BRITISH STANDARDThermal performance of windows, doors and shutters Ð Calculation of thermal transmittance Ð Part 1: Simplified method The European Standard EN ISO 10077-1:2000 has the status of a British Standard ICS 91.060.50; 91.120.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW | BS EN ISO | | | 10077-1:2000 | | | Corrected and reprinted | | December 2001 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BS EN ISO 10077-1:2000 National foreword This British Standard is the official English language version of EN ISO 10077-1:2000. It is identical with EN ISO 10077-1:2000. The UK participation in its preparation was entrusted by Technical Committee B/540, Energy performance of materials, components and buildings, to Subcommittee B/540/1, European Standards for thermal insulation, which has the responsibility to: Ð aid enquirers to understand the text; Ð present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; Ð monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British Standards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entitled ªInternational Standards Correspondence Indexº, or by using the ªFindº facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN ISO title page, pages 2 to 31 and a back cover. The BSI copyright notice displayed in this document indicates when this document was updated. This British Standard, having been prepared under the direction of the Sector Committee for Building and Civil Engineering, was published under the authority of the Standards Committee and comes into effect on 15 September 2000 BSI 10 December 2001 ISBN 0 580 32641 1 Amendments issued since publication Amd. No. Date Comments EUROPEAN STANDARD EN ISO 10077-1 NORME EUROPÉENNE EUROPÄISCHE NORM July 2000 ICS 91.060.50; 91.120.10 English version Thermal performance of windows, doors and shutters Calculation of thermal transmittance - Part 1: Simplified method (ISO 10077-1:2000) Performance thermique des fenêtres, portes et fermetures Calcul du coefficient de transmission thermique - Partie 1: Méthode simplifiée (ISO 10077-1:2000) Wärmetechnisches Verhalten von Fenstern, Türen und Abschlüssen - Berechnung des Wärmedurchgangskoeffizienten - Teil 1: Vereinfachtes Verfahren (ISO 10077-1:2000) This European Standard was approved by CEN on 21 July 1999. 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 Central Secretariat 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 Central Secretariat 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, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG Central Secretariat: rue de Stassart, 36 © 2000 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. B-1050 Brussels Ref. No. EN ISO 10077-1:2000 E Page 2 EN ISO 10077-1:2000 Contents Page Foreword 3 Introduction 3 1 Scope 4 2 Normative references 5 3 Definitions. symbols and units 6 4 Geometrical characteristics 7 5 Calculation of thermal transmittance 9 6 Input data 15 7 Report 15 Annex A (normative) Internal and external surface thermal resistances 17 Annex B (informative) Thermal conductivity of glass 17 Annex C (informative) Thermal resistance of air spaces between glazing and thermal transmittance of coupled or double glazing 18 Annex D (informative) Thermal transmittance of frames 20 Annex E (informative) Linear thermal transmittance of frame/glazing junction 25 Annex F (informative) Thermal transmittance of windows 26 Annex G (informative) Additional thermal resistance for windows with closed shutters 28 Annex H (informative) Permeability of shutters 29 Annex ZA (informative) A-deviations 31 . Greece. Germany. Sweden. In some countries the calculation of the thermal transmittance of windows forms part of their national regulations.Page 3 EN ISO 10077-1:2000 Foreword The text of EN ISO 10077-1:2000 has been prepared by Technical Committee CEN/TC 89 "Thermal performance of buildings and building components". . Denmark. the secretariat of which is held by SIS . This European Standard shall be given the status of a national standard. An alternative to this calculation method is testing according to EN ISO 12567 “Thermal performance of windows and doors – Determination of thermal transmittance by hot box methods”. Czech Republic. see informative Annex ZA. either by publication of an identical text or by endorsement. Part 2 covers the numerical calculation (twodimensional) of the thermal transmittance of frame profiles. Information about national deviations from this standard due to regulations are given in annex ZA. in collaboration with Technical Committee ISO/TC 163 "Thermal insulation". Italy. This standard is one of a series of standards on calculation methods for the design and evaluation of the thermal performance of buildings and building components. Norway. Portugal. For relationship with EU Directive(s). the national standards organizations of the following countries are bound to implement this European Standard: Austria. Spain. France. Belgium. Netherlands. and conflicting national standards shall be withdrawn at the latest by January 2001. or as part of the determination of the energy use of a building. Iceland. Luxembourg. Switzerland and the United Kingdom. Finland. Introduction The method described in this standard is used to evaluate the thermal transmittance of windows and doors. at the latest by January 2001. It contains two parts. which is an integral part of this standard. According to the CEN/CENELEC