BRITISH STANDARD
Thermal 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
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", the secretariat of which is held by SIS , in collaboration with Technical Committee ISO/TC 163 "Thermal insulation". 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 2001, and conflicting national standards shall be withdrawn at the latest by January 2001. For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this standard. 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, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. 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. It contains two parts. Part 1 deals with the simplified calculation of the thermal transmittance of windows and doors with or without shutters. Part 2 covers the numerical calculation (twodimensional) of the thermal transmittance of frame profiles.
Introduction The method described in this standard is used to evaluate the thermal transmittance of windows and doors, or as part of the determination of the energy use of a building. 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”. In some countries the calculation of the thermal transmittance of windows forms part of their national regulations. Information about national deviations from this standard due to regulations are given in annex ZA.
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, with and without shutters. It allows for: - different types of glazing (glass or plastics; single or multiple glazing; with or without low emissivity coatings; with spaces filled with air or other gases); - various types of frames (wood; plastic; metallic with and without thermal barrier; metallic with pinpoint metallic connections or any combination of materials); - where appropriate, the additional thermal resistance introduced by different types of shutters, depending on their air permeability. Curtain walls and other structural glazings, which are not fitted in a frame, are excluded from this standard. Roof windows are also excluded because of their complex geometrical frame sections. Default values for glazings, frames and shutters are given in the informative annexes. 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. The calculation does not include: – – – –
effects of solar radiation; heat transfer caused by air leakage; calculation of condensation; ventilation of air spaces in double and coupled windows.
Page 5 EN ISO 10077-1:2000
2
Normative references
This standard incorporates by dated or undated reference, 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 standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publications referred to applies. 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 - Insulating glass units - Part 1: Generalities and dimensional tolerances Glass in building - Insulating glass units - Part 3: Initial type testing on gas-filled insulating glass units; gas leakage rate Windows, doors and shutters - 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 - Calculation of thermal transmittance - Part 2: Numerical method for frames (ISO/DIS 10077-2) Thermal bridges in building construction - 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
Page 6 EN ISO 10077-1:2000
3
Definitions, symbols and units
3.1
Definitions
For the purposes of this standard, the definitions given in EN 673 and EN ISO 7345 apply. In clause 4 of this standard, descriptions are given of a number of geometrical characteristics of glazing and frame.
3.2
Symbols
Symbol A R T U b d l q
3.3
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,i internal
frame
external Ad,e
Figure 1 - 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
Page 7 EN ISO 10077-1:2000
4
Geometrical characteristics
4.1
Glazed area, 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. Any overlapping of gaskets is ignored.
4.2
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. If the perimeters are different on either side of the pane or panel then the larger of the two shall be used, see figure 2.
lg
lg
glass
Ag
Figure 2 - Illustration of glazed area and perimeter
4.3
Frame areas
For the definition of the areas see also figure 3. 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. Frame area Af The frame area is the larger of the two projected areas seen from both sides. Ad,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). Ad,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).
Af,i
Page 8 EN ISO 10077-1:2000
4.4
Window area The window area Aw is the sum of the frame area Af and the glazing area Ag (or the panel area Ap).
Af,i = Af
A1
Ag
A3
A2
internal
A4
sash (movable) frame (fixed)
A8 A7
A5
A6
Af,e
Aw
NOTE Af = max (Af,i ; Af,e) Aw = Af + Ag Ad,i = A1 + A2 + A3 + A4 Ad,e = A5 + A6 + A7 + A8 Figure 3 - Illustration of the various areas
external
Page 9 EN ISO 10077-1:2000
5
Calculation of thermal transmittance
5.1
Windows
5.1.1 Single windows
frame (fixed)
sash (movable)
glazing (single or multiple)
Figure 4 - 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; is the thermal transmittance of the frame; Uf is the linear thermal transmittance due to the combined thermal effects of glazing, g spacer and frame; and the other symbols are defined in clause 4.
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. When opaque panels are used instead of some of the glazing, 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); Up p is the linear thermal transmittance for the opaque panel(s). If the opaque panel is thermally bridged at the edge by a less insulating spacer, the effect of the bridging shall be taken into account in the same way as for glazing; otherwise p = 0. NOTE Typical values of the linear thermal transmittance are given in annex E. prEN ISO 10077-2 gives a method for calculating linear thermal transmittance. prEN 12412-2 gives a method for measuring the linear thermal transmittance.
