‐sectional area of the flue and the vertical height should be considered in relation to the type of appliance it has to serve (see NA.4.2.3);

Perhaps this should include the output and fuel type as well.

e) rough internal surfaces, too flat gradients, abrupt changes of direction and sudden enlargements or contractions of the flue should be avoided;

I agree fully and in my opinion this should include the connecting flue pipe

f) the number of bends, where these are unavoidable, should be kept to a minimum and in no case should a bend be used with an angle of more than 45° (but see NA.4.5);

I agree fully and in my opinion this should include the connecting flue pipe

h) sometimes a chimney and especially a chimney terminal, is particularly exposed to the weather and precautions are necessary, such as the proper selection of masonry units (particularly bricks and mortar) and protective detailing, as protection against the weather (see NA.5.2);

Perhaps this could include something about excessive cooling.

i) chimneys on internal walls are to be preferred in order to minimize loss of heat from the flue and also to retain useful heat within the dwelling;

If a chimney runs up the outside of a house Whether custom built or a chimney system then the ability of the chimney to avoid dew point should be confirmed using the calculations in BS EN 13384

14. NA.4.2.2 Relationship to heating appliance

Open fireplaces function primarily as air collecting hoods in which small amounts of combustion products are diluted with relatively large amounts of air.


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I believe these fireplaces function primarily as a hood for the collection of the products of combustion and as a consequence they do collect large quantities of air. If the word air is omitted between “as” and “collecting” this sentence is more accurate.

15. NA.4.2.3.1 Chimneys serving an appliance recess

For a chimney built with a fireplace recess in which an open fire, a room heater or stove may be fitted, a flue size of 200 mm diameter or rectangular/square flues having the same cross‐sectional area and a minimum dimension not less than 175 mm diameter.

I feel the use of the word Diameter at the end of this sentence is confusing. Although the dictionary also gives a definition of width for the word diameter its common use is for the straight line from one side of a circle to the other passing through the centre. I accept that the use of the word here is not strictly wrong it is open to interpretation as a 175mm round liner.

16. NA.4.2.3.1 Chimneys serving an appliance recess

Providing that a chimney is constructed in accordance with NA.4.2.1, the most important factors influencing the size and height of a flue for an open fire are the configuration and dimensions of the throat, lintel and entry to the chimney flue, and the air flow velocity into the fireplace opening. Recommendations for the construction and design of fireplace recesses and the installation of open fires are given in BS 8303.

It has long since been known that the main issue regarding the sizing of a flue for an open fire has been a combination of height and fireplace opening size. It has also been known that without taking the height into consideration the flue ratio of 15% will result in flues that are too large for the fireplace if the effective flue height is more than 5 meters. The Scotland Technical hand book section 3 provides a graph that takes the effective flue height into account when providing a flue area for an open fire. This has given less problems than the system in ADJ. This will reduce flue sizes for taller chimneys and hence reduce vent sizes, to compensate for the additional draw created by the height. This has reduced the incidence of condensation and damp soot deposits in open fire flues. Should we take the opportunity to introduce this here?

17. NA.4.2.3.3 Chimney height

For chimneys, a height of about 4,5 m (the height being measured above the top of the fireplace opening) is normally sufficient for flue draught. The recommendations for the height of the chimney outlet above the roof of a building are given in NA.4.7.

Many of these installations are going to be stoves and so I recommend adding in a statement in to the brackets such as “or from the flue outlet spigot of a top outlet appliance and the centreline of the flue outlet spigot of a rear outlet appliance”.

18. NA.4.2.3.4 Calculation methods

If sufficient information is available from the appliance and chimney manufacturer the flue size can be calculated using the calculation methods given in BS EN 13384‐1 and BS EN 13384‐3.

Although I do not agree with the use of long horizontal runs (over 150mm) or sharp bends from the vertical (more than 45⁰) I feel that this is the paragraph that should be altered so that if they are to be introduced into the UK we make sure they are as safe as possible and recommend the following

“If a system chimney is to be used to provide the flue then sufficient information is available from the appliance and chimney manufacturer to enable the flue sizes to be calculated using the calculation methods given in BS EN 13384‐1 and BS EN 13384‐3.


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If this is the case then the method of connecting the appliance to the chimney system described in NA 7.2 with bends greater than 45⁰ from the vertical and horizontal runs greater then 150mm can be followed if the calculation shows sufficient draw, flue gas temperature and flue gas velocity are achievable.”

I repeat I am very much against this but see it as a compromise and will prevent the assumption that this can still be used as a method of installing to an existing chimney that may not be sufficiently warm or air tight.

19. Figure NA.2 – Construction of fireplace recess with raft lintel

In all previous documentation this is called a universal fireplace recess and is not only for closed appliances. ADJ shows this method and then shows how the use of a pre‐cast concrete gather can make it suitable for a BS 1251 fireplace component set.

I believe this should be added in to this section and shown first as the preferred method. It is a fact that a majority of future appliances are going to be stoves and this recess will be more suitable for this. It still gives the option for an open fire later.

I can also say that in the field there is far less likelihood of liners being placed in a chimney upside down if this construction method is used.

20. NA.4.4 Condensation

Condensation may occur when the appliance is lit and the flue surfaces are relatively cold and Also where the temperature and volume of the flue gases are low, such as when a closed appliance is operating at a low burning rate.

We should be encouraging the designs of flues that minimize the formation of condensation and if so we should be warning against it and informing of the dangers of the damage it can do to steel chimney systems and liners.

On chimneys constructed prior to 1966 without flue liners burning wood on a closed appliance produced special problems of condensation due to the high concentrations of water vapour. The tar‐like materials in the flue gases passed out through the mortar joints and stained the brickwork externally (see National Annex NB (informative)).

This paragraph should be removed as it is not relevant here. This section is about the construction of new flues not the repair or suitability of old ones.

21. NA.4.5 Bends and changes of section

Flues should be vertical wherever possible. Flue systems should offer least resistance to the passage of flue gases by minimizing changes in direction or horizontal length. A way of meeting the requirement would be to build flues so that they are straight and vertical except for the connections to combustion appliances with rear outlets where the horizontal section should not exceed 450mm. Where bends are essential, they should be angled at no more than 45° to the vertical. (See NA.7 and Figure NA.7.b)).

I am against the use of such a long horizontal section. There are many of my contemporaries that come across this type of installation who would agree with me and I will be encouraging them to make this known to the chairman of RHE 28.

Provisions should be made to enable flues to be swept and inspected. A way of making reasonable provision would be to limit the number of changes of direction between the


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combustion appliance outlet and the chimney outlet to not more than four (each up to 45°), with not more than two of these being between an intended point of access for sweeping and either another point of access for sweeping or the chimney outlet. (90° factory‐made bends, elbows or Tee pieces in fluepipes may be treated as being equal to two 45° bends (see Figure NA.3).

If I have a 90 degree swept bend on the back of the appliance this is two bends and as such I must have access to this bend or an area just above it with a suitable access for a sweeps rod to be used, if there is any other bend in the flue then this does not include sweeping through the appliance as this will require the sweeping of all four bends from one access point. This will require a second sweeping access.