Internal Regulations. Ireland. Part 1 deals with the simplified calculation of the thermal transmittance of windows and doors with or without shutters. where appropriate.various types of frames (wood. the additional thermal resistance introduced by different types of shutters. The calculation does not include: – – – – effects of solar radiation. Roof windows are also excluded because of their complex geometrical frame sections. with and without shutters. It allows for: . heat transfer caused by air leakage. Default values for glazings. . frames and shutters are given in the informative annexes. calculation of condensation. single or multiple glazing. plastic. Curtain walls and other structural glazings. depending on their air permeability. with or without low emissivity coatings.Page 4 EN ISO 10077-1:2000 1 Scope This standard specifies methods for the calculation of the thermal transmittance of windows and doors consisting of glazed or opaque panels fitted in a frame. . are excluded from this standard.different types of glazing (glass or plastics. metallic with and without thermal barrier. with spaces filled with air or other gases). which are not fitted in a frame. metallic with pinpoint metallic connections or any combination of materials). ventilation of air spaces in double and coupled windows. Thermal bridge effects at the rebate or joint between the window or door frame and the rest of the building envelope are excluded from the calculation. . provisions from other publications.Insulating glass units . For undated references the latest edition of the publications referred to applies.Insulating glass units .Part 2: Numerical method for frames (ISO/DIS 10077-2) Thermal bridges in building construction . EN 673 EN 674 EN 675 prEN 1098 prEN 1279-1 prEN 1279-3 prEN 12412-2 EN 12524 EN ISO 6946 EN ISO 7345 prEN ISO 10077-2 EN ISO 10211-2 ISO 8302 Glass in building – Determination of thermal transmittance (U value) – Calculation method Glass in building – Determination of thermal transmittance (U value) Guarded hot plate method Glass in building – Determination of thermal transmittance (U value) – Heat flow meter method Measuring method for the determination of the thermal transmittance of multiple glazing (U value) – Calibrated and guarded hot box method Glass in building .Determination of thermal transmittance by hot box method – Part 2: Frames Building materials and products – Hygrothermal properties – Tabulated design values Building components and building elements – Thermal resistance and thermal transmittance – Calculation method (ISO 6946) Thermal insulation – Physical quantities and definitions (ISO 7345) Thermal performance of windows. doors and shutters . subsequent amendments to or revisions of any of these publications apply to this standard only when incorporated in it by amendment or revision.Part 1: Generalities and dimensional tolerances Glass in building . gas leakage rate Windows. For dated references.Page 5 EN ISO 10077-1:2000 2 Normative references This standard incorporates by dated or undated reference.Part 3: Initial type testing on gas-filled insulating glass units. doors and shutters .Calculation of thermal transmittance . These normative references are cited at the appropriate places in the text and the publications are listed hereafter.Calculation of heat flows and surface temperatures .Part 2: Linear thermal bridges (ISO 10211-2) Thermal insulation – Determination of steady-state thermal resistance and related properties – Guarded hot plate apparatus . 1 Definitions For the purposes of this standard.3 Quantity area thermal resistance temperature thermal transmittance width distance / thickness length density of heat flow rate linear thermal transmittance thermal conductivity Unit m2 m2·K/W K W/(m2·K) m m m W/m2 W/(m·K) W/(m·K) Subscripts Ad. symbols and units 3. descriptions are given of a number of geometrical characteristics of glazing and frame. 3.Page 6 EN ISO 10077-1:2000 3 Definitions.Internal and external developed area D W WS d e f g i sa door window window with closed shutter developed external frame glazing internal sash j p s se sh si summation index panel (opaque) space (air or gas space) external surface shutter internal surface . the definitions given in EN 673 and EN ISO 7345 apply.i internal frame external Ad.e Figure 1 . In clause 4 of this standard.2 Symbols Symbol A R T U b d l q 3. If the perimeters are different on either side of the pane or panel then the larger of the two shall be used. Ad. Frame area Af The frame area is the larger of the two projected areas seen from both sides. 4.i Internal developed frame area The internal developed frame area is the area of the frame in contact with the internal air (see figure 1).Page 7 EN ISO 10077-1:2000 4 Geometrical characteristics 4. Internal projected frame area The internal projected frame area is the area of the projection of the internal frame on a plane parallel to the glazing panel. Af.e External projected frame area The external projected frame area is the area of the projection of the external frame on a plane parallel to the glazing panel. lg lg glass Ag Figure 2 . Af.3 Frame areas For the definition of the areas see also figure 3. Ad. see figure 2. Any overlapping of gaskets is ignored.Illustration of glazed area and perimeter 4.1 Glazed area.2 Total visible perimeter of the glazing The total perimeter of the glazing lg (or the opaque panel lp) is the sum of the visible perimeter of the glass panes (or opaque panels) in the window or door. opaque panel area The glazed area Ag or the opaque panel area Ap of a window or door is the smaller of the visible areas seen from both sides. see figure 2.e External developed frame area The external developed frame area is the area of the frame in contact with the external air (see figure 1).i . Af.i = A1 + A2 + A3 + A4 Ad.e Aw NOTE Af = max (Af.e) Aw = Af + Ag Ad.i = Af A1 Ag A3 A2 internal A4 sash (movable) frame (fixed) A8 A7 A5 A6 Af. Af.i .Illustration of the various areas external .e = A5 + A6 + A7 + A8 Figure 3 .4 Window area The window area Aw is the sum of the frame area Af and the glazing area Ag (or the panel area Ap).Page 8 EN ISO 10077-1:2000 4. 