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Simulation of fire exposed structures. Validation of the programs BISTRA & VOLTRA according to the EUROCODES (EN 1992-1-2:2004)
EN 1992-1-2: 2004 Annex A contains a 2D test reference case for validating transient simulation programs in case of fire exposed structures. A concrete column (h x b = 300 mm x 160 mm) is exposed to fire conditions. The case is simulated using the programs BISTRA and VOLTRA.
keywords: BISTRA, VOLTRA, EN 1992-1-2:2004, fire, dynamic, concretemore info
Bisco validation EN ISO 11855-2 floor heating
EN 15377 Annex D of the standard EN ISO 11855-2:2015 contains a test example that must be used to verify a steady state numerical calculation program. The program BISCO is used to simulate the test example.
keywords: BISCO, EN ISO 11855-2, floor heating, validation, standardmore info
Simulation of frame cavity heat transfer using BISCO v10w & BISCO v11w
In window frames, the heat transfer through air cavities is often a quite important part of the global heat transfer through them. This paper discusses how heat transfer through air cavities is treated in BISCO in line with EN 10077-2.
keywords: BISCO, RADCON, EN 10077-2, window frame, cavity heat transfermore info
Exercise junction roof wall
In this exercise a dxf file is imported in BISCO to calculate the linear thermal transmittance of a roof-wall junction. The geometry is then imported in TRISCO to carry out the same calculation in 3D (in line with EN 10211).
Keywords: BISCO, TRISCO, EN 10211, dxf to BISCO, BISCO to TRISCO, linear thermal transmittancemore info
3D & 2D Simulation of fixings – validation of EN 12631:2017 ANNEX E
Annex E of the standard ISO 12631:2017 contains a smoothed λ method to include the thermal effect of fixings in 2D numerical calculations. It is implemented in BISCO and the results are compared to a realistic 3D simulation in SOLIDO and to other alternative methods in BISCO and TRISCO.
Keywords: BISCO, TRISCO, SOLIDO, screws, 2D numerical method, EN 12631–Annex Emore info
Calculation of the linear thermal transmittance of a glazing spacer using the program BISCO
The calculation of the linear thermal transmittance of a glazing spacer according to EN ISO 10077-2 requires two BISCO simulations. A first one, with an insulation panel instead of the glazing, results in the thermal transmittance of the frame. From this value and from a second simulation, with a specific glazing, the linear thermal transmittance of the glazing spacer can be derived.
Keywords: BISCO, spacer, EN ISO 10077-2more info
Simulation of internal surface corner heat transfer using the RADCON module
According to standard 10077-2, reduced heat transfer coefficients should be applied at internal corners. As an alternative, the use of the type BC_SKY (RADCON module) in BISCO allows a rather correct physical simulation of the surface heat transfer by radiation and convection. In this document both methods are implemented and compared for 4 cases.
Keywords: BISCO, internal corner, heat transfer coefficient, EN 10077-2, EN 6946more info
Thermal simulation of non-ventilated cavities using the RADCON module
This document discusses the methods described in various standards for the non-ventilated cavities thermal simulations and their implementation in the Physibel software. This includes the λeq and the radiosity methods of EN 10077-2, with both linear and non-linear radiation models.
Keywords: BISCO, TRISCO, non-ventilated cavities, EN 10077-2, EN 6946, EN 673more info
Program TRISCO – Node temperature postprocessor
A postprocessor spreadsheet tool is discussed in this document. It allows reporting the node temperatures at selected grid positions.
Keywords: TRISCO, node temperature, spreadsheet toolmore info
Program TRISCO – Variable parameter analysis
A postprocessor spreadsheet tool for a variable parameter analysis using TRISCO is discussed in this document. An example is given to obtain the linear thermal transmittance of a roof edge as a function of the thermal conductivity of the thermal break material.