It should state, as it does in ADJ that there must be a debris collection space that can be accessed for cleaning and be located so that any fall of deposits from the chimney that cannot fall directly into the appliance will fall into this space.

The use of a 90⁰ factory made bend should not be acceptable with solid fuel. The use of a 90 degree elbow must be outlawed even if a calculation is carried out.

It is my opinion that this should read that the use of a 90 degree factory made tee may be treated a two 45 degree bends.

22. NA.4.6 Openings into flues and communicating flues

No opening should be made into any flue in a chimney except for:

a) inspection or cleaning, where the opening is fitted with a non‐combustible cover of double door construction; or

b) draught stabilizer, made from durable non‐combustible material, fitted in the same room as the appliance.

The description of the soot door should be along the lines of that in ADJ 1.51 and the description of a draught stabilizer may be better if it was along the lines of;

b) draught stabilizer, made from durable non‐combustible material and suitable for the rating of the flue it is fitted to, fitted in the same room as the appliance.

23. NA.4.7 Height and position of chimney outlets above roofs

NA.4.7.1 General

It will be seen from Figure NA.4 a) that

Figure NA4 does not have labels a, b or c and so needs to have these added

Figure NA.4 c) shows a flat‐roofed building

I would assume that c is the last of the three illustrations but the flat roof is at the top, these need checking and putting in the correct order, either on the illustration or in the written section. Note also that there is no area z shown on either of the pitched roof illustrations

Figure NA.4 c) shows a flat‐roofed building and illustrates that a suction zone is created on the roof. From this it will appear that a chimney through a flat roof will be immune from smoke/fume emission at the appliance.


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I am sure that this is correct when considering the wind but it suggests this is safe no matter what. I suggest wording along the lines of

“Figure NA.4 c) shows a flat‐roofed building and illustrates that a suction zone is created on the roof. From this it will appear that a chimney through a flat roof will be immune from smoke/fume emission at the appliance caused by the pressures caused by wind direction and force, this may not be the case if parapet walls or other structures on the roof are within an area that could cause disturbance to wind flow.”

24. Illustration NA5

I feel this illustration should have the reference number on all the pages it spans.

In the heading it states without chimney pot but in illustration a) it shows the first 150mm of a chimney pot being taken into account. This should be brought into line with ADJ to include this first 150mm and so the title needs changing.

I am pleased to see the illustration for flat roofs being brought back into this document however the legend should be corrected.

It states “NOTE 2 The chimney should terminate outside the shaded areas.”

In the illustration the shaded area is the structure of the building and note the exclusion zone, this should be corrected and either a different shading and a key or a shading and the structure to be blocked out.

25. A chimney with any part passing through the roof greater than 0,6 m from the ridge but no further than 2,3 m, should terminate at a minimum height level with the ridge. For flat roofs a chimney outlet should be not less than 1,0 m above the roof.

It has always been my impression that once more than 600 away from the ridge the chimney to the datum point should be at least 1.0m high. This is an interpretation and I have seen the one used here before, which should we consider. I make my interpretation from the diagram NA 4 which shows a pressure zone just of the ridge, and higher than the ridge, on the steeper pitched roof

26. if any operable window, sky‐light or ventilation duct opening is within 2,3 m horizontally of a chimney, the outlet of the chimney should be at least 1,0 m above the top of any such opening.

This should be worded to match ADJ and the legend to NA5 in that it states

“Below (on a pitched roof) or within 2300 mm horizontally to an openable rooflight, dormer window or other opening”

The use of the word “below” is essential as if the chimney comes out below the opening then there is a significant risk of nuisance at distances far greater than 2300mm horizontally.

27. For metal systems chimneys, a terminal according to BS EN 1856‐1 can also be used.

I believe that this should say something along the lines of.

“For metal systems chimneys a terminal according to BS EN 1856‐1 and manufactured, or approved, by the system manufacturer must be used”


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28. For a flue serving a solid fuel fireplace recess for an open fire for a solid fuel application, the terminal should preferably be the same cross‐sectional area as the flue and in any case no part of the terminal should be less than 200 mm diameter, or 185 mm square.

It is imperative that the terminal is the same cross sectional area and preferably the same shap as the flue it serves for and open fire and so this should be changed to reflect this and ADJ as well as the main body of the standard.

29. NA.4.8.2 Chimney termination

PARAGRAPH TWO

For masonry chimneys the termination should be constructed of stone or concrete. An ideal termination would incorporate a weathered upper surface and a drip throating which helps to discharge rainwater away from the chimney and assist in the prevention of saturation of that part of the chimney immediately below (see Figure NA.6).

I feel that the traditional use of oversail courses in engineering brick should be covered here, I am aware this was not the case previously but in conservation areas and on masonry chimneys this is still very popular as it looks more in‐keeping and works very well.

30. For metal chimneys the termination is incorporated into the chimney constructed according to BS EN 1856‐1.

I repeat my previous comment on this and feel it should be reworded.

31. For masonry chimneys an alternative type of chimney terminal incorporates a slab or hood supported on piers. The flue terminal should project 20 mm to 25 mm and where the chimney contains two or more flues, the withes between adjacent flues should be carried up to the underside of the slab. The height of the piers should be arranged to provide a total area of opening to the atmosphere of not less than twice the area of the flue(s) in the chimney. The piers should be designed to give a stable structure. The surface of the masonry, through which the flue projects should be flaunched with cement mortar.

The design of a good dovecote is important and requires further detailing. See attached drawing as a sample illustration here.

32. For metal chimneys, a terminal could incorporate a rain cap to protect the flue from rain ingress. This may also include a bird guard. As for masonry chimneys, the height of the rain cap should be arranged to provide a total area of opening to the atmosphere of not less than twice the area of the flue(s) in the chimney.

Should we be ensuring that we have a minimum dimension of the mesh such as “no dimension of any hole in a mesh used as a bird guard should be less than 16mm”.

The dimension is one I have used and has no basis in testing or any standard but if this is left like this we will get chicken mesh used with small holes that will become blocked too easily.

33. NA.5 Masonry chimneys The installation of metal system chimneys may require additional advice, and it is vital to seek the advice of the individual product manufacturer. What on earth is this statement doing under this title?

34. NA.5.2 Durability, strength and stability


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“the height of a chimney should not exceed 4,5 times its least overall horizontal dimension or, in cases where it is adequately stayed, the height above the stay should not exceed this amount” This should either use the words chimney stack i.e. the chimney section above the roof, or state ” that the chimney section above its last intersection with the roof should not exceed”

35. Withes should be not less than 100 mm thick and should be properly bonded to the walls of the chimney

The withes (or midfeathers) are not normally bonded into the chimney walls, especially at stack level. Can we clarify if we mean boded onto or just mortared up to.

36. NA.5.2.1 Structural fire precautions Where the thickness of solid non-combustible material surrounding a flue is less than 200 mm, no combustible material other than a floor or skirting board, dado or picture rail, mantle shelf or architrave should be nearer than 40 mm to the outer surface of the chimney wall.

The wording here seems to allow floor joists to touch the chimney breast rather than just the floor boards or covering, this was not my understanding as these are structural not decorative timbers.

