EN 13384-2:2015+A1:2019
(Main)Chimneys - Thermal and fluid dynamic calculation methods - Part 2: Chimneys serving more than one combustion appliance
Chimneys - Thermal and fluid dynamic calculation methods - Part 2: Chimneys serving more than one combustion appliance
This part of EN 13384 specifies methods for calculation of the thermal and fluid dynamic characteristics of chimneys serving more than one heating appliance.
This part of EN 13384 covers both the cases, either
a) where the chimney is connected with more than one connecting flue pipe from individual or several appliances in a multi-inlet arrangement; or
b) where the chimney is connected with an individual connecting flue pipe connecting more than one appliance in a cascade arrangement.
The case of multiple inlet cascade arrangement is covered by the case a).
This part of EN 13384 deals with chimneys operating under negative pressure conditions (there can be positive pressure condition in the connecting flue pipe) and with chimneys operating under positive pressure conditions and is valid for chimneys serving heating appliances for liquid, gaseous and solid fuels.
This part of EN 13384 does not apply to:
- chimneys with different thermal resistance or different cross-section in the various chimney segments. This part does not apply to calculate energy gain;
- chimneys with open fire places, e.g. open fire chimneys or chimney inlets which are normally intended to operate open to the room;
- chimneys which serve different kinds of heating appliances regarding natural draught, fan assisted, forced draught or combustion engine. Fan assisted appliances with draught diverter between the fan and the chimney are considered as natural draught appliances;
- chimneys with multiple inlets from more than 5 storeys. (This does not apply to balanced flue chimney.);
- chimneys serving heating appliances with open air supply through ventilation openings or air ducts, which are not installed in the same air supply pressure region (e.g. same side of building).
For positive pressure chimneys this part only applies if any heating appliance which is out of action can be positively isolated to prevent flue gas back flow.
Abgasanlagen - Wärme- und strömungstechnische Berechnungsverfahren - Teil 2: Abgasanlagen mit mehreren Verbrennungseinrichtungen
Dieser Teil der Normenreihe EN 13384 legt Berechnungsverfahren für die wärme- und strömungstechnischen Eigenschaften von Abgasanlagen mit mehreren !Verbrennungseinrichtungen" fest.
Dieser Teil der EN 13384 umfasst zwei Fälle:
a) senkrechte Teile von Abgasanlagen, in die mehrere Verbindungsstücke von einzelnen oder mehreren zusammengefassten Verbrennungseinrichtungen münden; oder
b) senkrechte Teile von Abgasanlagen, in die ein einzelnes Verbindungsstück mündet, das mehrere Verbrennungseinrichtungen in Kaskadenschaltung verbindet.
Der Fall des Anschlusses mehrerer Kaskadenschaltungen ist durch Fall a) abgedeckt.
Dieser Teil von EN 13384 befasst sich mit Unterdruckabgasanlagen (im Verbindungsstück können Überdruckbedingungen herrschen) sowie mit Überdruckabgasanlagen und gilt für Abgasanlagen mit !Verbrennungseinrichtungen" für flüssige, gasförmige und feste Brennstoffe.
Dieser Teil der Normenreihe EN 13384 gilt nicht für:
— Abgasanlagen mit unterschiedlichen Wärmedurchlasswiderständen oder unterschiedlichen Querschnitten in den verschiedenen Abschnitten der Abgasanlage. Energiegewinne werden durch diesen Teil der Normenreihe nicht berücksichtigt;
— Abgasanlagen für offene Feuerstätten, z. B. offene Kamine oder Abgaseinführungen in die Abgasanlage, die bestimmungsgemäß offen im Raum betrieben werden;
— Abgasanlagen für verschiedene !Verbrennungseinrichtungen" mit Unterdruckbetrieb (Naturzug), Gebläseunterstützung oder Verbrennungskraftmaschine. Gebläseunterstützte Abgasanlagen mit einer Nebenluftvorrichtung zwischen Gebläse und Abgasanlage sind als Naturzugkessel anzusehen;
— Abgasanlagen mit Mehrfachanschlüssen aus mehr als 5 Geschossen (dies gilt nicht für Luft-Abgas-Systeme);
— Abgasanlagen für !Verbrennungseinrichtungen", denen die Zuluft über Öffnungen ins Freie oder Zuluftleitungen zugeführt wird, die sich druckmäßig nicht im gleichen Luftverbund befinden (z. B. auf der gleichen Seite des Gebäudes).
Bei Überdruckabgasanlagen gilt dieser Teil nur dann, wenn alle nicht in Betrieb befindlichen !Verbren-nungseinrichtungen" sicher abgesperrt werden können, um einen Abgasrückfluss zu verhindern.