Page 10 EN ISO 10077-1:2000
5.1.2 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 - 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; respectively, calculated according to equation (1); is the internal surface resistance of the external window when used alone; is the external surface resistance of the internal window when used alone; is the thermal resistance of the space between the glazing in the two windows.
Typical values of Rsi and Rse are given in normative annex A and of Rs in the informative annex C. NOTE If the gap exceeds 3 mm and measures have not been taken to prevent excessive air exchange with external air, the method does not apply.
Page 11 EN ISO 10077-1:2000
5.1.3 Coupled windows
internal
The thermal transmittance Uw of a system consisting of one frame and two separate sashes shall be calculated using equation (1). 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, Ug2
glazing (single or multiple)
3 mm
external
Figure 6 - llustration of coupled windows
(4)
are the thermal transmittances of the external and internal glazing; respectively, calculated according to equations (5) and (6); is the internal surface resistance of the external glazing when used alone; is the external surface resistance of the internal glazing when used alone; is the thermal resistance of the space between the internal and external glazing.
Rsi Rse Rs
Typical values of Rsi and Rse are given in normative annex A and of Rs in the informative annex C. NOTE If the gap exceeds 3 mm and measures have not been taken to prevent excessive air exchange with external air, the method does not apply.
5.2
Glazing
5.2.1 Single glazing The thermal transmittance of the single and laminated glazing, Ug, shall be calculated with the following equation:
Ug Rse
1 dj
j
(5)
Rsi
j
where Rse is the external surface resistance; j is the thermal conductivity of glass or material layer j; is the thickness of the glass pane or material layer j; dj Rsi is the internal surface resistance.
Page 12 EN ISO 10077-1:2000
5.2.2 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, j
j
j
(6)
Rsi
j
where Rse is the external surface resistance; j is the thermal conductivity of glass or material layer j; is the thickness of the glass pane or material layers j; dj Rsi is the internal surface resistance; Rs,j is the thermal resistance of air space j.
NOTE Typical values of Rs are given in informative annex C.
5.3
Windows with closed shutters
A shutter on the outside of a window introduces an additional thermal resistance, resulting from both the air layer enclosed between the shutter and the window, and the shutter itself (see figure 7). The thermal transmittance of a window with closed shutters, Uws, is given by: U WS
1
(7)
1/U W R
where Uw is the thermal transmittance of the window; 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).
R Rsh
internal
external
shutter
EMBED Figure 7 - Window with external shutter
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 = 0,08 m2K/W
(8)
– shutters with high air permeability: R = 0,25 Rsh + 0,09 m2K/W
(9)
– shutters with an average air permeability (for example solid wing shutters, wooden venetian shutters with solid overlapping slats, roller shutters made of wood, plastic or metal, with connecting slats):
R = 0,55 Rsh + 0,11 m2K/W
(10)
– shutters with low air permeability: R = 0,80 Rsh + 0,14 m2K/W
(11)
– tight shutters: R = 0,95 Rsh + 0,17 m2K/W
(12)
where Rsh is the thermal resistance of the shutter itself. The above equations are valid for Rsh < 0,3 m K/W. If no measured or calculated values for Rsh are available, the typical values given in annexes G and H can be used. For external or internal blinds use equations (8) to (12) with Rsh = 0. 2
NOTE 1 Annex H gives further information about the permeability of shutters. NOTE 2 The expression R for tight shutters is the best current estimate, and future developments may lead to other values.
5.4
Doors
frame (fixed)
sash (movable)
glazing (single, or multiple)
Figure 8 - Illustration of door with glazing
The thermal transmittance UD of a doorset, which is of similar design to a window, is obtained using equation (13).
UD
Ag U g Af U f lg g Ag Af
(13)
Page 14 EN ISO 10077-1:2000 where Af , Ag and lg are defined in clause 4; is the thermal transmittance of the glazing; Ug is the thermal transmittance of the frame; Uf is the linear thermal transmittance due to the combined thermal effects oglazing g spacer and frame; 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.
frame (fixed)
sash (movable) opaque panel
Figure 9 - Schematic illustration of door with opaque panel
If the door consists of frame, glazing and opaque panels, 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; is the thermal transmittance of the opaque panel(s); Up is the linear thermal transmittance for opaque panels. p If the opaque panel is thermally bridged at the edge by a less insulating spacer, the effect of the bridging shall be taken into account in the same way as for glazing. NOTE 1 Annex D gives typical values of Uf for different types of frame. prEN ISO 10077-2 gives a method for calculating the linear thermal transmittance. NOTE 2 Typical values of are given in annex E. 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, in accordance with ISO 8302. 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, nails, and so on are excluded); this method includes the calculation of the maximum relative error which should be less than 10 %. 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.