Perhaps wording similar such as

“Where the thickness of solid non-combustible material surrounding a flue is less than 200 mm, no combustible material other than floor boarding and coverings, skirting board, dado or picture rail, and other combustible decorative items should be nearer than 40 mm to the outer surface of the chimney wall.”

37. NA.5.2.3 Provision for cleaning All flues should be easily accessible for inspection and cleaning. For chimneys built of brick, stonemasonry or concrete and designed to serve free-standing appliances not installed in a fireplace recess, e.g. an independent boiler, a cleanout opening with a tight-fitting soot door should be provided. The door should be double-walled and the frame should be carefully built-in and of suitable size to permit easy access to the flue. The cleanout opening and the chamber (usually termed “soot box”) should be located sufficiently below the point of entry of the flue pipe to avoid blockage of the flue pipe outlet by the deposition of soot and fly ash. Care should be taken to avoid forming an unnecessarily large void, as this might interfere with the proper working of the chimney.

This is good but does not include the wording from ADJ that the door should have the same air tightness and thermal conductivity as the flue.

38. NA.5.5 Stonework chimneys The masonry wall surrounding a fireplace recess should be protected by refractory material; if, however, for decorative reasons stone is required, sandstone should be used. Granite, slate and limestone are unsuitable unless protected by a refractory fireback and side cheeks.

This is not to do with changing the standard but should this knowledge be disseminated more widely.

39. Where stone masonry is backed with concrete, construction of the chimney should proceed in lifts or stages corresponding to the sectional length of the lining, concrete being poured between the lining and the stonework, using the lining as permanent shuttering.

If we believe this to still be acceptable should there not be a definition of the concrete that can be used as in all other constructions of chimney we are attempting to insulate the liner. EG perlite concrete or Lecca concrete not just allow the use of dense concrete.


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40. NA.6 Metal chimneys NA.6.1 General Metal chimneys may comprise of a system chimney according to BS EN 1856-1 or of a custom built construction using components according to BS EN 1856-1or BS EN 1856-2.

I understood that BS EN was for flue liners and flue pipes not the chimney system as a whole and so the way I read this I can use components to BS EN 1856 part 2 to construct a chimney, this is not correct necessarily as some components to BS EN 1856 part 2 cannot be used as a chimney.

I am aware that some systems have been approved to both standards and can be used as a chimney system and a connecting flue pipe but not all chimney systems can be used as a connecting flue pipe and not all connecting flue pipes can be used as chimney systems.

If this is to state that a system can be used as a chimney then 1856 part 2 should be removed from this paragraph and introduced when we talk about connecting flue pipes. (they have differing tests I understand)

41. NA.6.2 Designation

This whole paragraph is good as it is but should we ensure that the reader is aware that although the minimum rating is T400 this will not be adequate for all common appliances and reference to the appliance manufacturers’ instructions and Data should be made.

The Stovax instructions are good in that they provide flue gas outlet temperatures for all their solid fuel appliances and some of the more popular ones are above 400⁰C.

42. NA.6.3 Enclosures and shielding of metal chimneys

There is no mention of enclosures and the need for them here.

I feel something along the lines of the following should be added.

“To comply with the requirements of BS EN 15287 part 1 4.3.10 and 4.3.11 will require the flue to be encased where it passes through a living space and shielded where it passes through a storage or roof space to provide adequate protection and clearances from any combustible material that may be placed close to the chimney system. Where a chimney system is encased access for inspection should be provided in accordance with the requirements of NA ###”

43. NA.6.4 Provision for cleaning

See Annex NC.

Annex NC does not discuss provision for cleaning only the frequency, methodology and equipment.

This is one of the most important parts of the document and must be explained clearly as it was with the masonry chimneys.

“All flues should be easily accessible for inspection and cleaning. For steel chimneys systems that are designed to serve free-standing appliances not installed in a fireplace recess, e.g. an independent boiler, or other appliance that cannot be swept or inspected through a cleanout opening with a tight-fitting access cover should be provided. The cover should be to avoid a hot spot on the outer surface of the chimney system, should be part of a purpose made component and of suitable size to permit easy access to the flue. The cleanout opening and the chamber (usually termed “soot box”) should be located sufficiently below the point of entry of the flue pipe to avoid blockage of the flue pipe outlet by the deposition of soot and fly ash. Care should be


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taken to avoid forming an unnecessarily long void below the flue pipe entry, as this might interfere with the proper working of the chimney. It must be possible to sweep the whole of the flue while the appliance is installed.”

44. NA.7 Connecting Flue pipes NA.7.1 Materials Connecting flue pipes should comply with BS EN 1856-2 or chimney components to BS EN 1856-1 may be used.

This is incorrect and does not comply with the existing EN standards.

For a component to be used as a connecting flue pipe it has to be to BS EN 1856 part 2, NOT part 1

The testing in part 2 includes the use of the product in an offset and horizontal plane and as a result will yield a different result to distances to combustible material. This is a very dangerous statemtn to make as using a part 1 component in the horizontal can result in combustible material being placed too close to the connecting flue pipe when in that plane.

Docherty MF system is rated to part 1 and part 2. The G rating to part 1 is 50mm while when tested as a connecting flue pipe to part 2 it is G rated at 70mm this is 40% increase due to the extra heat on the top of the chimney system when in the horizontal plane.

This must be changed if the long horizontals are to be used.

45. NA.7.2 Installation The excessive chilling of the flue gases can lead to the formation of deposits within the flue pipe and chimney and the undesirable condensation of moisture. This will reduce the updraught created by the chimney and may lead to permanent damage or possible blockage. It is, therefore, important to ensure that the length of any flue pipe used to connect an appliance to a chimney be kept as short as practicable. The maximum length should not exceed 2 m. Flue pipes should not be used as a complete chimney; they should only be utilized to connect an appliance to a suitable chimney.

Replace flue pipe with connecting flue pipe in this and the remaining paragraphs to be consistent with the remainder of the standard.

In all HETAS training and in all my own experience we have suggested a maximum length of flue pipe to be 1.2 meters, I would consider 1.5m.

As the efficiency of solid fuel appliances increases, and is likely to have to increase again in the near future, we should be encouraging the use of shorter lengths of flue pipe.

The heat loss from a hot flue pipe is considerable and will affect the draw considerably and I believe allowing 2m will become an issue if not know in the near future.

If we take the 600mm vertical and the 450 horizontal (if this is still accepted) then allowing 1.5 metres would be more than sufficient.

46. Where a flue pipe is used to make a connection between an appliance spigot outlet and a flue in a chimney, there should be no more than two bends in the length of flue pipe. No part of the flue pipe should make an angle of not more than 45° from the vertical. In all cases additional provision should be made for chimney cleaning.

This is now inconsistent with the paragraph further down where a 90 degree change in direction is allowed meaning the flue pipe can be horizontal!


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47. Where it is necessary to discharge a back outlet appliance into a fireplace recess or builder’s opening, the appliance flue spigot outlet should be sealed directly into a vertical register plate, provided there is sufficient space to work. If not, then a short length of flue pipe not exceeding 450 mm in length may be used. The register plate should be firmly fixed and sealed on all sides to the fireplace recess or builder’s opening (see Figure NA.7 a)).