Conduits de fumée - Méthodes de calcul thermo-aéraulique - Partie 2: Conduits de fumée desservant plus d'un appareil à combustion
La présente partie de la norme EN 13384 définit des méthodes de calcul des caractéristiques thermoaérauliques de conduits de fumée desservant plusieurs générateurs de chaleur.
Cette partie de la norme EN 13384 traite des deux cas suivants :
a) cas où le conduit d’évacuation est relié à plusieurs conduits de raccordement partant d'un ou de plusieurs générateurs de chaleur dans un système multi-entrée ou
b) cas où le conduit d’évacuation est relié à un seul conduit de raccordement reliant plusieurs générateurs de chaleur dans un système en cascade.
Le cas du système multi-entrée en cascade est couvert par le cas a).
La présente partie de l'EN 13384 traite des conduits de fumée fonctionnant dans des conditions de pression négative (il peut y avoir une pression positive dans le conduit de raccordement) et des conduits de fumée fonctionnant dans des conditions de pression positive ; elle s'applique à des conduits desservant des générateurs de chaleur pour combustibles liquides, gazeux et solides.
Cette partie de la norme EN 13384 ne s'applique pas aux conduits de fumée suivants :
conduits de fumée présentant une résistance thermique différente ou une section différente dans les différents segments. Cette partie ne s’applique pas pour le calcul du gain énergétique ;
conduits avec foyer ouvert, par exemple conduits de cheminées d'appartements ou entrées de conduits de fumée normalement conçues pour fonctionner ouvertes sur la pièce ;
conduits desservant différentes sortes de générateurs de chaleur : appareils à tirage naturel, ventilés, à tirage forcé ou à moteur à combustion. Les appareils ventilés possédant un coupe-tirage entre le ventilateur et le conduit d’évacuation sont considérés comme des appareils à tirage naturel ;
conduits multi-entrées desservant plus de 5 étages. (Ceci ne s'applique pas aux conduits d’évacuation des produits de combustion et d’amenée d’air comburant) ;
conduits desservant des générateurs de chaleur alimentés à l'air libre par l'intermédiaire d'ouvertures de ventilation ou de conduits aérauliques, qui ne sont pas installés dans la même zone de pression d'alimentation en air (par exemple du même côté du bâtiment) ;
Pour les conduits de fumée sous pression positive, cette partie ne s’applique
Dimniki - Računske metode termodinamike in dinamike fluidov - 2. del: Dimniki za več kot eno ogrevalno napravo
Ta del evropskega standarda EN 13384 določa računske metode termodinamike in dinamike fluidov v dimnikih za več kot eno ogrevalno napravo.
Ta del standarda EN 13384 se uporablja:
a) kadar je dimnik povezan z več kot eno priključno dimno cevjo iz ene ali več naprav v inštalaciji z več dovodi; ali
b) kadar je dimnik povezan z eno priključno dimno cevjo, ki povezuje več naprav v kaskadni inštalaciji.
Primer kaskadne inštalacije z več dovodi je zajet v primeru a).
Ta del standarda EN 13384 obravnava dimnike, ki delujejo pod pogoji z negativnim tlakom (v priključni dimni cevi je lahko pozitiven tlak) in dimnike, ki delujejo pod pogoji s pozitivnim tlakom, ter se uporablja za dimnike za ogrevalne naprave na tekoča, plinasta in trdna goriva.
Ta del standarda EN 13384 se ne uporablja za:
– dimnike z različno toplotno upornostjo ali različnim prerezom v različnih segmentih dimnika. Ta del se ne uporablja za izračun pridobljene energije;
– dimniki z odprtimi kamini, npr. odprti kamini ali dovodi dimnika, ki so običajno odprti v prostor;
– dimniki za različne ogrevalne naprave glede na naravni vlek, s pomočjo ventilatorja, prisilni vlek ali motor z zgorevanjem. Ogrevalne naprave, ki delujejo s pomočjo ventilatorja in imajo med ventilatorjem in dimnikom preusmerjevalnik vleka, se štejejo za naprave z naravnim vlekom;
– dimniki z več dovodi iz več kot 5 nadstropij (to ne velja za tlačno izravnane dimnike);
– dimniki za ogrevalne naprave z odprtim dovodom zraka skozi prezračevalne odprtine ali zračne kanale, ki niso nameščeni v istem tlačnem območju dovoda zraka (npr. na isti strani zgradbe).
