EN 673:2011
(Main)Glass in building - Determination of thermal transmittance (U value) - Calculation method
Glass in building - Determination of thermal transmittance (U value) - Calculation method
This European Standard specifies a calculation method to determine the thermal transmittance of glazing with flat and parallel surfaces.
This European Standard applies to uncoated glass (including glass with structured surfaces, e.g. patterned glass), coated glass and materials not transparent in the far infrared which is the case for soda lime glass products, borosilicate glass and glass ceramic. It applies also to multiple glazing comprising such glasses and/or materials. It does not apply to multiple glazing which include in the gas space sheets or foils that are far infrared transparent. The procedure specified in this European Standard determines the U value ) (thermal transmittance) in the central area of glazing.
The edge effects due to the thermal bridge through the spacer of a sealed glazing unit or through the window frame are not included. Furthermore, energy transfer due to solar radiation is not taken into account. The effects of Georgian and other bars are excluded from the scope of this European Standard.
The Standard for the calculation of the overall U value of windows, doors and shutters (see A.1) gives normative reference to the U value calculated for the glazing components according to this standard.
For the purpose of product comparison, a vertical position of the glazing is specified. In addition, U values are calculated using the same procedure for other purposes, in particular for predicting:
- heat loss through glazing;
- conduction heat gains in summer;
- condensation on glazing surfaces;
- the effect of the absorbed solar radiation in determining the solar factor (see Clause 2).
Reference should be made to [3], [4] and [5] or other European Standards dealing with heat loss calculations for the application of glazing U values determined by this standard.
A procedure for the determination of emissivity is given in EN 12898.
The rules have been made as simple as possible consistent with accuracy.
Glas im Bauwesen - Bestimmung des Wärmedurchgangskoeffizienten (U-Wert) - Berechnungsverfahren
Diese Europäische Norm enthält ein Berechnungsverfahren zur Bestimmung des Wärmedurchgangs-koeffizienten von Verglasungen mit ebenen und parallelen Oberflächen.
Die vorliegenden Europäische Norm gilt für unbeschichtetes Glas (einschließlich Glas mit strukturierter Oberfläche, z. B. Ornamentglas), beschichtetes Glas und für Materialien, die im fernen Infrarotbereich undurchlässig sind, z. B. Produkte aus Kalknatronglas, Borosilicatglas und Glaskeramik. Sie gilt ebenfalls für Mehrfachverglasungen aus derartigen Gläsern und/oder Materialien. Für Mehrfachverglasungen mit Schichten oder Folien im Gaszwischenraum, die im fernen Infrarotbereich durchlässig sind, gilt diese Norm nicht. Mit dem in dieser Europäischen Norm festgelegten Verfahren wird der U Wert ) (Wärme¬durchgangs¬koeffizient) im mittleren Bereich einer Verglasung bestimmt.
Die Randwirkungen infolge der Wärmebrücke durch den Abstandhalter einer hermetisch abgeschlossenen Verglasung oder durch den Fensterrahmen sind nicht berücksichtigt. Die Wärmeübertragung durch Sonneneinstrahlung wurde ebenfalls nicht berücksichtigt. Die von Sprossen und anderen Leisten/Riegeln ausgehenden Einwirkungen fallen nicht in den Anwendungsbereich dieser Europäischen Norm.
Der nach der vorliegenden Norm berechnete U Wert für Verglasungselemente ist bei der Berechnung des Gesamt U Werts von Fernster, Türen und anderen Abschlüssen (siehe EN ISO 10077 [1]) zu verwenden.
Zum Zweck des Vergleichs von Produkten ist eine senkrechte Lage der Verglasung festgelegt. Zusätzlich werden nach demselben Verfahren U Werte für weitere Zwecke berechnet, besonders für die Voraussage von:
- Wärmeverlusten durch Verglasungen;
- Erhöhungen der Wärmeleitung im Sommer;
- Tauwasserbildung auf Glasoberflächen;
- Auswirkungen der absorbierten Sonnenstrahlung auf die Bestimmung des Sonnenfaktors (siehe Literaturhinweis [2]).
(...)