This p[paragraph seems to make no sense at all since figure NA7(a) does not show a register plate and will result in some very strange and in my opinion dangerous installations. See the illustration below.

This in no way describes the installations shown in 7(a) which are far more acceptable, should we be considering this at all

48. For top outlet appliance, the flue connection will not exceed 45º measured from the vertical access and you will not have more than two bends. It is recommended that the flue connecting pipe rises vertically from the appliance where ever practicable. A 90° bend may be used above the top outlet of an appliance providing there is a minimum 600 mm vertical run of flue pipe from the top of the appliance to the bend. A swept 90° bend is preferable for this and a suitable cleaning access is to be incorporated in the bend to enable the full length of the horizontal flue to be easily viewed and swept.

Again this makes no sense. If we cannot exceed 45⁰from the vertical, which I agree with, how can we use a 90⁰ bend. If this is to be retained it must be worded differently and must exclude the use of a 90⁰ elbow.

This in no way prevents me from going the full 1.3 meters horizontal after the bend and so is again incorrect unless this was the intension (which I hope it was not)

Even with the 600 mm and a swept bend, a tee piece plus 2.0m of un‐insulated flue pipe on a 4.5 m effective flue height the Aladin software results in failures in up to 30% of the studies I have done. For this reason this should only be allowed after exhaustive testing has shown that it provides the same level as safety as ADJ or the existing National Annex.

450m


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ADJ States;

I feel it is important that testing is done to ensure that the worst case installation allowed in the National annex is tested against the worst case installation in Approved Document J to prove that the former “achieves a level of performance equivalent to that obtained by following the guidance in the Approved Document”

If we are making changes to a standard we should ensure that they are not detrimental to safety and if at all possible they should improve the safety of the general public the standards are designed to protect.

If the above is read carefully it informs the reader that the method in BS EN 15287 part 1 is an alternative to Document J and not supplementary guidance.

It is imperative that the National Annex and the BS EN is followed in full, including all the calculations required in 15287 if an engineer is to adopt this as an alternative to ADJ and that there is an exclusion from adopting part of one and part of the other.

I have had a calculation done by Ontop A chimney manufacturer, using a Stovax Stockton 5 and a ONTOP flue system as laid out in the following diagram and the statement made was that a 125mm diameter flue is too small and causes resistances in the flue, 150mm diameter flue will pass with almost no margin and 175mm diameter flue fails as the flue gasses drop below dew point and will cause rapid deposits in the chimney. See Appendix A

In the case of the 125 and 150 diameters the problem is the lack of height (4.5m effective flue height was used) and in the case of the 175mm the heat loss through the 2.0m connecting flue pipe was the issue.

49. Connection to rear entry solid fuel appliance may be undertaken with 2 x 45º bends or 90º swept bend for cleaning through the appliance (not 90º right angle) with a debris collecting point, or a 90º T-piece (swept or not) with a debris collecting point acting as the cleaning access (see Figure NA.7 b)). However, this requires sufficient clearance being available to the back of the appliance to enable regular inspection and cleaning of the debris collection point.

This again is poorly worded. If I use two 45 degree bends where is the debris collection point. It does not state that there has to be adequate access to the debris collection point for it to be emptied and so once the flue has been swept, and the collection point full, it is useless.

It suggests that if a 90 degree tee is used that we have to be able to sweep through it, this is not the case. The whole of the flue has to be swept and it has to be possible to empty the collection point. As ADJ is currently written this is possible as in the diagram below.


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Current ADJ arrangements with rear outlet appliances

With the horizontal only 150mm this allows, in most appliances (though not some boiler models) the debris collection space to be reached and cleaned and the remainder of the flue cane be swept up and down from the cleaning access.

Note also that the debris collection area is under the flue so that any fall will be directly into it.

If I wish to use two 45⁰ bends then this does not create a debris collection space and so it should be a 45⁰ bend and a 45⁰ tee. If this is done then there will have to be access to the base of the tee to be able to clean out the debris collection space. If not it becomes full as soon as the chimney is swept and so is useless and creates an unacceptable level of risk.

If access is possible then this arrangement can give sufficient offset to get through a wall or into a fireplace recess.


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Current arrangements with top outlet appliances

If the appliance stands in front of the chimney then the methods shown in the illustration (from the HETAS H003 training manual) can apply.

If the appliance stands in the recess then the process below can apply.

If there is no chimney or recess we either put in a steel chimney system through the house or pas through the wall as shown below.

All these have worked safely for a long time. I believe we should stick with them or ensure any alternatives offered are proven to be as safe by testing and the limits of change set by the results.

It is accepted that the expectations of customers set by the poor advertising

brochures of companies has set a new requirement but this cannot dictate the changes, only proven safe methods that DO NOT INCREASE the risk beyond ADJ should be included in any standard.

We are now allowing some of the following to be done without recourse to individual calculation or generic testing.


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50. NA 7(b)

This shows a swept bend with debris collection space that is almost useless in that the location of the debris collection space is not directly under the vertical and so a fall of deposits will create a partial blockage of the flue before it begins to fill the space. This has been drawn in this location in an attempt to make it cleanable without access to it. See below.

This is not only a poor representation but in my opinion is very misleading. While in discussion re this I had assumed that the dimension would have been from the back of the stove to the vertical section of the flue pipe. As drawn the offset from the stove to the vertical flue can be as much as 650mm.

51. NA.7.3 Fire precautions In order to prevent a chance ignition of combustible material it is essential that any flue pipe be so sited and/or shielded as to reduce the effects of radiated heat transmission to an acceptable level. The manufacturer should declare the distance to walls of combustible material of single wall connecting flue pipes according to BS EN 1856-2. This distance may be either measured according to the standard and declared as G xx M, or if not measured then G xx NM, which is three times the nominal flue diameter without shielding.


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I do not believe this reads correctly. The manufacturer should declare the distance to any combustible material (not just combustible walls) for all connecting flue pipes not just single skin. Note. It should be added that components only tested to BS EN 1856 part 1 cannot be used as connecting flue pipes as they have to be to BS EN 1856 part 2 to be deemed suitable for this purpose.

52. b) any ceiling. The minimum distance from below the ceiling to any single wall connecting flue pipe should be a minimum of 425 mm (see figure NA.8b)

This seems a very arbitrary number and not correct. We either should stick to the three times diameter so 100 and 125mm can be closer if appropriate (although this would normally mean excessive flue pipe as discussed earlier) and 175 and larger should be a greater distance away.

The heat from a pipe is radiated at exactly perpendicular to the pipe (not at an angle that would hit the ceiling unless the flue pipe was not vertical) and the original 150mm given in BS 7566 has never given a problem. Historically I was informed that the 150mm was to allow convected air to cool the outer skin of the chimney system after the insulation had been bridged by the flue pipe adaptor. Again has this been proven to be a requirement or is it just conjecture

53. NOTE Any combustible decorative material used to clad a wall through which a flue pipe is used to connect an appliance to a chimney should be kept well clear of the flue pipe.