Za dimnike s pozitivnim tlakom se ta del standarda uporablja samo, če je mogoče ogrevalno napravo, ki ne deluje, pozitivno izolirati, da se prepreči povratni tok dimnih plinov.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-september-2019
Nadomešča:
SIST EN 13384-2:2015
Dimniki - Računske metode termodinamike in dinamike fluidov - 2. del: Dimniki za
več kot eno ogrevalno napravo
Chimneys - Thermal and fluid dynamic calculation methods - Part 2: Chimneys serving
more than one heating appliance
Abgasanlagen - Wärme- und strömungstechnische Berechnungsverfahren - Teil 2:
Abgasanlagen mit mehreren Feuerstätten
Conduits de fumée - Méthodes de calcul thermo-aéraulique - Partie 2: Conduits de
fumée desservant plus d'un appareil de chauffage
Ta slovenski standard je istoveten z: EN 13384-2:2015+A1:2019
ICS:
91.060.40 Dimniki, jaški, kanali Chimneys, shafts, ducts
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 13384-2:2015+A1
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2019
EUROPÄISCHE NORM
ICS 91.060.40 Supersedes EN 13384-2:2015
English Version
Chimneys - Thermal and fluid dynamic calculation
methods - Part 2: Chimneys serving more than one heating
appliance
Conduits de fumée - Méthodes de calcul thermo- Abgasanlagen - Wärme- und strömungstechnische
aéraulique - Partie 2: Conduits de fumée desservant Berechnungsverfahren - Teil 2: Abgasanlagen mit
plus d'un appareil de chauffage mehreren Feuerstätten
This European Standard was approved by CEN on 24 January 2015 and includes Amendment 1 approved by CEN on 27 April
2019.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13384-2:2015+A1:2019 E
worldwide for CEN national Members.
Contents Page
European foreword . 5
Introduction . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 General symbols and abbreviations . 10
5 Calculation method . 10
5.1 General principles . 10
5.2 Pressure equilibrium condition . 12
5.2.1 Negative pressure chimneys . 12
5.2.2 Positive pressure chimneys. 13
5.3 Mass flow requirement . 14
5.4 Pressure requirements . 14
5.4.1 Negative pressure chimneys . 14
5.4.2 Positive pressure chimneys. 15
5.5 Temperature requirement . 16
5.6 Calculation procedure . 17
6 Flue gas data characterising the !combustion" appliance . 19
7 Data for chimney and connecting flue pipes . 21
8 Basic data for the calculation . 21
8.1 General . 21
8.2 Air temperatures . 21
8.2.1 External air temperature (T ) . 21
L
8.2.2 Ambient air temperature (T ) . 21
u
8.3 External air pressure (p ) . 21
L
8.4 Gas constant . 21
8.4.1 Gas constant of the air (R ) . 21
L
8.4.2 Gas constant of flue gas (R) . 21
8.5 Density of air (ρ ) . 21
L
8.6 Specific heat capacity of the flue gas (c ) . 21
p
8.7 Water vapour content (σ(H O) ) and condensing temperature (T ) . 22
2 ,j sp
8.8 Correction factor for temperature instability (S ) . 22
H
8.9 Flow safety coefficient (S ) . 22
E
8.10 External coefficient of heat transfer . 22
9 Determination of temperatures. 22
10 Mixing calculations . 24
10.1 General . 24
10.2 Flue gas mass flow ( m ) . 24
,j
10.3 Flue gas temperature at the inlet of the chimney segment (T ) . 24
e,j
10.4 CO -content of the flue gas in the chimney segment (σ(CO ) ) . 25
2 2 ,j
10.5 H O-content of the flue gas (σ(H O) ) . 25
2 2 ,j
10.6 Gas constant of the flue gas (R ) . 25
,j
10.7 Flue gas data . 25
10.7.1 Specific heat capacity (c ), (c ) . 25
pV,j p,j
10.7.2 Thermal conductivity of the flue gas (λ ), (λ ) . 26
AV,j A,j
10.7.3 Dynamic viscosity (η ), (η ) . 26
AV,j A,j
10.7.4 Condensing temperature (T ) . 27
SP
11 Density and velocity of the flue gas . 27
12 Determination of the pressures . 28
12.1 Pressures at each inlet of the chimney segments . 28
12.1.1 Draught . 28
12.1.2 Positive pressure . 28
12.1.3 Draught due to chimney effect in the chimney segment (P ) . 28
H,j
12.1.4 Pressure resistance in the chimney segment (P ). 28
R,j
12.2 Minimum draught required at the flue gas inlet into the chimney and maximum
allowed draught (P and P ) and maximum and minimum differential pressure
Ze Zemax
at the flue gas inlet into the chimney (PZOe and PZOemin) . 31
12.2.1 Minimum required and maximum allowed draught . 31
12.2.2 Maximum available and minimum allowed differential pressure . 31
12.2.3 Calculated pressure resistance of the connecting flue pipe (P ) . 31
