SIST EN ISO 14438:2004
(Main)Glass in building - Determination of energy balance value - Calculation method (ISO 14438:2002)
Glass in building - Determination of energy balance value - Calculation method (ISO 14438:2002)
This European Standard specifies a calculation method to determine the energy balance value of glazing. This
European Standard applies to transparent materials such as glass and combinations of glass used to glaze
windows in buildings.
This method is intended to evaluate the balance of heat loss and useful heat gain by solar radiation entering the
building through the glazing for a given period by means of an average rate of loss (or gain) of heat called the
energy balance value.
The method enables producers to compare the performance of their glazing products. The energy balance value
should not be used for energy use or heating capacity calculations in buildings.
Glas im Bauwesen - Bestimmung des Energiebilanz-Wertes - Berechnungsverfahren (ISO 14438:2002)
Diese Europäische Norm legt ein Berechnungsverfahren zur Bestimmung des Energiebilanzwertes von Verglasungen fest. Die vorliegende Europäische Norm gilt für lichtdurchlässige Materialien, wie Glas und Kombinationen aus Glas, die für Verglasungen von Fenstern in Gebäuden angewendet werden.
Dieses Verfahren dient der Bewertung der Bilanz von Wärmeverlust und nützlichen Wärmegewinnen durch die Sonnenstrahlung, die durch die Verglasung für einen festgelegten Zeitraum in das Gebäude eintritt, mit Hilfe einer mittleren Verlust-(oder Gewinn-)Rate, die Energiebilanzwert genannt wird.
Hersteller können mit diesem Verfahren die Gebrauchstauglichkeit ihrer Verglasungsprodukte vergleichen. Der Energiebilanzwert sollte nicht für Wärmeausnutzungs- oder Wärmekapazitätsberechnungen in Gebäuden verwendet werden.
Verre dans la construction - Détermination de la valeur du bilan énergétique - Méthode de calcul (ISO 14438:2002)
La présente Norme européenne spécifie une méthode de calcul servant à déterminer la valeur du bilan énergétique des vitrages. Elle s'applique aux matériaux transparents comme le verre ainsi qu'aux combinaisons de verres utilisées pour les vitres des bâtiments.
La présente méthode est destinée à évaluer, à partir de la différence entre la quantité utile de rayonnement solaire pénétrant dans un bâtiment par les vitrages et les déperditions de chaleur correspondantes pour une période de temps donnée, la déperdition thermique moyenne (ou le gain thermique moyen) qu'on appelle ici la valeur du bilan énergétique.
Elle permet aux producteurs de comparer les performances de leurs produits verriers. La valeur du bilan énergétique ne doit pas être utilisée pour les calculs de consommation d'énergie ou de capacité de chauffage des bâtiments.
Steklo v stavbah - Določanje vrednosti energijske bilance – Računska metoda (ISO 14438:2002)
General Information
- Status
- Published
- Publication Date
- 31-Aug-2004
- Technical Committee
- STV - Steklo, svetloba in razsvetljava v gradbeništvu
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 01-Sep-2004
- Due Date
- 01-Sep-2004
- Completion Date
- 01-Sep-2004
- Directive
- 89/106/EEC - Construction products
Overview
SIST EN ISO 14438:2004 is a European Standard developed by CEN that specifies a calculation method for determining the energy balance value of glazing used in building windows. This standard applies to transparent materials such as glass and glass combinations installed as window glazing in buildings. The method evaluates the balance between heat loss through the glazing and useful solar heat gain over a specified period, expressed as an average rate called the energy balance value, measured in W/(m²·K).
This calculation method is intended to assist manufacturers and designers in comparing the thermal performance of glazing products, focusing on their overall energy balance rather than precise heating or energy use calculations. It provides a standardized approach for assessing glazing performance related to solar radiation and thermal transmittance.
Key Topics
- Energy Balance Value (E): Represents the net effect of heat loss due to thermal transmittance minus solar heat gain from solar radiation through the glazing. It is calculated via a specific formula considering U-value, solar transmittance, solar radiation, utility factor, and maintenance factors.
- U Value (Thermal Transmittance): Measured per EN 673, 674, or 675, this value quantifies the rate of heat transfer through glazing per unit area and temperature difference.