Can we really be so precise about the distance from flue pips to ceilings and then use the words ”Kept well away from”. Surely this needs to be more specific and should it be either three times the diameter, Gxx or the 425mm given above.

Is this not important enough to be a paragraph not just a note?

54. Figure NA.8a shows the necessary separation of single wall connecting flue pipes from walls of combustible material.

The effects of radiated heat can be reduced by: a) shielding; b) insulation;

c) the use of insulated chimney components to BS EN 1856-1.

This again changes the criteria without guidance!

Surely this should not only be “from walls of combustible material”, what about kitchen wall cupboards near cooker flue pipes or decorative beams above stoves etc. Why has the wording been changed from that used in ADJ which is very good?

We have added back in the option of insulating the flue pipe, I was of the understanding this was removed from ADJ for a reason, but if you are introducing it again then what grade of insulation and what thickness MUST be used. See ADJ 2002 for the previous advice.

Again the insistence that chimney systems to BS EN 1856 part 1 can be used as connecting flue pipes when there is a specific standard (BS EN 1856 part 2) for this. If the connecting flue pipe is to BS EN 1856 part 1 then it cannot be used in the horizontal plain. Note it is allowed to use part 1 chimney system components in ADJ because there is no acceptance of Horizontal runs in the chimney system.

55. Key 1. Fluepipe 2. Airspace of at least 12 mm between non-combustible shield and non-combustible material 3. Elevation without shield 4. Elevation with shield


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5. Plan without shield 6. Plan with shield

Item 2 on this Key is wrong. It should read “Airspace of at least 12mm between non‐combustible shield and COMBUSTIBLE material.

56. Figure NA.8b – minimum distance of projection of a chimney below the ceiling when connecting to a single wall connecting flue pipe

See Note 52 above.

57. NA.7.4 Provision for cleaning Any flue pipe should be erected in such a way that it can be swept through its length without difficulty or causing damage to any part. A sealed cleaning door having a durable fixing should be fitted if access cannot be achieved through the appliance or via a suitable soot door within the chimney that allows easy access to the flue pipe. .

This is not correct again because it does not reference the need for the cleaning access to have the same air tightness and thermal conductivity as the component it is a part of.

“A sealed cleaning door having a durable fixing, that has the same air tightness and thermal conductivity as the component it is fitted in, of sufficient size to allow a suitable brush and rods to be used, should be fitted to the connecting flue pipe if suitable access to all of the connecting flue pipe cannot be achieved through the appliance or via a suitable soot door within the chimney that provides easy access for suitable equipment for cleaning to the connecting flue pipe.”

58. An adjustable length (disconnected section) can be used for cleaning access

If the flue appliance is disconnected from the chimney system by breaking the seals on the connecting flue pipe then reconnecting is a reinstallation and the chimney should be tested for suitability and continued good condition prior to the reconnection.

This may require the person to be Registered Competent or apply for building regulations approval.

In ADJ it states that the flue must be able to be cleaned when the installation is complete and once the telescopic pipe has been disconnected the installation is no longer complete.

59. NA.8.1.1 Visual inspection of metal system chimney within enclosures Where practical, the length of the chimney may be inspected after installation, from below by removal or looking through the firestop plate or register plate, or by inspection looking down from above in the roof space, possibly by the use of a camera.

When discussed this was to be if possible to gain access to, and see sufficiently through, a firestop.

ADJ states that there must be sufficient access to inspect the joints in the flue and to ensure it is adequately supported. I am unhappy that when an inspection of a completed installation is required (check for compliance or for a survey prior to a house purchase) that the standard should expect the surveyor to remove an important safety component for access. The option to allow the remove of a fire stop should be removed for safety purposes and to avoid dispute as to whether it was replaced correctly.

If it is not possible to see through a firestop or stops sufficiently to inspect the distance to combustibles, the support and the joints then an access panel must be provided.

60. Where it is impractical to use the above methods, a 100 mm square access door should be created to allow for inspection by other means (e.g. with a torch and mirror). NA.8.2 Connecting Flue pipes.


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Again the wording of this is not strong enough and confusing.

“Where it is impractical to use the above methods, an access door or panel must be created of at least 100 mm by 100mm to allow for inspection by other means (e.g. with a torch and mirror). Where required to enable full inspection of all joints, distances to combustible material, support and firestops either a larger Access door or panel or more than one access door or panel may be required.

61. NA.8.2 Connecting Flue pipes

This seems to have been tagged on the end by mistake or there is a whole section missing regarding the inspection of joints etc. in connecting flue pipes.

I believe there should be a section NA 8.2 and it should say

“Other than for an inset appliance all joints in connecting flue pipes, between connecting flue pipes and the appliance outlet spigot and between the connecting flue pipe and the chimney system must be able to be inspected when the appliance and chimney are tested and commissioned and during maintenance to ensure there has been no degradation in the jointing compounds used.”

62. NA.8.3 Commissioning NA.8.3.1 Introduction The function of a chimney system is to provide an unimpaired passage for the complete evacuation of the products of combustion generated by the burning of a fuel at its base. Any chimney system designed, constructed or assembled as recommended by this National Annex NA should satisfy this function.

This is an incomplete description of the function of a chimney and will lead to the believe that any shaft containing a flue will be adequate.

The chimney and flue have other functions as indicated in Building Regulation J The requirements J1 – J4.

I believe this should be changed to reflect this to ensure the commissioning inspection reflects these requirements. A suggestion would be;

“The function of a chimney system is to provide an unimpaired passage for the complete evacuation of the products of combustion generated by the burning of a fuel at its base, to provide adequate negative pressure to deliver the correct amount of air for complete combustion and to provide adequate protection from accidental ignition and fire spread within the property. Any chimney system designed, constructed or assembled as recommended by this National Annex NA, in conjunction with the details in the main body of the standard should satisfy this function.

63. The success of any product constructed or assembled on site relies on the skill of the person(s) undertaking the work. By following the recommendations made within this National Annex NA and in the manufacturer instructions, dangerous consequences can be avoided. It is therefore recommended that all newly constructed or assembled chimney systems should be checked for blockage and soundness.

This appears to be forgetting that the National Annex is only one part of the standard and that the standard has to be considered as a whole not the National Annex as a stand‐alone document.

64. The tests described in NA.8.3.2, NA.8.3.3 and NA.8.3.4 are designed to identify any major blockage or flue gas leakage on a new chimney. It is not possible to quantify the smoke test as during normal operation a chimney is under a small negative pressure whilst a positive


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pressure is created by the smoke pellets. Any leakage of smoke observed during the test should be investigated and the test repeated after the necessary remedial action has been carried out. NA.8.3.2 Coring ball test for masonry chimneys.

Again the editing has gone wrong. There should be a section NA.8.3.2 and this should not be a sentence at the end of this paragraph

In addition the smoke pellet does not create a pressure in this test. If the test is done correctly we wait until the smoke reaches the chimney pot before bagging of the top of the flue. This relieves any pressure generated by the expansion of the chemicals in the pellet. I have twice demonstrated this, once while at British Coal and once to ODPM, as it was then, at the NACS Centre. Any force is only generated by the wish of the air in the flue to rise once the flue has been warmed for only ten minutes by a blow lamp. The temperature in the flue is well below that during the operation of the appliance and as a result the pressure variation between the inside and outside of the flue is only a fraction of that while the fire is lit.