V,j
12.2.4 Calculated pressure resistance of the air supply (P ) . 33
Bc,j
13 Inner wall temperature . 34
14 Cascade installations . 35
14.1 Principle of the calculation method . 35
14.2 Pressure equilibrium condition . 35
14.2.1 Negative pressure cascade installation . 35
14.2.2 Positive pressure cascade installation . 36
14.3 Mass flow requirement . 37
14.4 Pressure requirements . 37
14.4.1 Negative pressure chimneys . 37
14.4.2 Positive pressure chimneys . 38
14.5 Temperature requirement . 39
14.6 Calculation procedure . 39
14.7 Pressures at the outlet of the connecting flue pipe and pressures at the inlet of the
collector segment . 40
14.7.1 Pressure at the flue gas inlet into the collector segment (P or P ) . 40
ZC,j,l ZOC,j,l
14.7.2 Pressures required or available at the outlet of the connecting flue pipe (P ,
ZeC,j,l
P ) . 43
ZOeC,j,l
14.8 Inner wall temperature (T ) . 45
iobC,j,l
15 Balanced flue chimney . 45
15.1 Principle of the calculation method . 45
15.2 Pressure equilibrium condition . 46
15.3 Mass flow requirement . 46
15.4 Pressure requirements . 46
15.4.1 Negative pressure chimneys . 46
15.4.2 Positive pressure chimneys . 47
15.5 Temperature requirements . 48
15.6 Calculation procedure for balanced flue chimneys . 48
15.7 Mass flow of the !combustion" air. 50
15.8 Determination of the temperatures in balanced flue chimneys . 51
15.8.1 Separate ducts . 51
15.8.2 Concentric ducts . 51
15.8.3 Concentric connection pipes . 59
15.9 Pressures of the air supply ducts . 65
15.9.1 Draught due to chimney effect of the air supply duct of chimney segment j . 65
15.9.2 Draught due to chimney effect of the air supply duct of connection pipes . 65
15.9.3 Pressure resistance of the air supply duct of the chimney segment j (P ) . 66
RB,j
15.9.4 Pressure resistance of the air supply duct of the connection pipe j (P ) . 67
RBV,j
15.10 Density and velocity of the !combustion" air . 69
15.10.1 Density and velocity of the !combustion" air in the air supply duct
averaged over the length of the chimney segment . 69
15.10.2 Density and velocity of the !combustion" air averaged over the length of
the connection pipes . 70
16 Consideration of chimney fans . 70
16.1 General . 70
16.2 Inline fans . 71
16.3 Exhaust fans . 72
Annex A (informative) Recommendations . 74
A.1 General . 74
A.2 Recommendations for the chimney and !combustion" appliances . 74
A.3 Recommendations for connecting flue pipes . 74
Annex B (informative) Characteristics for the !combustion" appliance . 75
European foreword
This document (EN 13384-2:2015+A1:2019) has been prepared by Technical Committee CEN/TC 166
“Chimneys”, the secretariat of which is held by ASI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by January 2020, and conflicting national standards shall
be withdrawn at the latest by January 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes !EN 13384-2:2015".
This document includes Amendment 1 approved by CEN on 26 June 2019.
According to EN 13384-2:2003+A1:2009 and EN 13384-2:2015+A1:2019 the following fundamental
changes are given:
— editorial mistakes have been corrected;
— mistakes in formulas have been corrected;
— characteristic values for !combustion" appliances for solid fuel and for liquid fuels in Annex B
have been adapted to actual data;
— for the mixture of fuels a clarification about the rise of the dew point has been added;
— for non-concentric ducts the calculation of the mean temperature of the air supply has been
amended;
— the process for iteration for appliances with low impact of the pressure to the flue gas mass flow
(e.g. CHP with combustion engine) has been simplified;
— for chimney fans a calculation procedure has been added;
— “heating appliance” replaced by “combustion appliance”;
— “Supply air” replaced by “combustion air”;
— New table for specification for gas-fired heating boilers Type C .
(10)
This standard is one of a series of standards prepared by CEN/TC 166 comprising product standards
and execution standards for chimneys.
National installation rules are not regarded in the standard.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association.
The start and finish of text introduced or altered by amendment is indicated in the text by tags !".