Page 15 EN ISO 10077-1:2000
6
Input data
The thermal transmittance of the frame, Uf, is to be determined with the glazing replaced with a material of thermal conductivity not exceeding 0,04 W/(mK), by hot box measurement or numerical calculation in accordance with prEN ISO10077-2. The thermal transmittance of the glazing, Ug, is to be determined according to EN 673, EN 674 or EN 675. Both Uf and Ug thus exclude the thermal interaction between the frame and the glazing (or opaque panel), which is taken into account by the linear thermal transmittance, , 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. Other values to be used in the basic formulae can be obtained from annex A and EN 12524 or by means of prEN 1098, EN ISO 6946 and ISO 8302. If measured or calculated data are not available, the values in informative annexes B to H may be used. If the results are to be used for comparison of the performance of different windows, the sources of the numerical values of each parameter shall be identical for each door or window included in the comparison.
7
Report
The calculation report shall include the following.
7.1
Drawing of sections
A technical drawing (preferably scale 1:1) giving the sections of all the different frame parts permitting verification of: – the thickness, height, position, type and number of thermal breaks (for metallic frames); – the number and thickness of air chambers (for plastic frames only); – the presence and position of metal stiffening (for plastic frames only); – the thickness of wooden frames and the thickness of plastic and PUR–frame (polyurethane) material; – the thickness of gas spaces, the identification of the gas and the percentage assured to be present; – the type of glass and its thickness or its thermal properties and emissivity of its surfaces; – the thickness and description of any opaque panels in the frame; – the internal projected frame area Af,i and the external projected frame area Af,e; – the internal developed frame area Ad,i and the external developed frame area Ad,e (only for metallic frames); – the position of the glass spacers or of the edge stiffening for opaque panels; description of any shutters. In the case of metallic frames with pin-point connections the distance between the pinpoints shall be clearly indicated.
Page 16 EN ISO 10077-1:2000
7.2
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; – frame area: Af; – perimeter length of the glazing lg and/or of the opaque panels lp.
7.3
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. b) If other sources are used to determine one or more of the Ug, Uf and values, the sources shall be given. It shall be ascertained that these other sources use the same definitions of the areas Ag, Af and of the perimeter length lg and lp. c) If a glazing not covered by the table in the annex C is used, a detailed calculation following EN 673 shall be given. 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.
7.4
Presentation of results
The thermal transmittance of the window or door, calculated according to the standard shall be given with two significant figures.
Page 17 EN ISO 10077-1:2000
Annex A (normative) Internal and external surface thermal resistances For typical normal emissivities ( 0,8) for the inside and outside surfaces of the glazing, the following values for the surface resistances Rse and Rsi shall be used. Table A.1 - 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
0,13
0,04
Rsi for special cases, for example a low emissivity coating on the outer surface of the interior pane, can be calculated according to EN 673.
Annex B (informative) Thermal conductivity of glass In the absence of specific information for the glass concerned the value 1,0 W/(mK) should be used.
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.1 gives some values of the thermal resistance Rs of air spaces for double glazing, calculated according to EN 673. The data apply: – – – –
for vertical windows or an inclination of the glazing to the horizontal such that 90 ° 60°; for spaces filled with air; with both sides uncoated or with one side coated with a low emissivity layer; for a mean temperature of the glazing of 283 K and a temperature difference of 15 K between the two outer glazing surfaces.
For triple glazing the procedure in EN 673 should be used.