The smoke coming from the chimney is an indication of the cold air being drawn into the flue while in operation (though the volume of smoke coming out will be far less than the air entering while the fire is lit). This indication will help to give an understanding of the risks if a cold plug in the flue due to excessive cooling and give an indication against which to make a risk assessment.

If while the fire is alight a cold plug is generated, due to excessive leakage in to the flue from freezing external conditions, then the amount of leakage from the flue below this point will be many times greater than that seen in the test.

65. NA.8.3.3 Smoke test (masonry chimneys)

This test may be required for a steel chimney system to ensure the joints in the connecting flue pipe and between the connecting flue pipe and the appliance and chimney system, have been made correctly. I believe this test should not be limited to flues in masonry chimneys.

66. The appliance, if fitted, should not be alight at the time of test. Before commencing, the chimney flue should be warmed by a gas blow lamp or similar heating device for about 10 minutes. The ashpit door of the appliance and thermostat (if fitted) should be in the closed position. Any soot doors or flue pipe access doors should be closed.

Punctuation or something has gone wrong here because as worded I could, or perhaps should, leave the fire door to the stove open. It should perhaps read “The ashpit, fire door and any closable air inlet to the appliance should be in the closed position”

THIS IS SAFETY RELATED AS THIS TEST MUSTT BE CARRIED OUT CORRECTLY BEFORE THE APPLIANCE IS PUT INTO USE!

67. The chimney breast and surrounding walls should then be observed at ground level, first floor level, roof space level and terminal level to check for major smoke leakage. As this may occur some distance from the original fault, particular attention should be taken at barge overhangs to end of terrace dwellings and at eaves for leakage from cavities. The smoke test should be allowed to continue for at least 5 minutes.

I believe the wording should read “to check for smoke leakage” not Major smoke leakage. As discussed above even a slight smoke leakage from a chimney stack can have a major effect on the performance and safety of a flue. If it is visible in daylight despite the relatively low density of smoke and the very low pressures then this should be addressed.


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68. NOTE 2 The smoke test should be carried out using suitable smoke pellets. The minimum performance of a pellet should be one, which the pellet manufacturer claims generates 5 m³ of smoke in 30 seconds burn time.

This is the type of small smoke pellet used for a spillage test on a gas fire.

The pellets used for this are 60 second burn and produce in the region of 12 – 15m³


69. NA.8.3.4. Flue flow test for metal chimneys (draw test)

This is not a test just for steel chimneys, this flue flow test or draw test (I like the name and the fact that it is not being called a spillage test.

This must be done on any chimney when the appliance has been fitted, irrespective of the construction of the chimney.


70. The appliance, if fitted, should not be alight at the time of the test. Before commencing, the chimney flue should be warmed by a gas blow lamp or similar heating device for about 10 minutes. The ashpit door of the appliance and thermostat (if fitted) should be in the closed position. Any soot doors or flue pipe access doors should be closed.

This paragraph is wrong! Any air control to the appliance must be fully open and if the manufacturer claims the appliance can be used with the doors open then these must also be open.

71. Two smoke pellets should be placed in the appliance firebox or the bottom of the chimney or the appliance recess and ignited. Open the combustion air controls. When smoke starts to form, the smoke should be allowed to drift upwards. The test is satisfactory if, while the smoke pellet is burning, there is no spillage of smoke at the heating appliance, no seepage of smoke over the length of the flue and there is discharge of smoke from the terminal.

This description is inadequate; there is no discussion re windows, doors, vents or extract ventilation. There is no comment about checking for adequate ventilation by opening a window and checking for increased evacuation speed etc.

The details from the H003 manual are far better and as described this test is totally inadequate and dangerous.


72. NC.1 Cleaning NC.1.1 Introduction Any flue pipe connecting an appliance to a chimney may be of a smaller cross-sectional area than the chimney. It is therefore advisable to clean any flue pipe at intervals not exceeding one month. There will be circumstances when this period will need to be reduced; this should be determined by user experience.


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It is not strictly true that “Any” connecting flue pipe may be smaller. This should perhaps read “Many”

73. Fly ash may be entrained in the flue gases which may deposit out at any point within the chimney or flue pipe.

I Feel there should be an addition to this stating “ this is particularly the case in any offsets or horizontal runs.”

74. using well seasoned wood air dried for at least 6 months, preferably 12 months

It is an industry accepted statement to say at least 12 ‐18 months preferably 2 years.

75. When using a metal chimney, please check the manufacturer recommendations to see if it is suitable to use with a particular type of fuel.

This statement should have been entered at the start of the Metal chimney section not here but a statement that says to check which brushes and cleaning equipment can be used in Flexible flue liners and metal chimney systems would be a good idea.

76. NC.1.3 Equipment

The rods used for chimney cleaning are normally manufactured from cane or polypropylene and are available in a range of lengths. These components should be strong, yet flexible enough to bend as much as 45°.

If the acceptance of 90⁰ bends is agreed than this needs changing to say 90⁰

77. The brushes and rods described above are unsuitable for cleaning flue pipes. It is recommended that a spiral wound bristle brush designed for such a purpose be used in this part of the operation.

This must be changed because if it is not then many of the installations this standard allows are not possible. Many appliances are designed to be swept through and so they will sweep through the flue pipe. If the 2.0m of flue pipe is allowed, along with 90⁰ bends then this flue pipe should be bracketed if it is to be swept through.

78. Inset or free-standing room heaters with or without a boiler that meet the required standards set by the Heating Equipment Testing and Approvals Scheme (HETAS) can be swept by passing a spiral wound brush from the firebox to the chimney.

This is no longer the case, there are boiler models in the guide that cannot be swept through the appliance.

79. it is therefore necessary either to remove the appliance prior to sweeping

ADJ does not allow this as it will require the sweep to refit the appliance and this may require registration or building control.

ADJ states that it must be possible to sweep the whole of the flue while once the installation is complete and I believe this should be kept the case in this document.

THIS IS SAFETY RELATED

80. The size and type of construction will influence the type of equipment to be used. The diameter of the brush head should be compatible with the internal diameter of the


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chimney flue as sweeping with too small a brush may not be effective and too large may cause damage.

Should the word diameter be changed for dimension as there are square flues.

81. Masonry chimneys can be cleaned using any of the brush heads given in NC.1.3. Generally a diameter of 50 mm above chimney size is suitable.

This is only the case with round flues. Rectangular flues require a brush that is 50mm larger than the longest length across the diagonal, e.g. 225 x 225mm flue requires a 350mm diameter brush.

82. NC.1.5 Chimney fires

If a chimney fire does occur, professional advice should be sought regarding the condition of the chimney. If the integrity is in doubt, the manufacturer should be consulted.

In the case of a masonry or custom made chimney a structural engineer should be consulted.

83. NC.2 Maintenance

Are we to assume that there is no need to examine or check a metal chimney system at all? There is no section here to cover supports, corrosion potential, flashing, charing of combustible material, leakage from joints and staining etc.