1 Windows 5. Uw is calculated as follows: UW Ag U g Ap U p Af U f lg g lp p Ag Ap Af (2) where is the thermal transmittance of the opaque panel(s). prEN 12412-2 gives a method for measuring the linear thermal transmittance. When opaque panels are used instead of some of the glazing. the effect of the bridging shall be taken into account in the same way as for glazing.Illustration of single window The thermal transmittance of a single window Uw shall be calculated using equation (1): UW Ag U g Af U f lg g Ag Af (1) where Ug is the thermal transmittance of the glazing. .1 Single windows frame (fixed) sash (movable) glazing (single or multiple) Figure 4 . and the other symbols are defined in clause 4. Up p is the linear thermal transmittance for the opaque panel(s). otherwise p = 0. Uf is the linear thermal transmittance due to the combined thermal effects of glazing. is the thermal transmittance of the frame. g spacer and frame.Page 9 EN ISO 10077-1:2000 5 Calculation of thermal transmittance 5. NOTE Typical values of the linear thermal transmittance are given in annex E. In the case of single glazing the last term of the numerator in equation (1) shall be taken as zero (no spacer effect) because any correction is negligible. prEN ISO 10077-2 gives a method for calculating linear thermal transmittance.1. If the opaque panel is thermally bridged at the edge by a less insulating spacer. 2 Double windows internal 1/Uw1 Rse 1/Uw frame (fixed) sash (movable) glazing (single or multiple) Rs Rsi 3 mm 1/Uw2 3 mm external Figure 5 . respectively. is the internal surface resistance of the external window when used alone. Typical values of Rsi and Rse are given in normative annex A and of Rs in the informative annex C. is the thermal resistance of the space between the glazing in the two windows. calculated according to equation (1). NOTE If the gap exceeds 3 mm and measures have not been taken to prevent excessive air exchange with external air.Page 10 EN ISO 10077-1:2000 5.1. .Illustration of double window The thermal transmittance UW of a system consisting of two separate windows shall be calculated by the following equation: UW 1 1 / U W1 Rsi Rs Rse 1 / U W 2 where UW1. UW2 Rsi Rse Rs (3) are the thermal transmittances of the external and internal window. is the external surface resistance of the internal window when used alone. the method does not apply. To determine the thermal transmittance Ug of the combined glazing equation (4) shall be used: 1 Ug 1 / U g1 Rsi Rs Rse 1 / U g2 where Ug1. is the external surface resistance of the internal glazing when used alone. Ug2 glazing (single or multiple) 3 mm external Figure 6 . j is the thermal conductivity of glass or material layer j. respectively. the method does not apply.1.1 Single glazing The thermal transmittance of the single and laminated glazing. Ug. is the thermal resistance of the space between the internal and external glazing. 5. Rsi Rse Rs Typical values of Rsi and Rse are given in normative annex A and of Rs in the informative annex C. calculated according to equations (5) and (6). is the thickness of the glass pane or material layer j.2 Glazing 5.llustration of coupled windows (4) are the thermal transmittances of the external and internal glazing. dj Rsi is the internal surface resistance. shall be calculated with the following equation: Ug Rse 1 dj j (5) Rsi j where Rse is the external surface resistance.3 Coupled windows internal The thermal transmittance Uw of a system consisting of one frame and two separate sashes shall be calculated using equation (1). .2.Page 11 EN ISO 10077-1:2000 5. is the internal surface resistance of the external glazing when used alone. NOTE If the gap exceeds 3 mm and measures have not been taken to prevent excessive air exchange with external air. is the thickness of the glass pane or material layers j.3 Windows with closed shutters A shutter on the outside of a window introduces an additional thermal resistance. 