Keywords: TRISCO, variable parameter analysis, spreadsheet toolmore info
Validation of the programs TRISCO & SOLIDO according to ISO 10211
Annex C of the standard ISO 10211 contains 4 test reference cases (2 2D and 2 3D) that must be used in order to be classified as a three-dimensional steady-state high precision method. The programs TRISCO and SOLIDO are used to simulate the 4 test examples.
Keywords: TRISCO, SOLIDO, validation, standards, EN ISO 10211more info
This document includes 5 exercises of TRISCO simulations: Cladding fixed with brackets; Brick wall; Brace; Exercise Pilotex from the manual and Junction roof-wall.
Keywords: TRISCO, 3D heat transfer, brackets, brick wall, brace, junction roof-wallmore info
Simulation of frame cavity heat transfer using BISCO v10w & BISCO v11w
The standard ISO 10077-2 allows two methods to be used for the calculation of the global heat transfer through cavities: the single equivalent thermal conductivity method and the radiosity method. The aim of the present document is to discuss and compare both methods for users of BISCO version 10w and 11w with examples of sample frame and detailed cavity simulations.
Keywords: BISCO, 2D heat transfer, frame cavity, equivalent lambda, radiosity method, EN ISO 10277-2more info
Validation of simplifying the thermal simulation of an object with a 3D sloped metal bar
Objects containing sloped metal bars can be simulated thermally using the Physibel program SOLIDO. Because of the sloped shape a dense grid is required for a precise thermal simulation. Therefore, when simulating complex details containing sloped metal bars, it is often of interest to make a rectangular simplification. A few simplification methods are validated.
Keywords: TRISCO, SOLIDO, sloped shape, rectangular simplificationmore info
Simulation of 2D heat transfer BISCO versus TRISCO
The program TRISCO is initially made to simulate block shaped 2D/3D objects the program BISCO is limited to 2D but allows objects with any shape. For rectangular 2D objects BISCO and TRISCO result in almost identical results. 2 examples are given that show that this is also valid for non-rectangular 2D objects on the condition that a surface heat transfer correction is applied.
Keywords: BISCO, TRISCO, 2D heat transfer, surface heat transfer, correctionmore info
Floor thermal transmittance and foundation linear transmittance
To calculate the thermal transmittance of a floor on ground Ug, EN 13370 allows several methods: a 3D numerical method, a 2D numerical method and a simplified method. To calculate the linear thermal transmittance of a wall/floor junction ψg only the 2D and the 3D numerical methods are applicable. A case study shows the use of these methods.
Keywords: BISCO, TRISCO, floor, foundation, EN 13370more info
Linear transmittance of an internal wall foundation
The heat flow through a thermal bridge caused by an internal wall foundation depends on the size of the building and on the location of the internal wall. Therefore it is relatively complex to derive the linear thermal transmittance of such foundation details. A 3D thermal simulation of the whole floor is required. A simplified method is proposed in this document and validated, using a case study.
Keywords: TRISCO, internal wall, foundation, thermal bridgemore info
Linear thermal transmittance of a wall-floor junction
The linear thermal transmittance of a wall-floor junction is calculated using the program TRISCO.
Keywords: TRISCO, wall floor junction, linear thermal transmittance, thermal bridgemore info
Linear and point thermal transmittance of thermal bridges
The linear thermal transmittance and the point thermal transmittance for an external wall containing both a linear thermal bridge and a point thermal bridge are calculated using the program TRISCO.
Keywords: TRISCO, linear thermal transmittance, point thermal transmittance, thermal bridgemore info
The linear transmittance of a ground floor – window sill construction detail
A procedure to calculate the linear thermal transmittance of a ground floor – window sill construction detail according to EN ISO 13370 is explained using a case study.
Keywords: BISCO, ground floor, window sill, linear thermal transmittance, EN 13370, EN 10211more info
Repeating thermal bridging
A massive brickwork wall is internally insulated. The thermal insulation is interrupted by a wooden stud at regular distances, causing a thermal bridge effect. This thermal bridge effect is quantified using the programs BISCO and TRISCO.