Verre dans la construction - Détermination du coefficient de transmission thermique, U - Méthode de calcul
La présente Norme européenne spécifie une méthode de calcul du coefficient de transmission thermique des vitrages à surfaces planes et parallèles. Cette Norme européenne est applicable au verre sans couche (y compris le verre avec surfaces structurées, par exemple le verre imprimé), au verre recouvert d'une couche et aux matériaux opaques au rayonnement infrarouge lointain, ce qui est le cas pour les produits verriers sodo-calciques, le verre borosilicate et les vitrocéramiques. Elle est également applicable aux vitrages multiples qui comportent de tels verres et/ou matériaux. Elle n'est pas applicable aux vitrages multiples qui comportent dans la lame de gaz des panneaux ou feuilles transparents au rayonnement infrarouge de grande longueur d'onde. La procédure présentée dans cette Norme européenne détermine la valeur de U1Les effets de bord dus au pont thermique de l'intercalaire d'un vitrage isolant ou du châssis de fenêtre ne sont pas inclus. Par ailleurs, il n'est pas tenu compte du transfert d'énergie provenant du rayonnement solaire. Les effets des croisillons insérés et autres barres sont exclus du domaine d'application de la présente Norme européenne. ) (coefficient de transmission thermique) dans la zone centrale du vitrage. La norme qui permet le calcul du U global de fenêtres, portes et autres fermetures (voir EN ISO 10077-1 [1]) fait référence normative à la valeur de U obtenue selon cette norme pour les composants verriers. Pour faciliter la comparaison entre vitrages, ceux-ci sont considérés en position verticale. En outre, les valeurs de U sont calculées dans d'autres buts en utilisant la même procédure, en particulier pour la détermination des caractéristiques suivantes : - perte de chaleur au travers des vitrages ; - gains de chaleur par conduction en été ; - condensation sur les surfaces des vitrages ; - appréciation du rayonnement solaire absorbé dans la détermination du facteur solaire (voir Bibliographie [2]). (...)
Steklo v gradbeništvu - Določevanje toplotne prehodnosti (vrednost U) - Računska metoda
Ta evropski standard določa metodo izračuna za določevanje toplotne prehodnosti stekla s ploskimi in vzporednimi površinami.
Ta evropski standard velja za nepremazano steklo (vključno s steklom s strukturirano površino, npr. vzorčastim steklom), prevlečeno steklo in materiale, ki pri skrajni infrardeči svetlobi niso prozorni, kot velja za steklene proizvode iz mešanice natrijevega hidroksida in kalcijevega hidroksida, borosilikatno steklo in stekleno keramiko. Velja tudi za večkratno zasteklitev, ki zajema taka stekla in/ali materiale. Ne velja za večkratne zasteklitve, ki v plinskem prostoru vključujejo plošče ali folije, ki so prozorne v skrajni infrardeči svetlobi. S postopkom, ki ga opredeljuje ta evropski standard, se določa vrednost U (toplotno prehodnost) v osrednjem delu stekla.
Robni učinki zaradi toplotnega mostu med vmesnikom zatesnjene steklene enote ali skozi okvir okna niso vključeni. Tudi prenos energije zaradi sončnega sevanja ni upoštevan. Učinki georgijanskih in drugih prečk so izvzeti iz obsega tega evropskega standarda.
Standard za izračune skupne vrednosti U oken, vrat in rolet (glej točko A.1) podaja normativno referenco za vrednost U, izračunano za steklene komponente v skladu s tem standardom.
Za namen primerjave proizvodov je določen navpični položaj stekla. Poleg tega se vrednosti U izračunajo z istim postopkom tudi za druge namene, predvsem za napovedovanje:
- toplotne izgube prek stekla;
- prevodnega segrevanja poleti;
- kondenza na steklenih površinah;
- učinka absorbiranega sončnega sevanja pri določevanju sončnega dejavnika (glej klavzulo 2).
Za uporabo vrednosti U-stekla, določene s tem standardom, se je treba sklicevati na [3], [4] in [5] ali druge evropske standarde, ki obravnavajo izračune toplotnih izgub.
Postopek za določevanje oddajnosti je naveden v EN 12898.
Pravila so čim bolj poenostavljena, a še vedno natančna.
