
BS EN 674:2011
Current
The latest, up-to-date edition.

Glass in building. Determination of thermal transmittance (U value). Guarded hot plate method
Hardcopy , PDF
English
31-07-2011
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Basic formula
5 Brief outline of the measuring procedure
6 Test apparatus
7 Dimensions of the specimens
8 Preparation of the specimens
9 Performance of the measurements
10 Evaluation of the results
11 Expression of the results
12 Test report
Bibliography
Describes a measurement method to determine the thermal transmittance of glazing with flat and parallel surfaces. Structured surfaces, e.g. patterned glass, can be considered to be flat.
Committee |
B/520
|
DevelopmentNote |
Supersedes 92/12541 DC (08/2005)
|
DocumentType |
Standard
|
Pages |
16
|
PublisherName |
British Standards Institution
|
Status |
Current
|
Supersedes |
This European Standard specifies a measurement method to determine the thermal transmittance of glazing with flat and parallel surfaces. Structured surfaces, e.g. patterned glass, can be considered to be flat.
This European Standard applies to multiple glazing with outer panes which are not transparent to far infrared radiation, which is the case for soda lime silicate glass products, borosilicate glass and glass ceramics. Internal elements may be 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 an insulating glass unit or through the window frame are not included. Furthermore energy transfer due to solar radiation is not taken into account.
The procedure specified in this European Standard should generally only be considered when the calculation method detailed in EN 673 is inappropriate or unsuitable.
The document for the calculation of the overall U value of windows, doors and shutters (see [3]) gives normative reference to the U value evaluated for the glazing components according to this standard.
A vertical position of the glazing is specified.
U values evaluated according to the present standard are used for product comparison as well as for other purposes, in particular for predicting:
heat loss through glazing;
conduction heat gains in summer;
condensation on glazing surfaces;
the effects of the absorbed solar radiation in determining the solar factor (see [1]).
Reference should be made to [4], [5], or other European Standards dealing with heat loss calculations for the application of glazing U values determined by this standard.
The determination of the thermal transmittance is performed for conditions which correspond to the average situation for glazing in practice.
Standards | Relationship |
UNE-EN 674:1998 | Identical |
NF EN 674 : 2011 | Identical |
EN 674:2011 | Identical |
I.S. EN 674:2011 | Identical |
NBN EN 674 : 2011 | Identical |
NS EN 674 : 2011 | Identical |
SN EN 674 : 2011 | Identical |
NEN EN 674 : 2011 | Identical |
UNI EN 674 : 2011 | Identical |
ISO 10211:2017 | Thermal bridges in building construction — Heat flows and surface temperatures — Detailed calculations |
EN 673:2011 | Glass in building - Determination of thermal transmittance (U value) - Calculation method |
EN 410:2011 | Glass in building - Determination of luminous and solar characteristics of glazing |
EN 12898:2001 | Glass in building - Determination of the emissivity |
EN ISO 13790:2008 | Energy performance of buildings - Calculation of energy use for space heating and cooling (ISO 13790:2008) |
ISO 8302:1991 | Thermal insulation — Determination of steady-state thermal resistance and related properties — Guarded hot plate apparatus |
EN ISO 10211:2017 | Thermal bridges in building construction - Heat flows and surface temperatures - Detailed calculations (ISO 10211:2017) |
ISO 10077-1:2017 | Thermal performance of windows, doors and shutters — Calculation of thermal transmittance — Part 1: General |
ISO 13790:2008 | Energy performance of buildings Calculation of energy use for space heating and cooling |
EN ISO 10077-1:2017 | Thermal performance of windows, doors and shutters - Calculation of thermal transmittance - Part 1: General (ISO 10077-1:2017, Corrected version 2020-02) |
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