5.j is the thermal resistance of air space j. dj Rsi is the internal surface resistance. Uws. The thermal transmittance of a window with closed shutters. R is the additional thermal resistance due to the air layer enclosed between the shutter and the window and the closed shutter itself (see figure 7). j is the thermal conductivity of glass or material layer j. is given by: U WS 1 (7) 1/U W R where Uw is the thermal transmittance of the window. and the shutter itself (see figure 7).Window with external shutter .Page 12 EN ISO 10077-1:2000 5.2. resulting from both the air layer enclosed between the shutter and the window. j j j (6) Rsi j where Rse is the external surface resistance. NOTE Typical values of Rs are given in informative annex C. Rs. R Rsh internal external shutter EMBED Figure 7 .2 Multiple glazing The thermal transmittance of multiple glazing Ug can be calculated according to EN 673 or by means of the following equation: 1 Ug Rse R dj s. 80 Rsh + 0.Page 13 EN ISO 10077-1:2000 The additional thermal resistance for five categories of shutter air permeability is given in the following expressions: – shutters with very high air permeability: R = 0. or multiple) Figure 8 . the typical values given in annexes G and H can be used. NOTE 2 The expression R for tight shutters is the best current estimate. is obtained using equation (13). which is of similar design to a window. 5. UD Ag U g Af U f lg g Ag Af (13) . If no measured or calculated values for Rsh are available. with connecting slats): R = 0.95 Rsh + 0.25 Rsh + 0.11 m2K/W (10) – shutters with low air permeability: R = 0. The above equations are valid for Rsh < 0. 2 NOTE 1 Annex H gives further information about the permeability of shutters.14 m2K/W (11) – tight shutters: R = 0.08 m2K/W (8) – shutters with high air permeability: R = 0.Illustration of door with glazing The thermal transmittance UD of a doorset.17 m2K/W (12) where Rsh is the thermal resistance of the shutter itself.4 Doors frame (fixed) sash (movable) glazing (single. For external or internal blinds use equations (8) to (12) with Rsh = 0. and future developments may lead to other values. roller shutters made of wood. plastic or metal. wooden venetian shutters with solid overlapping slats.09 m2K/W (9) – shutters with an average air permeability (for example solid wing shutters.3 m K/W.55 Rsh + 0. frame (fixed) sash (movable) opaque panel Figure 9 . Ag and lg are defined in clause 4. NOTE 1 Annex D gives typical values of Uf for different types of frame. nails. in accordance with ISO 8302. If the maximum relative error is higher than 10 % or the ratio of the thermal conductivities of the different materials is greater than 1:5 a numerical calculation in accordance with prEN ISO 10077-2 and/or EN ISO 10211-2 should be carried out. p If the opaque panel is thermally bridged at the edge by a less insulating spacer. this method includes the calculation of the maximum relative error which should be less than 10 %. If the doorset does not have a design similar to a window system then the thermal transmittance of the door leaves can be calculated in accordance with EN ISO 6946 provided that the ratio of the thermal conductivities of any two different materials in the door does not exceed 1:5 (screws.Page 14 EN ISO 10077-1:2000 where Af . The thermal transmittance of door leaves without a frame and without inhomogeneities (having different layers only perpendicular to the heat flow direction) can be measured in the guarded hot plate apparatus. prEN ISO 10077-2 gives a method for calculating the linear thermal transmittance.Schematic illustration of door with opaque panel If the door consists of frame. is the thermal transmittance of the opaque panel(s). is the thermal transmittance of the glazing. the effect of the bridging shall be taken into account in the same way as for glazing. In the case of single glazing the last term of the numerator in equation (13) shall be taken as zero (no spacer effect) because any correction is negligible. Ug is the thermal transmittance of the frame. Up is the linear thermal transmittance for opaque panels. and so on are excluded). then the following equation shall be used: UD AgU g ApU p AfU f lg g lp p Ag Ap Af (14) where Ap and lp are defined in clause 4. glazing and opaque panels. . NOTE 2 Typical values of are given in annex E. Uf is the linear thermal transmittance due to the combined thermal effects oglazing g spacer and frame. position. the values in informative annexes B to H may be used. by hot box measurement or numerical calculation in accordance with prEN ISO10077-2. is to be determined with the glazing replaced with a material of thermal conductivity not exceeding 0. – the presence and position of metal stiffening (for plastic frames only). – the type of glass and its thickness or its thermal properties and emissivity of its surfaces. – the internal developed frame area Ad. . Uf. EN ISO 6946 and ISO 8302. Ug.Page 15 EN ISO 10077-1:2000 6 Input data The thermal transmittance of the frame.e (only for metallic frames). – the position of the glass spacers or of the edge stiffening for opaque panels. 7. EN 674 or EN 675. description of any shutters. The thermal transmittance of the glazing. . is to be determined according to EN 673.e. which is taken into account by the linear thermal transmittance. – the thickness of wooden frames and the thickness of plastic and PUR–frame (polyurethane) material.i and the external developed frame area Ad. – the internal projected frame area Af. Other values to be used in the basic formulae can be obtained from annex A and EN 12524 or by means of prEN 1098. If measured or calculated data are not available.04 W/(mK). either tabulated in this standard or obtained by numerical calculations in accordance with prEN ISO 10077-2 or by measurement in accordance with prEN 12412-2. the sources of the numerical values of each parameter shall be identical for each door or window included in the comparison. – the thickness of gas spaces.i and the external projected frame area Af. height. – the number and thickness of air chambers (for plastic frames only). – the thickness and description of any opaque panels in the frame. If the results are to be used for comparison of the performance of different windows. the identification of the gas and the percentage assured to be present. In the case of metallic frames with pin-point connections the distance between the pinpoints shall be clearly indicated. Both Uf and Ug thus exclude the thermal interaction between the frame and the glazing (or opaque panel). type and number of thermal breaks (for metallic frames).1 Drawing of sections A technical drawing (preferably scale 1:1) giving the sections of all the different frame parts permitting verification of: – the thickness. 