Keywords: BISCO, TRISCO, thermal bridge, repetition, thermal transmittancemore info
2D-3D Thermal evaluation of a roof junction
For a roof junction construction detail the linear thermal transmittance and the point thermal transmittance are derived, for both the internal and the external dimension system, using the programs BISCO and TRISCO. Also the 3D temperature course is derived allowing a surface condensation risk evaluation.
Keywords: BISCO, TRISCO, thermal bridge, roof junctionmore info
Linear thermal transmittance of a wooden frame corner
The calculation of the linear thermal transmittance of a wooden frame corner is discussed. This thermal bridge effect is quantified using the programs BISCO and TRISCO.
Keywords: BISCO, TRISCO, linear thermal transmittance, wooden frame, cornermore info
Thermal analysis of a wall-window junction
The thermal transmittance of a wall-window junction is calculated according to the applicable European standards. 2 approaches to analyse the problem are discussed: a 2D heat transmission calculation and a heat transmission calculation ‘by hand’.
Keywords: BISCO, TRISCO, wall window junction, EN 6946, EN 10077-2, EN 10211more info
Thermal analysis of the building envelope in summer conditions – part I: opaque constructions
The knowledge of the maximum temperature that can occur in the building envelope is often of interest to investigate damage risk. Such thermal analysis can be done using multiple Physibel programs. Increasing levels of accuracy, corresponding to a decreasing degree of simplification, can be applied, as shown in multiple case studies.
Keywords: BISCO, CAPSOL, BISTRA, envelope, summer, opaque, EN 13791, EN 13792, ISO 6946, EN 10077-2more info
Thermal analysis of the building envelope in summer conditions – part II: transparent constructions
The knowledge of the maximum temperature that can occur in the building envelope is often of interest to investigate damage risk. A case study shows how the program BISTRA is used to simulate the temperature course in a glazed façade during a sunny day.
Keywords: BISTRA, summer, glazed façade, ISO 10456, EN 673more info
2D&3D transient simulations using the solar processor
Multiple simulation examples, with growing complexity, explain the use of the program VOLTRA for simulating the 2D & 3D transient behaviour of a room with a double façade.
Keywords: VOLTRA, solar radiation, double façade, ventilated cavity ISO 10456, EN 673more info
Simulating 2D interstitial condensation using the program BISCO
BISCO is designed for simulating two-dimensional steady state heat transfer. However, as the governing mathematical equations for vapour diffusion are similar to the ones for heat transfer, the program can be used for simulating vapour diffusion as well. The document explains how to use BISCO to predict interstitial condensation in a construction detail.
Keywords: BISCO, condensation, vapour diffusion, vapour pressuremore info
Air cavity – Stack effect simulation
An empirical method is used to calculate the stack effect in an air cavity or in a room connected to an environment at a different temperature through an inlet and an outlet at different levels. The method is implemented in an Excel spreadsheet. An example is given on how to use the method in the program CAPSOL.
Keywords: CAPSOL, stack effect, cavity, spreadsheet, airflowmore info
The equivalent thermal conductivity of a perforated metal plate
The heat transfer through building components including perforated metal plates is 3D. If a 2D simulation is preferred or if the 3D component is relatively complex, it is helpful to replace the perforated plate by a homogeneous plate. A method for calculating the equivalent thermal conductivity of a perforated metal plate is explained and validated.
Keywords: BISCO, TRISCO, equivalent conductivity, 3D, 2D, ISO 10211more info
A phase-change material (PCM) stores and releases heat when melting and freezing, which occur at a given temperatures. The programs VOLTRA and BISTRA allow simulating the thermal behaviour of objects in which such PCM’s are embedded. As an example, the temperature course in 2 identical rooms, one without and one with PCM is simulated. 2 cases are discussed: a first one with a pure PCM, a second one with a board that is commercially available.
Keywords: VOLTRA, BISTRA, PCM, room temperaturemore info
Heat losses from a radiator to a glazed façade
The heat losses through an external wall behind a radiator are higher than the ones estimated by a standard wall heat loss calculation. This is mainly due to radiation. An example shows how to investigate the supplementary radiation heat loss and how to evaluate improvements such as radiation shields.