This European Standard “Chimneys — Thermal and fluid dynamic calculation methods” consists of
three Parts:
— Part 1: Chimneys serving one combustion appliance
— Part 2: Chimneys serving more than one combustion appliance
— Part 3: Methods for the development of diagrams and tables for chimneys serving one heating
appliance
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Introduction
The calculation described in this standard is complex and is intended to be solved by using a computer
programme. The general principles of this calculation method of EN 13384-1 also apply to this
standard.
This standard is in support of the execution standards for a chimney installation serving more than one
!combustion"appliance.
The execution standard identifies limitations and safety considerations associated with the design,
installation, commissioning and maintenance of a chimney serving more than one
!combustion"appliance (not dealt within the calculation method).
1 Scope
This part of EN 13384 specifies methods for calculation of the thermal and fluid dynamic characteristics
of chimneys serving more than one !combustion" appliance.
This part of EN 13384 covers both the cases, either
a) where the chimney is connected with more than one connecting flue pipe from individual or several
appliances in a multi-inlet arrangement; or
b) where the chimney is connected with an individual connecting flue pipe connecting more than one
appliance in a cascade arrangement.
The case of multiple inlet cascade arrangement is covered by the case a).
This part of EN 13384 deals with chimneys operating under negative pressure conditions (there can be
positive pressure condition in the connecting flue pipe) and with chimneys operating under positive
pressure conditions and is valid for chimneys serving !combustion" appliances for liquid, gaseous
and solid fuels.
This part of EN 13384 does not apply to:
— chimneys with different thermal resistance or different cross-section in the various chimney
segments. This part does not apply to calculate energy gain;
— chimneys with open fire places, e.g. open fire chimneys or chimney inlets which are normally
intended to operate open to the room;
— chimneys which serve different kinds of !combustion" appliances regarding natural draught,
fan assisted, forced draught or combustion engine. Fan assisted appliances with draught diverter
between the fan and the chimney are considered as natural draught appliances;
— chimneys with multiple inlets from more than 5 storeys. (This does not apply to balanced flue
chimney.);
— chimneys serving !combustion" appliances with open air supply through ventilation openings
or air ducts, which are not installed in the same air supply pressure region (e.g. same side of
building).
For positive pressure chimneys this part only applies if any !combustion" appliance which is out
of action can be positively isolated to prevent flue gas back flow.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN 1443:2003, Chimneys - General requirements
EN 13384-1:2015+A1:2019+A1:2019, Chimneys - Thermal and fluid dynamic calculation methods - Part
1: Chimneys serving one appliance
EN 15287-1:2007+A1:2010, Chimneys - Design, installation and commissioning of chimneys - Part 1:
Chimneys for non-roomsealed heating appliances
EN 15287-2:2008, Chimneys - Design, installation and commissioning of chimneys - Part 2: Chimneys for
roomsealed appliances
prEN 16475-2, Chimneys - Accessories - Part 2: Chimney fans - Requirements and test methods
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1443:2003, EN 13384-
1:2015+A1:2019+A1:2019, EN 15287-1:2007+A1:2010, EN 15287-2:2008 and the following apply.
3.1
chimney segment
part of a chimney between two consecutive flue gas connections or between the last flue gas connection
and the chimney outlet
3.2
collector segment
part of a connecting flue pipe between two consecutive flue gas connections or between the last flue gas
connection and the chimney inlet
3.3
flue gas mass flow
m
mass of the flue gas leaving the !combustion" appliance through the connecting flue pipe per unit
of time
Note 1 to entry: In case of a chimney serving more than one !combustion" appliance, the air being
transported through an appliance which is out of action is also given the term flue gas mass flow.
3.3.1
declared flue gas mass flow
m
W,j
flue gas mass flow given by the manufacturer of the !combustion" appliance j with respect to the
heat output used in the calculation
3.3.2
calculated flue gas mass flow
m
Wc,j
flue gas mass flow calculated with respect to calculated draught and the working conditions of the
!combustion" appliance j
3.4
calculated flue gas temperature
T
Wc,j
flue gas temperature at the outlet of the !combustion" appliance j depending on the calculated flue
gas mass flow
3.5
calculated draught of the flue gas of the !combustion" appliance
P
Wc,j
draught at the flue gas outlet of the !combustion" appliance j depending on the calculated flue gas
mass flow
3.6
flue damper
device to close or partially close the flue
3.7
balanced flue chimney
chimney where the point of air entry to the combustion air duct is adjacent to the point of discharge of
combustion products from the flue, the inlet and outlet being so positioned that wind effects are
substantially balanced
3.8
cascade arrangement
arrangement where two or more appliances situated in the same space are connected by a common
connecting flue pipe to the chimney
3.9
multi inlet arrangement
arrangement where two or more appliances are connected to the chimney by individual connecting flue
pipes
3.10
air duct
independent duct in a building or a structural part of a flue terminal conveying combustion air to a
room-sealed appliance
3.11
pressure equalizing opening
opening or duct that directly connects the air duct with the flue at its base
4 General symbols and abbreviations
Symbols, terminology and units are given to make the text of this standard understandable. A list of
general symbols and abbreviations is given in EN 13384-1 Indices added to symbols for purposes of the
calculation method for chimneys serving more than one !combustion" appliance relate to one
chimney segment and/or connection flue pipe section. An example of an indices numbering scheme is
given in Figures 1 and 2. Indices numbering shall begin at the lowest, farthest appliance connection. For
more than one cascade system/connection, the indices numbering scheme for the calculation formula
should be adopted in a similar manner to that for a single cascade scheme. Symbols assigned to a
specific section will be indicated by the number of the section after the comma (e. g. H is the effective
,1
height of a section of a chimney segment between the outlet of the connecting flue pipe of the
!combustion" appliance in the lowest position and the outlet of the connecting flue pipe of the
next !combustion" appliance).