7 Report The calculation report shall include the following. d) If measured or calculated values are used for one of the three parameters the relevant standards shall be identified and it shall be confirmed that the values obtained correspond to the definitions of the areas given in this standard. the sources shall be given. 7. . – perimeter length of the glazing lg and/or of the opaque panels lp.3 Values used in the calculation a) If the informative annexes are used this shall be clearly stated and reference shall be made to the tables in the annexes.2 Drawing of the whole window or door A drawing of the whole window or door (seen from inside) with the following information: – glazed area Ag and/or opaque panel area Ap. 7.Page 16 EN ISO 10077-1:2000 7. Uf and values. a detailed calculation following EN 673 shall be given. – frame area: Af. Af and of the perimeter length lg and lp. calculated according to the standard shall be given with two significant figures.4 Presentation of results The thermal transmittance of the window or door. c) If a glazing not covered by the table in the annex C is used. b) If other sources are used to determine one or more of the Ug. It shall be ascertained that these other sources use the same definitions of the areas Ag. Surface thermal resistances Window position Internal Rsi 2 Vertical or inclination of the glazing to the horizontal such that 90° 60° External Rse 2 m K/W m K/W 0.8) for the inside and outside surfaces of the glazing.1 .0 W/(mK) should be used.04 Rsi for special cases.13 0. . for example a low emissivity coating on the outer surface of the interior pane. the following values for the surface resistances Rse and Rsi shall be used. Table A.Page 17 EN ISO 10077-1:2000 Annex A (normative) Internal and external surface thermal resistances For typical normal emissivities ( 0. Annex B (informative) Thermal conductivity of glass In the absence of specific information for the glass concerned the value 1. can be calculated according to EN 673. 173 15 0.Page 18 EN ISO 10077-1:2000 Annex C (informative) Thermal resistance of air spaces between glazing and thermal transmittance of coupled or double glazing Table C.376 0.182 0.259 0.247 0. Procedures for evaluating the effect of ageing on the thermal properties of glazed units are given in prEN 1279-1 and prEN 1279-3.190 0.197 0.132 0. for coupled and double windows Thickness of One side coated with a Both sides air space normal emissivity of: uncoated mm 0.1 .179 100 0.333 0.284 0.260 0.182 0.171 0.335 0. with both sides uncoated or with one side coated with a low emissivity layer. for spaces filled with air.1 gives some values of the thermal resistance Rs of air spaces for double glazing.211 0.4 0. calculated in accordance with EN 673. .211 0.162 0. For individual glazing units the emissivity and/or gas concentration may change with time.2 gives the thermal transmittance Ug of double and triple glazing filled with different gases. for a mean temperature of the glazing of 283 K and a temperature difference of 15 K between the two outer glazing surfaces.228 0.2 0.446 0.186 50 0.163 For wide air layers like in double windows or doors the calculation according to EN 673 does not lead to correct results.127 9 0. Table C.173 300 0. calculated according to EN 673.376 0.163 0. The data apply: – – – – for vertical windows or an inclination of the glazing to the horizontal such that 90 ° 60°. Table C.316 0. The values of the thermal transmittance in the table apply to the emissivities and gas concentrations given.247 0. In such cases more sophisticated calculation methods or measurements should be used.315 0.276 0. in m2K/W.154 12 0.363 0. For triple glazing the procedure in EN 673 should be used.Thermal resistance Rs of unventilated air spaces.8 6 0.406 0.298 0.189 0.1 0. 8 1.6 4-9-4-9-4 1.5 2.0 1.7 glass 0.0 4-6-4-6-4 2.1 2.89 glass 2 panes coated 0.0 2.1 Glass (normal Normal emissivity 0.6 2.9 0.3 1.8 0.6 2.1 2.7 1.3 2.2 0.9 2.5 1.7 2.2 4-6-4-6-4 1.6 2.6 2.2 glass 0.3 2.2 2.3 4-9-4 2.1 4-20-4 2.0 coated 4-9-4 2.5 1.9 1.6 1.5 1.7 2.3 1.8 3.2 glazing 2 panes coated 0.2 2.1 1.1 1.3 glass 0.2 1.0 1.1 coated 4-9-4 2.Thermal transmittance Ug of double and triple glazing filled with different gases Glazing Type Type of gas space (gas concentration 90 %) Uncoated Dimensions mm 4-6-4 3.7 2.6 4-6-4-6-4 1.8 1.7 1.Page 19 EN ISO 10077-1:2000 Table C.0 2.6 3.7 4-15-4 2.3 4-15-4 1.1 4-15-4 2.1 One pane 4-6-4 2.6 1.3 1.2 4-6-4-6-4 2.4 1.0 1.8 1.2 1.2 2.5 One pane 4-6-4 2.1 2 panes coated 0.0 glass 4-9-4 3.3 4-20-4 1.8 2.5 1.3 1.8 1. .4 2 panes Triple Air coated 0. Procedures for evaluating the effect of ageing on the thermal properties of glazed units are given in prEN 1279-1 and prEN 1279-3.2 1.9 2.4 4-6-4-6-4 