General Information
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Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.PHWRGDGlas im Bauwesen - Bestimmung des U-Wertes (Wärmedurchgangskoeffizient) - BerechnungsverfahrenVerre dans la construction - Détermination du coefficient de transmission thermique, U - Méthode de calculGlass in building - Determination of thermal transmittance (U value) - Calculation method81.040.20Steklo v gradbeništvuGlass in buildingICS:Ta slovenski standard je istoveten z:EN 673:2011SIST EN 673:2011en,fr,de01-maj-2011SIST EN 673:2011SLOVENSKI
STANDARDSIST EN 673:1999/A2:2004SIST EN 673:1999/A1:2001SIST EN 673:19991DGRPHãþD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 673
February 2011 ICS 81.040.20 Supersedes EN 673:1997English Version
Glass in building - Determination of thermal transmittance (U value) - Calculation method
Verre dans la construction - Détermination du coefficient de transmission thermique, U - Méthode de calcul
Glas im Bauwesen - Bestimmung des U-Werts (Wärmedurchgangskoeffizient) - Berechnungsverfahren This European Standard was approved by CEN on 2 January 2011.
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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 673:2011: ESIST EN 673:2011
Iteration procedure for glazing with more than one gas space . 16Bibliography . 18 SIST EN 673:2011
This European Standard specifies a calculation method to determine the thermal transmittance of glazing with flat and parallel surfaces. This European Standard applies to uncoated glass (including glass with structured surfaces, e.g. patterned glass), coated glass and materials not transparent in the far infrared which is the case for soda lime glass products, borosilicate glass and glass ceramic. It applies also to multiple glazing comprising such glasses and/or materials. It does not apply to multiple glazing which include in the gas space sheets or foils that are far infrared transparent. The procedure specified in this European Standard determines the U value1) (thermal transmittance) in the central area of glazing. The edge effects due to the thermal bridge through the spacer of a sealed glazing unit or through the window frame are not included. Furthermore, energy transfer due to solar radiation is not taken into account. The effects of Georgian and other bars are excluded from the scope of this European Standard. The standard for the calculation of the overall U value of windows, doors and shutters (see EN ISO 10077-1 [1]) gives normative reference to the U value calculated for the glazing components according to this standard. For the purpose of product comparison, a vertical position of the glazing is specified. In addition, U values are calculated using the same procedure for other purposes, in particular for predicting: heat loss through glazing; conduction heat gains in summer; condensation on glazing surfaces; the effect of the absorbed solar radiation in determining the solar factor (see Bibliography, [2]). Reference should be made to [3], [4] and [5] or other European Standards dealing with heat loss calculations for the application of glazing U values determined by this standard. A procedure for the determination of emissivity is given in EN 12898.
1) In some countries the symbol k has been used hitherto.
A
constant
-
c
specific heat capacity of gas
J/(kg⋅K)
d
thickness of material layer (glass
or alternative glazing material)
m
F
volume fraction
-
h
- heat transfer coefficient
W/(m2⋅K)
- also thermal conductance
W/(m2⋅K)
M
number of material layers
-
n
exponent
-
N
number of spaces
- SIST EN 673:2011
r
thermal resistivity of glass (glazing material)
m⋅K/W
P
gas property
-
s
width of gas space
m
T
absolute temperature
K
U
thermal transmittance
W/(m2⋅K)
∆Τ temperature difference
K
ε
corrected emissivity
-
εn
normal emissivity (perpendicular to the surface)
-
ρ
gas density
kg/m3
σ
Stefan-Boltzmann's constant 5,67 x 10-8
W/(m2⋅K4)
µ
dynamic viscosity of gas
kg/(m⋅s)
λ
- thermal conductivity of gas in space
W/(m⋅K)
ϑ
temperature on the Celsius scale
°C 4.2 Dimensionless Numbers
Gr
Grashof number
-
Nu
Nusselt number
-
Pr
Prandtl number
- 4.3 Subscripts
c
convection
e
external
i
internal
j
jth material layer
k
kth space
g
gas
m
mean
n
normal
r
radiation
s
space SIST EN 673:2011
t
total
1;2
first, second etc. 5 Basic formulae 5.1 General The method of this standard is based on a calculation according to the following principles. 5.2 U value The U value is given by: 1U=1he+1ht+1hi (1) where
he and hi are the external and internal heat transfer coefficients;
ht is the total thermal conductance of the glazing. 1ht=1hs1N∑+dj1M∑⋅rj (2) where
hs is the thermal conductance of each gas space;
N is the number of spaces;
dj is the thickness of each material layer;
rj is the thermal resistivity of each material (thermal resistivity of soda lime glass =
1,0 m⋅K/W);
M is the number of material layers. hs,k = hr,k + hg,k (3) where
hs,k
...
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