- Solar Energy Transmittance (g-value): Defined by EN 410, this factor reflects the portion of solar radiation transmitted through glass, including direct transmission and absorbed/ re-radiated heat.
- Utility Factor (η): A parameter representing the effective use of solar heat gain in displacing heating loads within a building, generally ranging from 0.4 to 0.8. For comparative purposes, a standard value of 0.6 is used.
- Glazing Maintenance and Shadow Factor (f): Accounts for dirt accumulation and shading effects on glazing performance. A default value of 0.8 is applied for vertical or near-vertical surfaces.
- Solar Radiation Incident (Hₚ): The unobstructed solar radiation impacting a vertical glazing surface during the evaluation period, expressed in kWh/m².
- Degree Days (Dₚ): A temperature index representing heating demand over the period based on temperature difference from a specified base temperature (18°C used by default).
Applications
- Product Performance Comparison: Enables glazing manufacturers to benchmark the thermal performance and energy balance of different glazing products under standardized conditions.
- Building Design: Facilitates informed decision-making in selecting glazing systems that optimize the balance between heat retention and solar heat gain, enhancing building energy efficiency.
- Energy Assessment: Supports architects and engineers in evaluating glazing options to balance thermal comfort with energy savings during heating seasons.
- Climate Region Adaptation: The method incorporates climatic data (solar radiation and degree days) for different locations to tailor glazing evaluations regionally.
- Regulatory and Quality Standards Compliance: Assists in meeting CEN and ISO requirements for glazing energy performance ratings.
Related Standards
- EN 410: Glass in Building - Determination of luminous and solar characteristics of glazing, essential for determining the solar transmittance (g-value).
- EN 673: Glass in Building - Determination of thermal transmittance (U-value) - Calculation method, used to calculate the heat transfer rate through glazing.
- EN 674 and EN 675: Methods for measuring the thermal transmittance of glazing using guarded hot plate and heat flow meter methods, respectively.
- EN 832: Thermal performance of buildings - Calculation of energy use for heating - Residential buildings, relevant for determining the utility factor η based on heating needs.
SIST EN ISO 14438:2004 provides a practical and consistent framework for evaluating glazing products' energy performance with a focus on balancing thermal losses and solar gains. This standard is essential for glazing producers, building designers, and energy assessors aiming to enhance building envelope performance and contribute to energy-efficient construction.
Frequently Asked Questions
SIST EN ISO 14438:2004 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Glass in building - Determination of energy balance value - Calculation method (ISO 14438:2002)". This standard covers: This European Standard specifies a calculation method to determine the energy balance value of glazing. This European Standard applies to transparent materials such as glass and combinations of glass used to glaze windows in buildings. This method is intended to evaluate the balance of heat loss and useful heat gain by solar radiation entering the building through the glazing for a given period by means of an average rate of loss (or gain) of heat called the energy balance value. The method enables producers to compare the performance of their glazing products. The energy balance value should not be used for energy use or heating capacity calculations in buildings.
This European Standard specifies a calculation method to determine the energy balance value of glazing. This European Standard applies to transparent materials such as glass and combinations of glass used to glaze windows in buildings. This method is intended to evaluate the balance of heat loss and useful heat gain by solar radiation entering the building through the glazing for a given period by means of an average rate of loss (or gain) of heat called the energy balance value. The method enables producers to compare the performance of their glazing products. The energy balance value should not be used for energy use or heating capacity calculations in buildings.
SIST EN ISO 14438:2004 is classified under the following ICS (International Classification for Standards) categories: 81.040.20 - Glass in building. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN ISO 14438:2004 is associated with the following European legislation: EU Directives/Regulations: 305/2011, 89/106/EEC. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
SIST EN ISO 14438:2004 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-september-2004
6WHNORYVWDYEDK'RORþDQMHYUHGQRVWLHQHUJLMVNHELODQFH±5DþXQVNDPHWRGD ,62
Glass in building - Determination of energy balance value - Calculation method (ISO
14438:2002)
Glas im Bauwesen - Bestimmung des Energiebilanz-Wertes - Berechnungsverfahren
(ISO 14438:2002)
Verre dans la construction - Détermination de la valeur du bilan énergétique - Méthode
de calcul (ISO 14438:2002)
Ta slovenski standard je istoveten z: EN ISO 14438:2002
ICS:
81.040.20 Steklo v gradbeništvu Glass in building
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN ISO 14438
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2002
ICS 81.040.20
English version
Glass in building - Determination of energy balance value -
Calculation method (ISO 14438:2002)
Verre dans la construction - Détermination de la valeur du Glas im Bauwesen - Bestimmung des Energiebilanz-
bilan énergétique - Méthode de calcul (ISO 14438:2002) Wertes - Berechnungsverfahren (ISO 14438:2002)
This European Standard was approved by CEN on 5 March 2002.