Table C.1 - Thermal resistance Rs of unventilated air spaces, in m2K/W, for coupled and double windows Thickness of
One side coated with a
Both sides
air space
normal emissivity of:
uncoated
mm
0,1
0,2
0,4
0,8
6
0,211
0,190
0,163
0,132
0,127
9
0,298
0,259
0,211
0,162
0,154
12
0,376
0,316
0,247
0,182
0,173
15
0,446
0,363
0,276
0,197
0,186
50
0,406
0,335
0,260
0,189
0,179
100
0,376
0,315
0,247
0,182
0,173
300
0,333
0,284
0,228
0,171
0,163
For wide air layers like in double windows or doors the calculation according to EN 673 does not lead to correct results. In such cases more sophisticated calculation methods or measurements should be used. Table C.2 gives the thermal transmittance Ug of double and triple glazing filled with different gases, calculated in accordance with EN 673. The values of the thermal transmittance in the table apply to the emissivities and gas concentrations given. For individual glazing units the emissivity and/or gas concentration may change with time. Procedures for evaluating the effect of ageing on the thermal properties of glazed units are given in prEN 1279-1 and prEN 1279-3.
Page 19 EN ISO 10077-1:2000
Table C.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
3,3
3,0
2,8
3,0
glass
4-9-4
3,0
2,8
2,6
3,1
Glass
(normal
Normal emissivity
0,89
glass)
Argon
Krypton
SF6
4-12-4
2,9
2,7
2,6
3,1
4-15-4
2,7
2,6
2,6
3,1
4-20-4
2,7
2,6
2,6
3,1
One pane
4-6-4
2,9
2,6
2,2
2,6
coated
4-9-4
2,6
2,3
2,0
2,7
glass
0,4
One pane Double
coated
glazing
glass
0,2
4-12-4
2,4
2,1
2,0
2,7
4-15-4
2,2
2,0
2,0
2,7
4-20-4
2,2
2,0
2,0
2,7
4-6-4
2,7
2,3
1,9
2,3
4-9-4
2,3
2,0
1,6
2,4
4-12-4
1,9
1,7
1,5
2,4
4-15-4
1,8
1,6
1,6
2,5
4-20-4
1,8
1,7
1,6
2,5
One pane
4-6-4
2,6
2,2
1,7
2,1
coated
4-9-4
2,1
1,7
1,3
2,2
4-12-4
1,8
1,5
1,3
2,3
4-15-4
1,6
1,4
1,3
2,3
4-20-4
1,6
1,4
1,3
2,3
glass
0,1
One pane
4-6-4
2,5
2,1
1,5
2,0
coated
4-9-4
2,0
1,6
1,3
2,1
4-12-4
1,7
1,3
1,1
2,2
4-15-4
1,5
1,2
1,1
2,2
glass
0,05
Uncoated (normal)
0,89
glass 2 panes coated
0,4
2 panes Triple
Air
coated
0,2
glazing 2 panes coated
0,1
2 panes coated
0,05
4-20-4
1,5
1,2
1,2
2,2
4-6-4-6-4
2,3
2,1
1,8
2,0
4-9-4-9-4
2,0
1,9
1,7
2,0
4-12-4-12-4
1,9
1,8
1,6
2,0
4-6-4-6-4
2,0
1,7
1,4
1,6
4-9-4-9-4
1,7
1,5
1,2
1,6
4-12-4-12-4
1,5
1,3
1,1
1,6
4-6-4-6-4
1,8
1,5
1,1
1,3
4-9-4-9-4
1,4
1,2
0,9
1,3
4-12-4-12-4
1,2
1,0
0,8
1,4
4-6-4-6-4
1,7
1,3
1,0
1,2
4-9-4-9-4
1,3
1,0
0,8
1,2
4-12-4-12-4
1,1
0,9
0,6
1,2
4-6-4-6-4
1,6
1,3
0,9
1,1
4-9-4-9-4
1,2
0,9
0,7
1,1
4-12-4-12-4
1,0
0,8
0,5
1,1
NOTE The values of thermal transmittance in the table were calculated using EN 673. They apply to the emissivities and gas concentration given. For individual glazing units the emissivity and/or gas concentrations may change with time. Procedures for evaluating the effect of ageing on the thermal properties of glazed units are given in prEN 1279-1 and prEN 1279-3.