Each symbol and abbreviation is explained at the formula where it is used.
5 Calculation method
5.1 General principles
The calculation is based upon determining the mass flow distribution in the chimney which fulfils the
pressure equilibrium condition (Formula (1)) at each flue gas inlet to the chimney (see Figure 1). After
such a distribution has been found four requirements shall be verified:
a) the mass flow requirement (Formulas (4) and (5))
b) the pressure requirement for minimum draught or maximum positive pressure (Formulas (6) or
(6b) and (6c))
c) the pressure requirement for maximum draught or minimum positive pressure (Formulas (6a) or
(6d))
d) the temperature requirement (Formula (7))
NOTE 1 The calculation is affected by the specific installation design. For recommendations for the installation
of appliance and connection flue pipes see Annex A.
NOTE 2 The pressure requirements for maximum draught or minimum positive pressure are only required if
there is a limit for the maximum draught for the (negative pressure) !combustion" appliance or a minimum
differential pressure of the (positive pressure) !combustion" appliance.
In order to verify the criteria two sets of external conditions are used:
— the calculation of the minimum draught and maximum positive pressure (draught) is made with
conditions for which the capacity of the chimney is minimal (i.e. high outside temperature); and
also
— the calculation of the maximum draught and minimum positive pressure and of the inner wall
temperature with conditions for which the inside temperature of the chimney is minimal (i.e. low
outside temperature).
The validation of the mass flow requirement and pressure requirement shall be done at following
working conditions, using the external and ambient air temperatures specified in EN 13384-1.
— All !combustion" appliances are simultaneously operating at nominal heat output.
— All !combustion" appliances are simultaneously operating at minimum heat output
— A single !combustion" appliance operating at nominal heat output and all other appliances
out of action (all possible cases)
— A single !combustion" appliance operating at minimum heat output and all other appliances
out of action (all possible cases)
!— For positive pressure chimneys a single !combustion" appliance operating at minimum
nominal heat output and all other appliances operating at maximum nominal heat output (all
possible cases) "
If the control of the installation guarantees that not all appliances will be in operation simultaneously,
the validation of the mass flow requirement and pressure requirement may be done with the maximum
number of appliances which will be in operation under the most adverse condition.
The validation for the mass flow requirement and pressure requirement for working conditions with
!combustion" appliances at minimum heat output is not required in the following cases:
— the !combustion" appliances do not have any heat output range
— the !combustion" appliances have a heat output which is limited to a fixed value as specified
on a label on the appliance. In this case the nominal heat output is the given heat output on the
label.
— !combustion" appliances heated with solid fuels without fan and appliances with regulated
air supply.
The validation of the mass flow requirement for working conditions with appliances at nominal heat
output is not required in the following case:
— the !combustion" appliances have a flue gas mass flow at minimum heat output higher than
or equal to the flue gas mass flow at nominal heat output.
The temperature requirement shall be validated for the following relevant working condition, using the
ambient and external air temperatures as specified in EN 13384-1:
— !combustion" appliances for solid fuels without fan and !combustion" appliances with
regulated air supply are in operation at nominal heat output,
— !combustion" appliances with a draught diverter which provide domestic hot water only are
out of action. These !combustion" appliances operate with a considerable secondary air
(These operate only a short time and therefore it can be assumed that condensation will not cause
damage or a lack in safety);
— !combustion" appliances with a fixed output range are in operation at this (nominal) heat
output;
— all other !combustion" appliances are in operation at minimum heat output.
When chimneys suitable for operating under wet conditions are located inside a building the check of
the temperature requirement is necessary only for the top of the chimney.
