INTERNATIONAL. STANDARD. ISO. First edition. Thermal performance of windows, doors and shading devices — Detailed calculations. 5 Jan ET ISO Thermal performance of windows, doors and shading devices [ archiveorg width= height= The standard is identical with ISO Thermal performance of windows, doors and shading devices — Detailed calculations published by International.
|Published (Last):||23 December 2017|
|PDF File Size:||6.39 Mb|
|ePub File Size:||8.22 Mb|
|Price:||Free* [*Free Regsitration Required]|
ISOThermal insulation — Physical quantities and definitions ISOThermal insulation — Determination of steady-state thermal resistance and related properties — Heat flow meter apparatus ISOThermal insulation — Determination of steady-state thermal resistance and iso 15099 properties — Guarded hot plate apparatus ISOGlass in building — Determination of light transmittance, solar direct transmittance, total solar energy transmittance, ultraviolet transmittance and related glazing factors ISOThermal insulation — Heat transfer by radiation — Physical quantities and definitions ISOSolar energy — Reference solar spectral irradiance iso 15099 the ground at different receiving conditions — Part iso 15099 If the shortest distance between two opposite surfaces is smaller iso 15099 5 mm, then the frame cavity shall iso 15099 split at this “throat” region.
The emissivity of the iso 15099 surface is reduced by the factor given in Equation An appropriate value is to be determined on the basis of experiments or calculations [computational fluid dynamic CFD modelling].
Usually an emissometer is used for this purpose. In the sum of the spectral heat flows: The extra term is: These are the temperatures of the external and internal facing surfaces, T fti and T bj plus the radiant heat leaving the front and back facing surfaces i.
Quantity iso 15099 sc q sk is the prescribed density of heat flow rate at the boundary source or sink. Ethiopian Standards are approved by the National Standardization Council and are kept under continuous review after publication and updated regularly to take account of latest scientific and technological changes.
The effective conductivity of a given cavity shall be calculated using the results of the vision area analysis. The driving pressure difference Ap Iso 15099 may be written approximately as: The process described iso 15099 has to be solved for every wavelength band required by the properties of the elements or by the rest of the transparent system where the shading device is installed.
Due to the iso 15099 of non-specular reflection, a slight curving of the slats may be ignored. The standard is identical with ISO The characteristic iso 15099 of the temperature profile is defined by: Adjustments to the dimensions of the geometric model are allowed only if 51099 have no ixo influence on the calculation see ISO Calculate the effective conductivity of iso 15099 bridging elements e. NOTE For more information on the norm or root mean square values of the temperature vector, see .
The radiosity of surface iso 15099, Jj, is given by: The dimensions of all parts shall be the nominal values as given on the manufacturer’s drawings, provided that these drawings are an actual representation of the fenestration product.
Due to the air flow through the space, the air temperature in the space varies with height see Figure These total optical properties apply to wavelengths from 5 urn to 50 urn. Diffuse radiation transmitted or reflected by the solar shading device is assumed to remain diffuse.
ISO – Thermal performance of windows, doors and shading devices — Detailed calculations
The thermal transmittance of the fenestration product is given by: Selected examples of calculated optical properties of a slat type of shading device as function of the slat properties and geometries are given in Annex C. NOTE Iso 15099 information about r ft. iso 15099
This two-dimensional iso 15099 shall provide the rate of heat transfer through each unique frame section. The following rule shall be used see also Figure The least square linear curve fit equations were derived from thermophysical property iso 15099 given in Reference .
ET ISO 15099: Thermal performance of windows, doors and shading devices — Detailed calculations
The more stringent criterion, specified above, is now possible iso 15099 the iso 15099 of computing 150999. For dated references, only the edition cited applies. Each of these subclauses pertains to one particular value, or range, of tilt angle, y This categorization, as a function of y is based on the assumption that the cavity is heated from the internal side i.
NOTE For more information, see .
In’ terms of these variables, 9i is: The total properties are each based on total projected area occupied by the product, A t. NOTE This requirement is more stringent iso 15099 that specified 10599 ISOwhich requires iso 15099 the number of subdivisions be doubled until the change in heat flow through the object is reduced to a prescribed tolerance.
Beam radiation transmitted or reflected by the solar shading device is considered 10599 be split into two parts: The values of four variables are sought at each glazing. Complete windows and doors ENGlass in building — Determination iso 15099 the emissivity 3 Symbols 3. See national standards for the required cross sections to be considered. Heat is transferred by natural iso 15099 i.
If the view between two radiating surfaces is obstructed by a third surface, the effect of this obstruction shall be included. This iso 15099 that it is no longer sufficient to iso 15099, as in 5.
For an unventilated, iso 15099 shaped frame cavity, the geometry shall be converted into the equivalent of a rectangular cavity iso 15099 accordance with the procedure in ISO see also Figure Due to the redirection of the radiation, the forward transmittance is not necessarily equal to the backward transmittance, as illustrated in Figure For undated references, the latest edition of the iso 15099 document including any amendments applies.
The boundary conditions consist of: A where X is the thermal conductivity of air. In that case the equations given isso remain valid, iso 15099 “air” is replaced by “gas-mix”, with the corresponding gas-mix properties. Where national standards allow, test procedures may be used to determine component and total product properties.