Page 20 EN ISO 10077-1:2000
Annex D (informative) Thermal transmittance of frames Values of Uf evaluated by numerical calculation methods (finite element, finite difference) in accordance with prEN ISO10077-2 can be used as input data for calculations, as can values of Uf obtained by direct measurements using hot box methods in accordance with prEN 12412-2. If no other information is available, the values derived from the following tables and graphs can be used in the calculations for the corresponding frame types. All values given in this annex refer to the vertical position only. Typical values for common types of frames are given in table D.1, figure D.2 and figure D.4, which can be used in the absence of specific measured or calculated information for the frame concerned. All the values shown in table D.1, figure D.2 and figure D.4 are based on a large number of measured values as well as mathematically evaluated values determined using numerical calculation methods. They include the effect of the developed areas. Future development should not be impeded by tabulated Uf values. Values for frames which are not described in the tables should be determined by measurements or calculations. 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, such as: – the distance a between the aluminium sections; – the width b of the material of the thermal break zones; – the conductivity of the thermal break material; – the ratio of the width of the thermal break to the frame projection width. 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. The values in this annex are based on Rsi = 0,13 m K/W and Rse = 0,04 m K/W. 2
2
It is common practice to produce "Profile Systems" comprising a large number of different frames, having a wide range of geometric shapes but having similar thermal properties. This is because in these groups of frames, the important parameters such as the size, material and design of the thermal break, are the same. A document specifying practical procedures for evaluating the thermal properties of such "profile systems" is under preparation.
1)
The values of Uf in table D.1, figure D.2 and figure D.4 cannot be used for sliding windows but the principle of equation (1) can be used.
Page 21 EN ISO 10077-1:2000
Plastic frames If no other data are available, the values in table D.1 can be used for frames without metal reinforcements. Table D.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
2,2
two hollow chambers
external
internal
2,0 three hollow chambers 1)
With a distance between wall surfaces of hollow chambers of at least 5 mm (refer to figure D.1).
Dimensions in millimetres
5
Figure D.1 - Hollow chamber in plastic frame
Other plastic profile sections should be measured or calculated.
Page 22 EN ISO 10077-1:2000
Wood frames Values for wood frames can be taken from figure D.2. For Uf, the values correspond to a moisture content of 12 %. For definition of the thickness of the frame see figure D.3. Uf in (W/m2K) 3,0
hard wood (density 700 kg/m3) = 0,18 W/(mK)
2,0
soft wood (density 500 kg/m3) = 0,13 W/(mK) 1,0 50
100
150
Thickness of the frame df in mm Figure D.2 - Thermal transmittances for wooden frames and metal-wood frames (see figure D.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.3 - Definition of the thickness df of the frame for various window systems
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. Values obtained by such methods should be used when available, in preference to the method given in this annex. If such data are not available, values of Uf can be obtained by the following procedure for: - metal frames without a thermal break; - metal frames with thermal breaks corresponding to the sections illustrated in figure D.5 and figure D.6, subject to restrictions on the thermal conductivity and widths of the thermal breaks. 2
For metal frames without a thermal break, use Ufo = 5,9 W/(m ·K). For metal frames with thermal breaks, take Ufo from the solid line in figure D.4. 2 Ufo in W/(m ·K)
4,0
3,0
2,0
0
4
8
12
16
20
24
28
32
36
Smallest distance between opposite metal sections, d, in mm
NOTE The shaded area indicates the range of values obtained from many measurements on frames carried out in several European countries, derived from the surface temperature difference across the frame. Figure D.4 - Uf0 -values for metal frames with thermal break
The thermal resistance of the frame, Rf, is given by 1 0,17 Rf U f0
(D.1)
and the thermal transmittance of the frame, Uf, from Uf
1 Rsi Af, i / Ad, i Rf
Rse Af, e / Ad, e
(D.2)
Page 24 EN ISO 10077-1:2000 where Ad,i, Ad,e, Af,i, Af,e, are the areas as defined in clause 4, expressed in square metres; 2 Rsi is the appropriate internal surface resistance of the frame, in m K/W; 2 Rse is the appropriate external surface resistance of the frame, in m K/W; 2 Rf is the thermal resistance of the frame section, in m K/W, resulting from the thermal transmittance of the frame taking into account the appropriate surface resistance. 2 Uf0 is the thermal transmittance, in W/(m K), calculated as if the developed area were equal to the projected area.
Thermal conductivity of thermal break materials 0,2 < 0,3 W/(mK)
d
b1
b2
d
b3
d is the smallest distance between opposite aluminium sections of the thermal break; bj is the width of thermal break j; bf is the width of the frame.
b
b4
j
0,2bf
j
bf Figure D.5 - Section Type 1: Thermal break with a thermal conductivity below 0,3 W/(mK)
Thermal conductivity of thermal break materials 0,1 < 0,2 W/(mK)
d
b1
d
b2
d is the smallest distance between opposite aluminium sections of the thermal break; bj is the width of thermal break j; bf is the width of the frame.
b
j
0,3bf
j
bf Figure D.6 - Section Type 2: Thermal break with a thermal conductivity below 0,2 W/(m·K)
If the thermal conductivity of the termal break material is below 0,1 W/(m.K), the definition in figure D.6 is not valid.