1.7 1.0 2.1 One pane 4-6-4 2.3 2.7 1.0 2.2 1.2 4-9-4-9-4 1.6 1.7 2.6 1.7 1.6 2.7 4-20-4 2.1 4-12-4-12-4 1.3 2.0 0.5 2.1 1.9 0.0 4-9-4-9-4 2.9 1.0 0.9 2.89 glass) Argon Krypton SF6 4-12-4 2.1 4-9-4-9-4 1.0 2.6 2.2 0.6 2.3 0.7 2.4 1.9 1.6 4-12-4-12-4 1.0 2.1 NOTE The values of thermal transmittance in the table were calculated using EN 673.3 2.2 .3 2.2 2.7 4-6-4 2.2 4-12-4 1.05 Uncoated (normal) 0.3 4-9-4-9-4 1.8 1.3 4-12-4-12-4 1.4 4-12-4 1.3 2.5 1.6 2. They apply to the emissivities and gas concentration given.0 2.7 2.5 2.7 1.1 1.4 One pane Double coated glazing glass 0.0 2.2 1.6 coated 4-9-4 2.0 4-12-4-12-4 1.2 4-12-4-12-4 1.7 1.1 4-12-4 1.7 1. For individual glazing units the emissivity and/or gas concentrations may change with time.1 2.9 1.6 1.6 3.0 1.05 4-20-4 1.6 3.3 2.4 1.3 3.3 1.5 1.4 2.5 1.1 1.5 4-20-4 1.9 1.8 1.2 4-15-4 1.8 2.6 1.2 4-12-4 2.8 1.0 0.0 1.1 0.6 2.6 3.4 4-15-4 1.4 1. which can be used in the absence of specific measured or calculated information for the frame concerned.1.2 and figure D.4 cannot be used for sliding windows but the principle of equation (1) can be used.1. having a wide range of geometric shapes but having similar thermal properties.4. If no other information is available. – the ratio of the width of the thermal break to the frame projection width. Values for frames which are not described in the tables should be determined by measurements or calculations. as can values of Uf obtained by direct measurements using hot box methods in accordance with prEN 12412-2. – the conductivity of the thermal break material.Page 20 EN ISO 10077-1:2000 Annex D (informative) Thermal transmittance of frames Values of Uf evaluated by numerical calculation methods (finite element.13 m K/W and Rse = 0. figure D. They include the effect of the developed areas. 1) The values of Uf in table D. A document specifying practical procedures for evaluating the thermal properties of such "profile systems" is under preparation. material and design of the thermal break. .4 are based on a large number of measured values as well as mathematically evaluated values determined using numerical calculation methods. the important parameters such as the size. 1) Especially in the case of aluminium profiles with thermal breaks there is the problem that the thermal transmittance of the frame is influenced by different construction characteristics. The values in this annex are based on Rsi = 0. 2 2 It is common practice to produce "Profile Systems" comprising a large number of different frames. finite difference) in accordance with prEN ISO10077-2 can be used as input data for calculations.2 and figure D. figure D. such as: – the distance a between the aluminium sections. This is because in these groups of frames. – the width b of the material of the thermal break zones.1. Future development should not be impeded by tabulated Uf values. are the same. All the values shown in table D. A thermal break can be considered as such only if it completely separates the metal sections on the cold side from the metal sections on the warm side.2 and figure D. All values given in this annex refer to the vertical position only.04 m K/W. Typical values for common types of frames are given in table D. figure D. the values derived from the following tables and graphs can be used in the calculations for the corresponding frame types. 0 three hollow chambers 1) With a distance between wall surfaces of hollow chambers of at least 5 mm (refer to figure D.1 .1 can be used for frames without metal reinforcements.1 .Thermal transmittances for plastic frames with metal reinforcements Frame material Polyurethane Uf W/(m2K) 2.8 Frame type with metal core thickness of PUR 5 mm PVC-hollow 1) profiles external internal 2. Table D.2 two hollow chambers external internal 2.Page 21 EN ISO 10077-1:2000 Plastic frames If no other data are available.1). Dimensions in millimetres 5 Figure D. . the values in table D.Hollow chamber in plastic frame Other plastic profile sections should be measured or calculated. For definition of the thickness of the frame see figure D.Thermal transmittances for wooden frames and metal-wood frames (see figure D.0 soft wood (density 500 kg/m3) = 0. Uf in (W/m2K) 3.Definition of the thickness df of the frame for various window systems .13 W/(mK) 1.3) depending on the frame thickness df wood metal-wood d2 metal-wood d2 internal: right side of frame section d2 sash df frame d1 d1 d2 d3 d2 d3 d1d 2 2 external: left side of frame section d1 metal-wood wood wood d4 d2 d3 sash df d d j sa jf 2 frame d1 d1 d1 Figure D.0 hard wood (density 700 kg/m3) = 0.18 W/(mK) 2.0 50 100 150 Thickness of the frame df in mm Figure D.Page 22 EN ISO 10077-1:2000 Wood frames Values for wood frames can be taken from figure D.3 .3.2. For Uf.2 . the values correspond to a moisture content of 12 %. d. 2 Ufo in W/(m ·K) 4. 