The validation of the temperature requirement is not necessary when the chimney serves only domestic
gas fired water heaters with instantaneous production and domestic gas fired storage water heaters.
If the chimney system includes a draught regulator, the system is handled as a cascade system.
5.2 Pressure equilibrium condition
5.2.1 Negative pressure chimneys
The following formulas shall be fulfilled for each chimney segment j at all relevant working conditions:
P −≤P 0,1, in Pa (1)
Z, jjZe,
N
P =−P+ (P − P ) , in Pa (2)
Z, j L ∑ H,k R,k
k= j
P = P + P + P , in Pa (3)
Ze,j Wc,j V,j Bc,j
where
P draught at the flue gas inlet to the chimney segment j, in Pa
Z,j
P theoretical draught due to chimney effect in chimney segment k, in Pa
H,k
P pressure resistance of the chimney segment k, in Pa
R,k
P calculated draught of the !combustion" appliance, in Pa
Wc,j
P calculated pressure resistance of the connecting flue pipe of chimney segment j, in Pa
V,j
P calculated pressure resistance of the air supply for the !combustion" appliance j, in Pa
Bc,j
P required draught at the flue gas inlet to the chimney segment j, in Pa
Ze,j
P wind velocity pressure, in Pa
L
N number of !combustion" appliances
Key
1 chimney
2 connecting flue pipe j
3 !combustion" appliance j
4 connecting flue pipe 2
5 !combustion" appliance 2
6 connecting flue pipe 1
7 !combustion" appliance 1
8 chimney segment 1
9 chimney segment j
Figure 1 — Example of multiple inlet arrangement and numbering pressure values and
temperature values of a chimney serving more than one !combustion" appliance
5.2.2 Positive pressure chimneys
The following formulas shall be fulfilled for each chimney segment j at all relevant working conditions:
P − P ≤ 0,1, in Pa (3a)
ZOe, j ZO, j
N
P =P+−(PP ) , in Pa (3b)
∑
ZO,j L R,k H,k
k= j
P P− PP− , in Pa (3c)
ZOe, j WOc,j V,j Bc,j
where
P positive pressure at the flue gas inlet to the chimney segment j, in Pa
ZO,j
PH,k theoretical draught due to chimney effect in chimney segment k, in Pa
PR,k pressure resistance of the chimney segment k, in Pa
P calculated positive differential pressure of the !combustion" appliance j, in Pa
WOc,j
PV,j calculated pressure resistance of the connecting flue pipe of chimney segment j, in Pa
PBc,j calculated pressure resistance of the air supply for the !combustion" appliance j, in Pa
P maximum differential pressure at the flue gas inlet to the chimney segment j, in Pa
ZOe,j
P wind velocity pressure,
L
N number of !combustion" appliances
5.3 Mass flow requirement
Formulas (4) and/or (5) shall be verified for all relevant working conditions (see 5.6).
For each !combustion" appliance in operation at nominal or minimum heat output:
m ≥ m , in kg/s (4)
Wc,j W,j
and for each !combustion" appliance out of action:
m ≥ 0 , in kg/s (5)
Wc,j
where
calculated mass flow of the !combustion" appliance, in kg/s
m
Wc,j
declared mass flow of the !combustion" appliance, in kg/s
m
W,j
Where a damper is applied, flow resistance shall be taken as 0 unless additional data are available.
5.4 Pressure requirements
5.4.1 Negative pressure chimneys
For negative pressure chimneys it has to be additionally checked that the negative pressure (minimum
) is more than or equal to the negative pressure in the room where the
draught) in the chimney (PZ,j
!combustion" appliance is placed at calculated draught conditions for air supply. The check on this
pressure requirement shall be done using the same conditions as specified for the check on the mass
flow requirement (see 5.3 and 5.6). The following relations shall be verified:
P ≥ P , in Pa (6)
Z,j Bc,j
where
P draught at the inlet to the chimney segment j, in Pa
Z,j
P calculated pressure resistance of the air supply for the !combustion" appliance j, in Pa
Bc,j
If required it has to be additionally checked that the negative pressure (draught) in the chimney (P )
Zmax,j
is less than or equal to the maximum allowed draught (P ) caused by the !combustion"
Zemax,j
appliance. The Formula (6a) shall be verified for all relevant working conditions (see 5.6).
=
The check of this pressure requirement shall be done with a separate calculation using the newly
calculated flue mass flows that fulfil the pressure equilibrium conditions at an external air temperature
of T = 258,15 K (t = -15 °C, see EN 13384-1).