Page 25 EN ISO 10077-1:2000
Annex E (informative) Linear thermal transmittance of frame/glazing junction The thermal transmittance of the glazing, Ug, 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. On the other hand, the thermal transmittance of the frame, Uf, is applicable in the absence of the glazing. The linear thermal transmittance describes the additional heat conduction due to the interaction between frame, glazing and spacer. The linear transmittance is mainly effected by the conductivity of the spacer material. For aluminium and steel (not stainless steel) glass spacers table E.1 indicates the values of for a specific range of types of frames and glazing.
Table E.1 - Values of the linear thermal transmittance,
2)
, for aluminium and steel (not stainless
steel) glass spacers Frame material
Wood frame and
Double or triple glazing,
Double glazing with low emissivity,
uncoated glass,
triple glazing with two low emissivity
air or gas space
coatings, air or gas space
W/(m·K)
W/(m·K)
0,04
0,06
0,06
0,08
0
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.
2)
2
These values are evaluated for double glazings with low emissivity, Ug 1,3 W/(m K) and triple 2 glazing with low emissivity Ug 0,7 W/(m K).
Page 26 EN ISO 10077-1:2000
Annex F (informative) Thermal transmittance of windows Table F.1 and table F.2 give typical values calculated by the method in this standard using linear thermal transmittances from annex E. Values for windows with other frame area fractions can be evaluated by means of the equations of the main part of that standard. Table F.1 - 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
1,0
1,4
1,8
2,2
2,6
3,0
3,4
3,8
7,0
5,7
4,3
4,4
4,5
4,6
4,8
4,9
5,0
5,1
6,1
3,3
2,7
2,8
2,9
3,1
3,2
3,4
3,5
3,6
4,4
3,1
2,6
2,7
2,8
2,9
3,1
3,2
3,3
3,5
4,3
2,9
2,4
2,5
2,7
2,8
3,0
3,1
3,2
3,3
4,1
2,7
2,3
2,4
2,5
2,6
2,8
2,9
3,1
3,2
4,0
2,5
2,2
2,3
2,4
2,6
2,7
2,8
3,0
3,1
3,9
2,3
2,1
2,2
2,3
2,4
2,6
2,7
2,8
2,9
3,8
2,1
1,9
2,0
2,2
2,3
2,4
2,6
2,7
2,8
3,6
1,9
1,8
1,9
2,0
2,1
2,3
2,4
2,5
2,7
3,5
1,7
1,6
1,8
1,9
2,0
2,2
2,3
2,4
2,5
3,3
1,5
1,5
1,6
1,7
1,9
2,0
2,1
2,3
2,4
3,2
1,3
1,4
1,5
1,6
1,7
1,9
2,0
2,1
2,2
3,1
1,1
1,2
1,3
1,5
1,6
1,7
1,9
2,0
2,1
2,9
2,3
2,0
2,1
2,2
2,4
2,5
2,7
2,8
2,9
3,7
2,1
1,9
2,0
2,1
2,2
2,4
2,5
2,6
2,8
3,6
1,9
1,7
1,8
2,0
2,1
2,3
2,4
2,5
2,6
3,4
1,7
1,6
1,7
1,8
1,9
2,1
2,2
2,4
2,5
3,3
1,5
1,5
1,6
1,7
1,9
2,0
2,1
2,3
2,4
3,2
1,3
1,4
1,5
1,6
1,7
1,9
2,0
2,1
2,2
3,1
1,1
1,2
1,3
1,5
1,6
1,7
1,9
2,0
2,1
2,9
0,9
1,1
1,2
1,3
1,4
1,6
1,7
1,8
2,0
2,8
0,7
0,9
1,1
1,2
1,3
1,5
1,6
1,7
1,8
2,6
0,5
0,8
0,9
1,0
1,2
1,3
1,4
1,6
1,7
2,5
NOTE The calculation has been made using -values according to annex E. 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.