2 For metal frames without a thermal break. i / Ad.Uf0 -values for metal frames with thermal break The thermal resistance of the frame. take Ufo from the solid line in figure D.9 W/(m ·K).metal frames with thermal breaks corresponding to the sections illustrated in figure D.0 3.Page 23 EN ISO 10077-1:2000 Metal frames The thermal transmittance of metal frames can be determined by measurement using hot box methods in accordance with prEN 12412-2 or by numerical calculation in accordance with prEN ISO 10077-2. subject to restrictions on the thermal conductivity and widths of the thermal breaks. in mm NOTE The shaded area indicates the range of values obtained from many measurements on frames carried out in several European countries. use Ufo = 5. i Rf Rse Af.4 .6.4. e (D. from Uf 1 Rsi Af.1) and the thermal transmittance of the frame.0 2.metal frames without a thermal break.0 0 4 8 12 16 20 24 28 32 36 Smallest distance between opposite metal sections.2) . is given by 1 0. . e / Ad.5 and figure D. If such data are not available. Rf. values of Uf can be obtained by the following procedure for: . Values obtained by such methods should be used when available. For metal frames with thermal breaks.17 Rf U f0 (D. Uf. derived from the surface temperature difference across the frame. Figure D. in preference to the method given in this annex. e. b j 0.6 .3bf j bf Figure D.Section Type 2: Thermal break with a thermal conductivity below 0. calculated as if the developed area were equal to the projected area.2 W/(mK) d b1 d b2 d is the smallest distance between opposite aluminium sections of the thermal break. 2 Rsi is the appropriate internal surface resistance of the frame. in W/(m K). Ad.K). bj is the width of thermal break j. 2 Rse is the appropriate external surface resistance of the frame. bf is the width of the frame.5 .i. Af. .1 < 0. b b4 j 0. Thermal conductivity of thermal break materials 0. resulting from the thermal transmittance of the frame taking into account the appropriate surface resistance.e.3 W/(mK) Thermal conductivity of thermal break materials 0. bf is the width of the frame.6 is not valid. are the areas as defined in clause 4.Page 24 EN ISO 10077-1:2000 where Ad. 2 Uf0 is the thermal transmittance. bj is the width of thermal break j. the definition in figure D. in m K/W.i.1 W/(m. expressed in square metres. in m K/W.3 W/(mK) d b1 b2 d b3 d is the smallest distance between opposite aluminium sections of the thermal break. 2 Rf is the thermal resistance of the frame section. Af.2 W/(m·K) If the thermal conductivity of the termal break material is below 0. in m K/W.2 < 0.Section Type 1: Thermal break with a thermal conductivity below 0.2bf j bf Figure D. The linear transmittance is mainly effected by the conductivity of the spacer material. Ug. On the other hand.04 0.3 W/(m K) and triple 2 glazing with low emissivity Ug 0. is applicable in the absence of the glazing. uncoated glass. Table E. Ug 1. air or gas space W/(m·K) W/(m·K) 0. glazing and spacer.08 0 0.1 indicates the values of for a specific range of types of frames and glazing. 2) . Double glazing with low emissivity.06 0.02 plastic frame Metal frame with thermal break Metal frame without thermal break Values for spacers not covered by the table can be determined by numerical calculation in accordance with prEN ISO 10077-2.Page 25 EN ISO 10077-1:2000 Annex E (informative) Linear thermal transmittance of frame/glazing junction The thermal transmittance of the glazing. .1 . The linear thermal transmittance describes the additional heat conduction due to the interaction between frame. 2) 2 These values are evaluated for double glazings with low emissivity.7 W/(m K). For aluminium and steel (not stainless steel) glass spacers table E.06 0. Uf. triple glazing with two low emissivity air or gas space coatings. is applicable to the central area of the glazing and does not include the effect of the glass spacers at the edge of the glazing. for aluminium and steel (not stainless steel) glass spacers Frame material Wood frame and Double or triple glazing. the thermal transmittance of the frame.Values of the linear thermal transmittance. 5 1.9 2.8 0.1 1.9 2.4 1.7 1.1 3.3 1.0 2.6 1.9 2.3 2.5 1.2 1.0 3.8 4.3 1. Table F.2 1.5 1.1 6.8 2.8 2.6 3.8 2.1 2.5 2.0 2.7 2.8 3.9 3.5 1.2 3.6 3.6 1.1 3.1 1.6 2.1 2.4 2.4 2.3 2.3 1.4 1.8 2.2 2.3 2.9 3.7 2.3 2.0 2.3 2.9 2.1 1.1 3.1 3.3 2.0 2.7 2.1 1.4 2.2 2.6 2.6 1.2 1.5 1.2 2.5 3.7 2.3 2.4 3.8 2.4 2.5 2.4 2.3 1.4 1.6 2.5 0.9 3.5 1.3 2.Thermal transmittances for windows with fraction of the frame area 30 % of the whole window area Type of glazing Uf Ug W/(mK) W/(m K) frame area 30 % Single Double Triple 1.1 2.6 1.8 1.0 3.0 1.7 0.2 3.3 2.2 1.9 2.5 3.6 1.1 3.4 2. Values for windows with frame area fractions not equal to 30 % have to be evaluated by means of the equations of the main part of the standard.9 2.2 1.8 7.0 2.4 3.4 2.6 1.9 0.4 1.1 1.6 1. .3 1.3 2.3 1.0 2.1 2.1 3.5 2.0 5.2 4.9 1.8 3.6 1.0 2.0 2.7 2.3 4.7 1.5 3.8 3.5 2.2 1.1 2.9 1.3 1.4 4. Values for windows with other frame area fractions can be evaluated by means of the equations of the main part of that standard.9 1.0 2.2 2.6 1.3 1.0 2.5 1.9 2.8 2.3 4.7 4.5 2.1 2.1 2.5 NOTE The calculation has been made using -values according to annex E.6 1.8 2.6 4.7 1.4 2.6 1.9 2.8 1.1 and table F.1 1.2 1.7 1.0 2.8 0.9 1.4 1.1 2.0 2.8 2.7 2.2 give typical values calculated by the method in this standard using linear thermal transmittances from annex E.1 2.9 1.2 3.5 1.9 3.5 2.7 2.1 2.7 1.4 2.0 2.7 2.7 3.1 2.1 1.7 1.2 3.2 3.7 2.3 2.3 2.4 3.Page 26 EN ISO 10077-1:2000 Annex F (informative) Thermal transmittance of windows Table F.2 2.6 2.5 4.0 2.4 2.3 3.9 2.5 4.3 1.9 2.5 1.2 2.9 2.7 1.7 1.6 2.7 1.0 1.1 2.6 1.4 2.1 .1 2.9 2.0 3.6 1.7 1.0 5.9 3.6 2.1 1.2 2.5 1.7 1.2 2.7 2.4 1.6 4.6 0.8 2.4 3.7 1.9 2.9 2.3 2.9 5.4 3.8 3.8 1.8 2.1 2.5 2. 