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 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2002 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 14438:2002 E
worldwide for CEN national Members.
Contents
page
Foreword.3
1 Scope.4
2 Normative references .4
3 Symbols .4
4 Basic formula.5
5 Basic material properties.5
6 Solar radiation incident, H .6
p
7 Degree day data, D .6
p
8 Period of application, p .6
9 Principal values and presentation.6
10 Alternative simplification of principal values and presentation.7
Annex A (informative) Examples of climatic data p, Dp and Hp.8
Annex B (informative) Examples of calculation of the energy balance value .9
Bibliography .11
Foreword
This document (EN ISO 14438:2002) has been prepared by Technical Committee CEN/TC 129 "Glass in building",
the secretariat of which is held by IBN, in collaboration with Technical Committee ISO/TC 160 "Glass in building".
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 December 2002, and conflicting national standards shall be withdrawn at the latest
by December 2002.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard : Austria, Belgium, Czech Republic, Denmark, Finland,
France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain,
Sweden, Switzerland and the United Kingdom.
A first Formal Vote took place within CEN as prEN 14026 between 2000-10-19 and 2000-12-19.
Annexes A and B are informative.
This standard includes a Bibliography.
1 Scope
This European Standard specifies a calculation method to determine the energy balance value of glazing. This
European Standard applies to transparent materials such as glass and combinations of glass used to glaze
windows in buildings.
This method is intended to evaluate the balance of heat loss and useful heat gain by solar radiation entering the
building through the glazing for a given period by means of an average rate of loss (or gain) of heat called the
energy balance value.
The method enables producers to compare the performance of their glazing products. The energy balance value
should not be used for energy use or heating capacity calculations in buildings.
2 Normative references
This European Standard incorporates by dated or undated references, provisions from other publications. These
normative references are cited at the appropriate places in the text and the publications are listed hereafter. For
dated references, subsequent amendments to or revisions of any of these publications apply to this European
Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the
publication referred to applies (including amendments).
EN 410 Glass in building - Determination of luminous and solar characteristics of glazing
EN 673 Glass in building - Determination of thermal transmittance (U value) - Calculation method
EN 674 Glass in building - Determination of thermal transmittance (U value) - Guarded hot plate method
EN 675 Glass in building - Determination of thermal transmittance (U value) - Heat flow meter method
EN 832 Thermal performance of buildings - Calculation of energy use for heating - Residential buildings
3 Symbols
D degree days K·24 h
utility factor
H unobstructed incident solar radiation 2
kWh/m
g total solar energy transmittance (solar factor)
U U
thermal transmittance ( value) 2
W/(m ·K)
f factor due to glazing maintenance and shadow effects
S function of H and D characterising a given region 2
W/(m ·K)
E energy balance value 2
W/(m ·K)
Subscripts
p period of application
4 Basic formula
The energy balance value, E, for a given period is calculated according to the following equation:
g f H
p
E U
(1)
D
p
where:
U is the U value of the glazing;
is the utility factor;
f is the factor due to glazing maintenance and shadow effects
;
g is the glazing total solar energy transmittance (solar factor);
H is the unobstructed incident solar radiation during the given period;
p
D is the degree day total for the given period.
p
NOTE An example of calculation is given in annex B.
5 Basic material properties
5.1 U Value (thermal transmittance)
The U value of the glazing is determined by calculation, in accordance with EN 673 or measurement in accordance
with EN 674 or EN 675.
5.2 Utility factor,
The utility factor for a building or space in a building is the ratio of the useful heat gains, which displace the
functional heating over a defined period,
...
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