Appendix1

1Ontop B.V. / / Pr.Nr.:Stockton 5 wood stove

Mick Waumsley

Installation place of system

Date : 03.07.2012 User : Ruud de Voogd Project : Stockton 5 wood stove

Restrictive, house chimney+TÜV-presettings

negative pressure chimneyinside building, wet operating method, combustion air from inside

Stockton 5-wood (23,1% moisture)4,9 kW

ONTOP B.V.ONTOP Metaloterm © MF (CE 0432-BPR-119991)0,149 m (round)

ONTOP B.V.ONTOP Metaloterm © MF (CE 0432-BPR-119991)0,149 m (round)

Ontop B.V.Ruud de VoogdOude Veerseweg 234332 SH MiddelburgTelefon :+31 118 689 962Telefax :+31 118 689 999Mobil :+31 6 534 313 [email protected] - www.metaloterm.com www.metaloterm-marine.co

Ontop B.V. - Oude Veerseweg 23 - 4332 SH Middelburg

Program modus :

Calculation for :Run :

Heat appliance :- Type :- Fuel :

- Nominal heat output :

Connection pipe :- Type :

- cross-section :

Chimney :- Type :

- cross-section :

Calculation of inside dimensionsof chimneysaccording to EN13384 part 1(01.03)

NoticeThe stove will operate okay with a ø150mm flue but it's still not really convincing. ø130mm is to small

resulting in to much resistance and a ø180mm is to big because the flue gas velocity drops down to allmost nothing resulting in a lot of soot build-up in the chimney.

Basically the required 12.5 Pa flue draft and the short flue length is disturbing this situation. Make sure there is low resistance in the air supply.


Functional proof

Proof

Pipe

Chimney

Diverse

Stockton 5wood (23,1% moisture)Qn= 4,9kWTw= 369°CPw= 12,5Pa

Section 1

ONTOP Metaloterm © MFLv= 0,4mHv= 0m

Dhv= 0,149mZeta= 0,00

Alpha(a)= 8,00

Section 1

ONTOP Metaloterm © MFL= 5mH= 4,5m

Dh= 0,149mLpb= 5,0m

Zeta= 3,30

Result

Tiob= 76,00°CTob= 148,00°CTg= 0,00°CPz= 19,98Pa

Pze= 15,50PaPB= 3,00Pa

F.load/P.load

Pz - Pze= 4,48PaPz - PB = 16,98Pa

zem - Pzm= 0,00PaTiob - Tg= 76,00°C

The conditions according to EN13384/1 are fulfilled !

Pressure requiement :Temperature requirement :

Evaluation of the functional proof

yesyes

Functional proof values

Negative pressure at flue gas inlet into chimney :required draught at flue gas inlet into chimney :

Inner wall temperature chimney outlet :Flue gas temperature chimney outlet :

Flue gas velocity :Temperature limit :

19,9815,5

761480,19

0

PaPa°C°Cm/s°C


Heat appliance

Producer Stockton 5TypeConstr./input yearDescription woodburning stoveFuel wood (23,1% moisture)Nominal heat output kW 4,9 Efficiency % 75 Furnace output kW 6,53 Concentration by volume of CO2 % 8 Flue gas mass flow kg/h 8,32 Flue temperature °C 369 required delivery pressure Pa 12,5 Ratio air/flue gas 3,18 Flue gas connection-form round- Diameter m 0,125 INDIVIDUAL COEFFICIENTS FOR R Number Angle ZetaAdaptor tapered 1 60 0,28

Connecting pipe

Producer ONTOP B.V.Design ONTOP Metaloterm © MF (CE 0432-BPR-119991)effective length m 0,4 effective height m 0 Form cross sect. round- Diameter m 0,149 Thermal resistance m²K/W 0,554 Wall thickness m 0,026 Mean roughness m 0,001 effective length in the open air m 0 effective length in cold area m 0 effective length in heated rooms m 0 effective length in boiler room m 0,4 COURSING CTC TR d [m]ONTOP Metaloterm © MF 0,554 0,026 Sum of individual coefficients of resis 0

Chimney

Producer ONTOP B.V.Design ONTOP Metaloterm © MF (CE 0432-BPR-119991)effective length m 5 effective height m 4,5 Form cross sect. round- Diameter m 0,149 Thermal resistance m²K/W 0,554 Wall thickness m 0,026 Mean roughness m 0,001 effective length in the open air m 1,5 effective length in cold area m 0 effective length in heated rooms m 0 effective length in boiler room m 3,5 COURSING CTC TR d [m]ONTOP Metaloterm © MF 0,554 0,026 INDIVIDUAL COEFFICIENTS FOR R Number Angle ZetaT-piece 1 90 1,2


ONTOP-bow 2 45 0,8 Sum of individual coefficients of resis 3,3

Outlet

MFK (Rg.h.m Windf.) Zeta 1,3 0 Velocity pressure Pa 0 Region Inland regions (>20km form the coast)

Installation room

INSTALLATION ROOM Heating roomrequired delivery pressure supply air Pa 3

Basic data of calculation

Geodetic height m 50 flow safety coefficient 1,5

Heat appliance

Flue gas connection (FL/setting value)mean density kg/m³ 0,521 mean flue gas velocity m/s 0,3615ZETA-value 0,28 Resistance pressure Pa 0,0143

Connecting pipe

Temperature equilibrium/without temperature equilibrium (FL/setting value)dynamic viscosity * 1E-6 * Ns/m 29,1819 28,9538mean density kg/m³ 0,5322 0,5381Gas constant J/(kg*K) 288,2304 288,2304mean flue gas velocity m/s 0,2491 0,2464Reynolds number 2300 2300 Thermal conductivity flue gas W/(m*K) 0,0454 0,045 specific heat capacity J/(kg*K) 1124,432 1122,3491Prandtl-number 0,7226 0,7228Friction coefficient of pipe-plain 0,0473 0,0473- rough 0,0525 0,0525Nusselt-number 11,8888 11,8901Coefficient of heat transmission, insid W/(m²*K) 3,6233 3,5877Coefficient of heat transmission, outs W/(m²*K) 8 8 Coefficient of heat transmission W/(m²*K) 1,0839 1,661 Coefficient of cooling 0,0781 0,1199Ambient air temperature °C 15 15 mean flue gas temperature °C 355,5302 348,6008Outlet temperature °C 342,4064 329,0006Density outlet kg/m³ 0,5435 0,5556Flue gas velocity outlet m/s 0,2439 0,2386Inner wall temperature inlet °C 263,1074Outer wall temperature inlet °C 50,5519Srad 2 - layer 2 °C 0 - layer 3 °C 0 - layer 4 °C 0 - layer 5 °C 0


Inner wall temoerature outlet °C 244,4688Outer wall temperature outlet °C 47,8812- layer 2 °C 0 - layer 3 °C 0 - layer 4 °C 0 - layer 5 °C 0 PressuresResistance pressure friction a. form. Pa -0,0148Change of pressure by change of vel Pa -0,0183Resistance pressure Pa -0,0148Static pressure Pa 0