1 3.9 1.5 1.1 2.9 2.2 2.0 2.0 1.1 2.8 2.8 2.9 1.0 0.3 1.8 2.0 2.2 2.0 3.1 2.9 2.8 1.6 3.5 1.4 1.1 2.7 1.3 2.2 3.3 1.1 2.3 2.6 2.0 3.1 2.3 2.7 2.0 2.3 2.6 2.7 1.6 2.2 5.1 2.0 3.6 2.2 2.3 2.4 3.9 2.5 0.2 1.2 2.5 1.7 1.7 1.5 1.7 1.0 2.0 2.9 1.3 1.4 1.0 2.2 2.5 2.3 1.4 2.4 2.0 1.8 70 5.0 1.2 2.8 2.2 1.3 1.9 1.4 2.4 1.9 1.1 1.8 2.7 2.7 2.9 3.4 1.2 0.9 2.7 1.8 1. .1 1.0 2.7 0.8 NOTE The calculation has been made using -values according to annex E.2 1.5 1.2 2.3 3.Page 27 EN ISO 10077-1:2000 Table F.2 1.0 5.0 2.8 1.6 2.5 2.5 2.3 2.4 2.2 5.9 1.6 2.1 3.1 1.2 2.7 2.7 2.7 2.9 2.1 1.8 1.5 2.3 2.3 2.0 1.8 3.8 4. Values for windows with frame area fractions not equal to 20 % have to be evaluated by means of the equations of the main part of the standard.3 3.3 1.4 1.3 2.5 1.8 2.7 4.4 1.Thermal transmittances for windows with fraction of the frame area 20 % of the whole window area Type of Ug Uf glazing W/(mK) W/(mK) frame area 20 % Single Double Triple 1.4 3.2 2.0 3.7 1.4 2.5 2.3 1.2 1.1 1.9 3.3 2.3 0.2 2.4 2.1 2.2 2.2 2.2 1.4 1.6 1.9 2.1 2.1 1.3 5.0 3.6 1.5 1.7 1.1 2.8 1.5 1.5 4.6 1.0 3.7 1.3 2.0 1.5 1.9 3.0 2.8 1.9 2.0 3.1 5.8 1.6 1.6 1.7 1.0 1.9 5.9 1.9 2.7 0.1 2.4 2.2 3.4 1.6 1.6 1.8 1.7 3.4 3.6 1.4 1.8 1.1 2.5 1.8 4.1 1.3 2.2 3.0 2.1 3.6 2.0 3.8 1.6 2.8 1.5 2.5 2.3 2.3 2.4 1.2 2.9 3.6 3.4 3.7 3.9 3.8 0.4 2.4 3.5 1.4 1.9 2.2 .7 2.0 2.5 2.9 2.0 2.8 2.8 2.9 1.6 1.6 1.6 3. 1 gives some typical values of shutter thermal resistance and the corresponding values of R.01 0. R. Rsh.26 0. Low air permeability 0.13 0.3.15 0. Table G.15 0.14 0.12 aluminium Roller shutters of wood and plastic 0.12 0. R.20 0.30 .Page 28 EN ISO 10077-1:2000 Annex G (informative) Additional thermal resistance for windows with closed shutters When the thermal resistance of the shutter itself.Additional thermal resistance.22 thickness 1) The definition of the air permeability of shutters is given in annex H.22 0.1 . should be obtained using the appropriate expression in 5.10 0. is known (by calculation or by measurement) the additional thermal resistance. Table G. 25 mm to 30 mm 0.19 filling Shutters of wood.09 0. for windows with closed shutters Shutter type Typical thermal resistance of shutter Rsh 2 m K/W Additional thermal resistances at specific air permeability of the shutters 1) R 2 m K/W High air permeability Average air permeability Roller shutters of 0. which can be used in the absence of values of Rsh obtained from measurement or calculation.16 without foam filling Roller shutters of plastic with foam 0. top and side on the shutter (see figure H. since gaps at the side influence the permeability less than the gaps at the top and bottom. b sh b1 b 2 b 3 (H.1.1) where b1.1 . b3 is included for one side only. b2 and b3 are the average edge gaps at the bottom.Page 29 EN ISO 10077-1:2000 Annex H (informative) Permeability of shutters For the different types of shutter. the permeability criterion can be expressed in terms of an effective total gap bsh between the shutter and its surround according to figure H.1). b2 b2 external b3 shutter b1 b1 internal external b3 Figure H.Definition of edge gaps internal . or brush-type joints on both sides of the curtain or if the end of the curtain is pressed by a device (spring) against a sealing material at the inner surface of the outer side of the roller shutter box. NOTE 2 For shutters of permeability class 5 the following criteria apply: a) Roller shutters The edge gaps at the sides and the bottom are considered equal to 0 if strip gaskets are supplied in the guide rails and the final lath. An alternative method to establish that a shutter is class 5 is to verify by measurement that the 3 2 air flow through the shutter is less or equal than 10 m /(hm ) under a pressure drop of 10 Pa.Page 30 EN ISO 10077-1:2000 Table H. there should be no openings within the shutter itself.Relationship between permeability and effective total edge gap between shutter and its surround Class Permeability of shutter bsh mm 1 Very high permeability bsh > 35 2 High air permeability 15 bsh < 35 3 Average air permeability 8 4 Low air permeability 5 Tight bsh < 15 bsh 8 bsh 3 and b1+b3=0 or b2+b3= 0 NOTE 1 For permeability classes 2 and above.1 . . The gap at the top is considered equal to 0 if the entrance to the roller shutter box is fitted with lips . b) Other shutters Effective presence of strip gaskets on three sides and the gap at the fourth side less than 3 mm. respectively. Clause 6 Deviation Germany: Verordnung über einen energiesparenden Wärmeschutz bei Gebäuden (Wärmeschutzverordnung WärmeschutzV) Vom 16.Page 31 EN ISO 10077-1:2000 Annex ZA (informative) A-deviations A-deviation: National deviation due to regulations. . August 1994. In the relevant CEN/CENELEC countries these A-deviations are valid instead of the provisions of the European Standard until they have been removed. the alteration of which is for the time being outside the competence of the CEN/CENELEC member. This European Standard does not fall under any Directive of the EC. The German regulation specifies that the design thermal transmittance for glazing as well as windows and window doors shall be in accordance with tables 2 to 6 of DIN V 4108-4:1998-10. of necessary details such as symbols. stored in a retrieval system or transmitted in any form or by any means – electronic. international and foreign standards publications should be addressed to Customer Services. and size. Tel: +44 (0)20 8996 9001. Fax: +44 (0)20 8996 7001. Except as permitted under the Copyright. Email:
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