Page 27 EN ISO 10077-1:2000
Table F.2 - 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
1,0
1,4
1,8
2,2
2,6
3,0
3,4
3,8
70
5,7
4,8
4,8
4,9
5,0
5,1
5,2
5,2
5,3
5,9
3,3
2,9
3,0
3,1
3,2
3,3
3,4
3,4
3,5
4,0
3,1
2,8
2,8
2,9
3,0
3,1
3,2
3,3
3,4
3,9
2,9
2,6
2,7
2,8
2,8
3,0
3,0
3,1
3,2
3,7
2,7
2,4
2,5
2,6
2,7
2,8
2,9
3,0
3,0
3,6
2,5
2,3
2,4
2,5
2,6
2,7
2,7
2,8
2,9
3,4
2,3
2,1
2,2
2,3
2,4
2,5
2,6
2,7
2,7
3,3
2,1
2,0
2,1
2,2
2,2
2,3
2,4
2,5
2,6
3,1
1,9
1,8
1,9
2,0
2,1
2,2
2,3
2,3
2,4
3,0
1,7
1,7
1,8
1,8
1,9
2,0
2,1
2,2
2,3
2,8
1,5
1,5
1,6
1,7
1,8
1,9
1,9
2,0
2,1
2,6
1,3
1,4
1,4
1,5
1,6
1,7
1,8
1,9
2,0
2,5
1,1
1,2
1,3
1,4
1,4
1,5
1,6
1,7
1,8
2,3
2,3
2,1
2,2
2,3
2,4
2,5
2,6
2,6
2,7
3,2
2,1
2,0
2,0
2,1
2,2
2,3
2,4
2,5
2,6
3,1
1,9
1,8
1,9
2,0
2,0
2,2
2,2
2,3
2,4
2,9
1,7
1,6
1,7
1,8
1,9
2,0
2,1
2,2
2,2
2,8
1,5
1,5
1,6
1,7
1,8
1,9
1,9
2,0
2,1
2,6
1,3
1,4
1,4
1,5
1,6
1,7
1,8
1,9
2,0
2,5
1,1
1,2
1,3
1,4
1,4
1,5
1,6
1,7
1,8
2,3
0,9
1,0
1,1
1,2
1,3
1,4
1,5
1,6
1,6
2,2
0,7
0,9
1,0
1,0
1,1
1,2
1,3
1,4
1,5
2,0
0,5
0,7
0,8
0,9
1,0
1,1
1,2
1,2
1,3
1,8
NOTE The calculation has been made using -values according to annex E. 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.
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, Rsh, is known (by calculation or by measurement) the additional thermal resistance, R, should be obtained using the appropriate expression in 5.3. Table G.1 gives some typical values of shutter thermal resistance and the corresponding values of R, which can be used in the absence of values of Rsh obtained from measurement or calculation. Table G.1 - Additional thermal resistance, R, 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 0,01 0,09 0,12 aluminium Roller shutters of wood and plastic 0,10 0,12 0,16 without foam filling Roller shutters of plastic with foam 0,15 0,13 0,19 filling Shutters of wood, 25 mm to 30 mm 0,20 0,14 0,22 thickness 1) The definition of the air permeability of shutters is given in annex H.
Low air permeability 0,15
0,22
0,26
0,30
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.
b sh b1 b 2 b 3
(H.1)
where b1, b2 and b3 are the average edge gaps at the bottom, top and side on the shutter (see figure H.1). b3 is included for one side only, since gaps at the side influence the permeability less than the gaps at the top and bottom.
b2 b2 external
b3 shutter
b1 b1
internal
external
b3
Figure H.1 - Definition of edge gaps
internal
Page 30 EN ISO 10077-1:2000 Table H.1 - 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, there should be no openings within the shutter itself. 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, respectively. The gap at the top is considered equal to 0 if the entrance to the roller shutter box is fitted with lips - 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. b) Other shutters Effective presence of strip gaskets on three sides and the gap at the fourth side less than 3 mm.
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 31 EN ISO 10077-1:2000
Annex ZA (informative) A-deviations A-deviation: National deviation due to regulations, 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. In the relevant CEN/CENELEC countries these A-deviations are valid instead of the provisions of the European Standard until they have been removed. Clause 6
Deviation Germany: Verordnung über einen energiesparenden Wärmeschutz bei Gebäuden (Wärmeschutzverordnung WärmeschutzV) Vom 16. August 1994. 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.
BS EN ISO 10077-1:2000
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