Chimney

Temperature equilibrium/without temperature equilibrium (FL/setting value)dynamic viscosity * 1E-6 * Ns/m 24,8058 23,5954mean density kg/m³ 0,6631 0,7073Gas constant J/(kg*K) 288,2304 288,2304mean flue gas velocity m/s 0,1999 0,1874Reynolds number 2300 2300 Thermal conductivity flue gas W/(m*K) 0,0374 0,0353specific heat capacity J/(kg*K) 1089,9589 1082,1533Prandtl-number 0,7241 0,7235Friction coefficient of pipe-plain 0,0473 0,0473- rough 0,0525 0,0525Nusselt-number 8,594 8,5915Coefficient of heat transmission, insid W/(m²*K) 2,1539 2,035 Coefficient of heat transmission, outs W/(m²*K) 12,5 12,5 Coefficient of heat transmission W/(m²*K) 0,928 1,2531Coefficient of cooling 0,8623 1,1727Ambient air temperature °C 6 15 mean flue gas temperature °C 231,4226 199,8804Outlet temperature °C 148,0323 112,1941Density outlet kg/m³ 0,7944 0,8682Flue gas velocity outlet m/s 0,1669 0,1527Inner wall temperature inlet °C 197,463 Outer wall temperature inlet °C 24,5136Srad 1 - layer 2 °C 0 - layer 3 °C 0 - layer 4 °C 0 - layer 5 °C 0 Inner wall temoerature outlet °C 86,8365Outer wall temperature outlet °C 13,8165- layer 2 °C 0 - layer 3 °C 0 - layer 4 °C 0 - layer 5 °C 0 PressuresResistance pressure friction a. form. Pa 0,0629Change of pressure by change of vel Pa -0,0057Resistance pressure Pa 0,0886Static pressure Pa 20,0733

Outlet

Temperature (FL/setting value)Coefficient of heat transmission, outs W/(m²*K) 23 Coefficient of heat transmission : W/(m²*K) 0,9519


Umgebungslufttemperatur °C -15 Inner wall temperature : °C 75,9782Temperature limit : °C 0 PressuresNegative pressure flue gas inlet : Pa 19,9847req. negative pressure flue gas incomPa 15,4996required delivery pressure supply air Pa 3

Appendix2

Dear Mick, Please have a look at the attached drawing and tell me if the sizes are what you had in mind. It may be that the part lengths have to be modified to fit in with standard lengths. These parts would be single wall connecting flue pipe to be supplied by you. We could carry out a test run with a wood burning appliance connected directly to a straight twin wall insulated chimney overall height 4.5m. With the appliance on scales a burning rate could be established and a draught measurement recorded. Temperatures would be recorded at the points marked with letters. Appliance settings would be left in one position throughout the tests to represent the nominal output over an hour burn period. Once these parameters had been established the flue could be modified to the top outlet and then rear outlet on the drawing and the appliance run at the same air settings again with the temperatures and draught recorded. This will give a comparison of performance over the three different flue connections and will show the temperature drop from the appliance outlet A to the point where it enters the chimney C. For the system chimney temperatures could also be recorded further up if required. These tests will be performed under natural draught conditions. It is not proposed at this time to use a brick or clay lined chimney but if required a proposal could be made. If this is acceptable, I estimate this programme of work, with reporting will take 5 days and will cost £4100 plus vat. This will require you to provide the necessary connecting flue pipe to connect the appliance and for you to arrange the loan of a suitable wood burning appliance with an outlet to match the connecting flue pipe. I would suggest an appliance with a nominal output of between 5 and 8 kW would be sufficient. Only one diameter of connecting flue pipe is covered in this proposal to be nominated by you. The system chimney we have is 150mm diameter. We could start the work within the next three weeks, subject to being in possession of the materials to be supplied by you. In any reply please quote proposal number KGaC 8759. Payment terms are 50% on purchase order and 50% prior to the issue of the report. Invoices are to be paid within 30 days of issue. Subject to our standard terms and conditions, a copy is available upon request. I hope this is sufficient information for you but if you have any questions or further requirements for the testing programme please come back to me. With kind regards

Gregory Brown

Construction Projects Manager

Kiwa GASTEC at CRE

The Orchard Business Centre, Stoke

Orchard

Cheltenham, GL52 7RZ, UK

T +44 (0)1242 677877

M +44 (0)7792 396889

F +44 (0)1242 676506

Kiwa Ltd is registered in England and Wales no. 3473056

Visit our website: www.kiwa.co.uk Disclaimer: www.kiwa.co.uk/disclaimer Registered office as above

http://www.kiwa.co.uk/

http://www.kiwa.co.uk/disclaimer/

Appendix3

12

TECHNICAL SPECIFICATION

STOCKTON

Model

Stockton 3 - 7118

Stockton 4 - 7101/7102

Stockton 5 - 7119/7160/7108/7127/Stockton 5ML - 7130

Stockton 6 - 7100/7162/Stockton 6HL - 7117

Stockton 7 - 7120/7163

Stockton 8 - 7103/7104/7105/7113/7113LC/7113HC/7114/7128

Stockton 11 - 7106/7106LC/7106HC/7116/7116LC/7116HC

Stoc

kton

4

Stoc

kton

3

Stoc

kton

5

Stoc

kton

6

Stoc

kton

6H

L

Stoc

kton

7

Stoc

kton

8

Stoc

kton

8 S

L

Stoc

kton

11

Nominal Heat Output Wood

Wood

Solid Fuel

Solid Fuel

Wood

Wood Seasoned wood (less than 20% moisture content)

Briquette smokeless fuel suitable for closed appliances. (Not Stockton 11)(Ancit - Phurnacite - Taybrite - Homefire ovals)

Solid Fuel

Solid Fuel

kW

g/s

kW

mm Wg

inch Wg

g/s

°C

°C

mm

inch

kg

4.0

3.8

4.0

1.25

0.05

2.9

369

369

125

83

3.75

3.8

3.75

1.25

0.05

2.9

408

408

125

76

4.9

2.6

4.9

1.25

0.05

3.2

369

369

125

120

6.0

5.2

6.0

1.25

0.05

6.2

427

427

125

140

6.0

5.2

6.0

1.25

0.05

6.2

427

427

125

150

7.0

6.1

7.0

1.25

0.05

6.8

446

446

150

130

7.0

7.0

7.0

1.25

0.05

7.3

446

446

150150

120

11.40

N/A

1.25

0.05

N/A

453

N/A

180

55 5 6 6 6 66 7

160

8.0

7.0

8.6

1.25

0.05

7.3

446

446

140

All FuelsFlue Draught at Nominal Heat Output

Flue Gas Mass Flow

Flue Gas Temperature at Spigot/Socket

Flue Outlet Size (Top or Rear Option)

Weight

Recommended Fuels

As tested to the requirements of EN 13240 for intermittent operation.

Stoc

kton

5M

L

11.04.9

2.6

4.9

1.25

0.05

3.2

369

369

125

5

Constructional = CH12mm Hearth = 12mmMinimum Hearth Type Required

100

CH CH CH 12mm CH 12

mm CH CH CH CH

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