EN 13363-2:2005

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.GDSonnenschutzeinrichtungen in Kombination mit Verglasungen - Berechnung der Solarstrahlung und des Lichttransmissionsgrades - Teil 2: Detailliertes BerechnungsverfahrenDispositifs de protection solaire combinés a des vitrages - Calcul du facteur de transmission solaire et lumineuse -
Partie 2: Méthode de calcul détailléeSolar protection devices combined with glazing - Calculation of total solar energy transmittance and light transmittance - Part 2: Detailed calculation method91.120.10Toplotna izolacija stavbThermal insulation17.180.20Barve in merjenje svetlobeColours and measurement of lightICS:Ta slovenski standard je istoveten z:EN 13363-2:2005SIST EN 13363-2:2005en01-julij-2005SIST EN 13363-2:2005SLOVENSKI
STANDARD
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 13363-2April 2005ICS 17.180.20; 91.120.10English versionSolar protection devices combined with glazing - Calculation oftotal solar energy transmittance and light transmittance - Part 2:Detailed calculation methodDispositifs de protection solaire combinés à des vitrages -Calcul du facteur de transmission solaire et lumineuse - Partie 2: Méthode de calcul détailléeSonnenschutzeinrichtungen in Kombination mitVerglasungen - Berechnung der Solarstrahlung und desLichttransmissionsgrades - Teil 2: DetailliertesBerechnungsverfahrenThis European Standard was approved by CEN on 24 February 2005.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards 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 translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2005 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 13363-2:2005: ESIST EN 13363-2:2005

Determination of equivalent solar and light optical characteristics for louvres or venetian blinds.16 A.1 Assumptions.16 A.2 Symbols.16 A.3 Direct radiation.17 A.4 Diffuse radiation.17 A.5 Thermal radiation.17 A.6 Global radiation.17 A.7 Example.18 Annex B (normative)
Stack effect.19 B.1 General.19 B.2 Pressure loss factors.20 Annex C (informative)
Example.22 C.1 Input data.22 C.2 Results.22 Annex D (informative)
Physical properties of gases.23 Bibliography.24
3 µm to 100 µm NOTE 1 The definition deviates from EN ISO 9288. NOTE 2 Sometimes called longwave radiation, see EN ISO 9488. 3.1.3 total solar energy transmittance total transmitted fraction of the incident solar radiation consisting of direct transmitted solar radiation and the part of the absorbed solar radiation transferred by convection and thermal radiation to the internal environment 3.1.4 light transmittance transmitted fraction of the incident solar radiation in the visible part of the solar spectrum, see EN 410 3.1.5 normalized radiant flow rate radiant flow rate divided by the incident radiant flow rate 3.2 Symbols and units The following list includes the principal symbols used. Other symbols are defined where they are used in the text. Symbol Physical quantity Unit ES incident solar radiation flow rate, solar irradiation W/m² I normalised radiant flow rate − H height of a ventilated space m T thermodynamic temperature K U thermal transmittance
W/(m²⋅K) g total solar energy transmittance (solar factor) − h heat transfer coefficient, or thermal conductance of gas space W/(m²⋅K) q density of heat flow rate W/m² s width of a space m z vertical coordinate m ε thermal emissivity − α absorptance − αe solar direct absorptance − λ thermal conductivity W/(m⋅K) λ wavelength µm ρ reflectance of the side facing the incident radiation − ρ' reflectance of the side facing away from the incident radiation − ρe solar direct reflectance − ρv light reflectance − σ Stefan-Boltzmann constant 5,67×10-8 W/(m²⋅K4) τe solar direct transmittance − SIST EN 13363-2:2005

Subscripts a absorbed c conductive/convective d diffuse e external environment g gas i internal environment j, k integer, number of layer or space r radiant th thermal radiation v ventilated B blind D direct 4 Characteristic data 4.1 Solid layers The glass panes and blinds are considered as solid layers. The relevant characteristics are: • for solar radiation and light: the spectral transmittance and the spectral reflectances of both sides; • for thermal radiation: the transmittance and the emissivities of both sides. Usually, these values are determined directly by the most appropriate optical method1). For glazing, see the procedures recommended for glazing materials in EN 410. However, for louvres or venetian blinds, Annex A gives a method to calculate equivalent values based on similarly determined material properties. 4.2 Gas spaces The thermal properties of closed spaces filled with air or gas shall be calculated in accordance with EN 673. The spaces are described by their width and the physical properties of the gas (see Annex D, Table D.1). Ventilated air spaces are described by the width and the height of the space and the physical properties of the air. 5 Principles of calculation 5.1 General The combination of glazing and solar protection devices consists of a series of solid layers separated by air or gas filled spaces. The solid layers are assumed to be homogeneous with a negligible thermal resistance. The transport of solar radiation and heat is considered to be one-dimensional, except for ventilated spaces, where the two-dimensional convection is reduced to a one-dimensional formula.
1) See CIE Technical Report – CIE 130-1998 "Practical Methods for the measurement of reflectance and transmittance". SIST EN 13363-2:2005

Key Te external air temperature
1 external 7 internal Tre external radiant temperature
2 layer 1 8 solar radiation ve external wind velocity
3 space 1 9 direct solar and light transmittance Ti internal air temperature
4 layer j 10 direct solar and light reflectance Tri internal radiant temperature 5 space j 11 thermal radiation and convection
6 layer n
(direct and indirect)
NOTE The internal and external environments are characterised by the air temperature and the radiant temperature; the external environment is additionally characterised by the wind velocity. Figure 1 — Schematic presentation of a system consisting of layers and spaces 5.2 Solar radiation and light The solar and optical properties are independent of the intensity of the solar irradiation and temperature in the system2). It is assumed that the spaces are completely transparent, without any absorption. Each solid layer is characterised by the spectral transmittance and reflectance in the wavelength region between 0,3 µm and 2,5 µm. For each wavelength λ and each layer j the following equations are valid for the normalised radiant flow rates I and I' (see Figure 2): )()()()()()()()()()(111λλτλλρλλλρλλτλjjjjjjjjjjIIIIII′⋅′+⋅=′′⋅′+⋅=−−− (1) where
2) There are exceptions for certain materials (photochromic, thermochromic). SIST EN 13363-2:2005

is the spectral normalised radiant flow rate inwards; I'j(λ) is the spectral normalised radiant flow rate outwards.
Figure 2 — Schematic presentation of the characteristic data of layer j and the spectral flow rates
Equation (1) is solved with the boundary conditions: 0)(;1)(0=′=λλnII (2)
If the spectral normalised radiant flow rates )(λjI and )(λjI′ are known for each j, the spectral data of the system result in: the spectral transmittance: )()(λλτnI= (3) the spectral reflectance of the side facing the incident radiation: )()(0λλρI′= (4) the spectral absorptance of layer j: ()())()()(1)()()(1)(1λλτλρλλτλρλαjjjjjjjII′⋅′−′−+⋅−−=− (5) The solar direct transmittance eτ, the solar direct reflectance eρ and the solar direct absorptance je,α of each layer j shall be calculated from the spectral data according to the procedure given in EN 410. Similarly, the light transmittance vτ and the light reflectance vρ can be calculated. If the spectral reflectance)('λρof the sy
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