L L
N
P = (P − P ) ≤ P + P + P = P , in Pa (6a)
Zmax, j ∑ H,k R,k Wmax,j V,j Bc,j Zemax,j
k= j
where
P maximum draught at the flue gas inlet into the chimney segment j, in Pa
Zmax,j
P maximum allowed draught at the flue gas inlet into the chimney segment j, in Pa
Zemax,j
PH,k theoretical draught due to chimney effect in chimney segment k, in Pa
P pressure resistance of the chimney segment k, in Pa
R,k
P maximum draught for the !combustion" appliance j, in Pa
Wmax,j
P calculated pressure resistance of the connecting flue pipe of chimney segment j, in Pa
V,j
P calculated pressure resistance of the air supply for the !combustion" appliance j, in
Bc,j
Pa
NOTE The values of PH,k, PR,k, PV,j and PBc,j in Formulas (2) and (6a) are normally different because the
conditions are different.
5.4.2 Positive pressure chimneys
For positive pressure chimneys it has to be additionally checked that the maximum positive pressure in
the connecting flue pipe (P + P ) and in the chimney (P ) is not higher than the excess pressure for
ZO,j V,j ZO,j
which both are designated (P and P ). The check on the pressure requirement shall be done
ZV excess Z excess
using the same conditions as specified for the check on the mass flow requirement (see 5.3 and 5.6).
The following relations shall be verified:
P ≤ P , in Pa (6b)
ZO,j Z excess
P + P ≤ P , in Pa (6c)
ZO,j V,j ZV excess
where
P positive pressure at the flue gas inlet to the chimney segment j, in Pa
ZO,j
P calculated pressure resistance of the connecting flue pipe of chimney segment j, in Pa
V,j
P is the maximum allowed pressure from the designation of the chimney, in Pa
Z excess
P is the maximum allowed pressure from the designation of the connecting flue pipe, in Pa
ZV excess
If required it has to be additionally checked that the minimum positive pressure in the chimney (P )
ZOmin,j
is more than or equal to the minimum allowed positive pressure (P ) caused by the
ZOemin,j
!combustion" appliance. The relation (6d) shall be verified for all relevant working conditions
(see 5.6).
The check of this pressure requirement shall be done with a separate calculation using the newly
calculated flue mass flows that fulfil the pressure equilibrium conditions at an external air temperature
of
T = 258,15 K (t = -15 °C, see EN 13384-1).
L L
N
P = (P − P ) ≥ P − P − P = P , in Pa (6d)
ZOmin,j R,k H,k WO min,j Bc,j V,j ZOe min,j
∑
k= j
where
P minimum positive pressure at the flue gas inlet into the chimney segment j, in Pa
ZOmin,j
P minimum differential pressure at the flue gas inlet into the chimney segment j, in Pa
ZOemin,j
P theoretical draught due to chimney effect in chimney segment k, in Pa
H,k
P pressure resistance of the chimney segment k, in Pa
R,k
P minimum differential pressure of the !combustion" appliance j, in Pa
WOmin,j
PBc,j calculated pressure resistance of the air supply for the !combustion" appliance j, in Pa
P calculated pressure resistance of the connecting flue pipe of chimney segment j, in Pa
V,j
NOTE The values of P and P in Formulas (3b) and (6d) are normally different because the conditions are
H,k R,k
different.
5.5 Temperature requirement
The relation (7) shall be verified for all relevant working conditions (see 5.6).
The check of the temperature requirement shall be done with a separate calculation using the newly
calculated flue mass flows that fulfil the pressure equilibrium conditions at an external air temperature
of T (see EN 13384-1)
o,j
u
T ≥ T , in K (7)
iob,j g,j
where
T temperature of the inner wall of the chimney segment j at the end, in K
iob,j
T temperature limit for chimney segment j, in K
g,j
The temperature limit T for chimneys suitable for operating under dry conditions is equal to the
g,j
condensing temperature T of the flue gas (see 8.6). T = T
sp,j g,j sp,j
The temperature limit T for chimneys suitable for operating under wet conditions is equal to the
g,j
freezing point of water: T = 273,15 K.
g,j
NOTE The following cases can be exempted from meeting the temperature requirement provided that it is
accepted that in case the requirement for temperature should be not fulfilled no guarantee can be given that no
moisture appears. In this cases insulation is advised.
— !combustion" appliances which are substituted to a usual chimney which is already in
operation and
— the heat output of the !combustion" appliances which are connected and/or substituted does
not exceed 30 kW for each and
— the flue gas losses are not more or equal than 8 % and
— an effective air conditioning of the chimney during standstill periods is given by draught diverters
or dampers and
...
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