Keywords: BISCO, glazed façade, radiation, shielding, RADCON, EN 6946more info
Dealing with thin metallic layers in the program BISCO
The heat transfer through thin metallic layers can be simulated using the Physibel programs TRISCO and BISCO. Whereas thin layers are possible in TRISCO (through thin grid widths), the lowest layer thickness in BISCO is limited to the pixel size. A very small pixel size sometimes results in a too large bitmap due to a memory problem. An alternative approach for such cases is proposed. The method is validated for a plastic glazing spacer covered with a metallic layer.
Keywords: BISCO, thin layers, metallic, glazing spacermore info
Thermal simulation of vacuum glazing
Creating a vacuum layer between 2 glazing panes, of which one has a low emissivity coating, results theoretically in a glazing with a very low thermal transmittance, due to a very low heat transfer by conduction and radiation over the cavity. However, practically border and punctual spacers are required to maintain the vacuum. These spacers cause an additional 3D conduction heat transfer effect, increasing the thermal transmittance. The vacuum glazing is simulated in 3D using the program TRISCO with the RADCON module.
Keywords: TRISCO, vacuum glazing, spacers, RADCON, EN 673more info
BISCO – Sample window frames
A dozen of examples of BISCO simulation of window frames are given and detailed, including aluminium, wood, PVC and steel frames.
Keywords: BISCO, window frames, examplesmore info
Round-robin simulations of the ISO 10077-2 examples using the program BISCO v10
While the 2003 version of ISO 10077-2 defined an equivalent thermal conductivity to simulate radiation and convection or conduction through cavities, the 2017 version also includes a detailed radiation method. The annexes contain examples for the validation of calculation programs. In the framework of a round robin test BISCO version 10w is used to calculate these examples.
Keywords: BISCO, RR simulation, radiosity method, RADCON, ISO 10077-2more info
Validation of the program BISCO according to ISO 10211
Annex C of the standard ISO 10211 contains 2 two-dimensional test reference cases. In order to be classified as a two-dimensional steady-state high precision method, BISCO shall give results corresponding with those of these 2 cases.
Keywords: BISCO, standard examples, validation, ISO 10211more info
Clear sky radiation
Due to clear sky radiation the external building envelope surface temperature can be lower than the outdoors air temperature. A roof edge, in which a condensation problem occurred in early spring, is simulated both under steady state and transient conditions. The case studies show that the clear sky radiation causes the condensation problem.
Keywords: BISCO, clear sky, radiation, glazing, ventilated cavity, RADCONmore info
Thermal analysis of a floor heating system
For a floor heating system, the water temperature course and the floor temperature distribution are simulated using the transient programs BISTRA and VOLTRA, both in steady and transient state.
Keywords: BISTRA, VOLTRA, floor heating, cooling, inertiamore info
Efficiency of frost insulation to protect a foundation
A case study shows how the program BISTRA can be used to evaluate the efficiency of frost insulation protecting a foundation.
Keywords: BISTRA, VOLTRA, foundation, frost insulationmore info
Thermal simulation of reflective foils
When the material surfaces around a cavity have a low infrared emissivity, for example if they are covered by an aluminium foil, the radiation heat transfer is reduced. Using an example, it is shown how to deal with such reduced cavity heat transfer in the Physibel software.
Keywords: BISCO, TRISCO, reflective foils, radiation, RADCON, ISO 6946more info
Transient solar heat gains through a glazing with a solar shading
A method for calculating the effect of solar shading systems on the solar transmittance of a glazing is explained. The solar factor as defined in EN 410 is of little use for this purpose because it is defined for a solar radiation with a direct component that is perpendicular to the glazing. The programs BISTRA (2D) and VOLTRA (3D) contain a solar processor that takes the sun position into account and allow simulating a kind of transient solar factor.
Keywords: BISTRA, VOLTRA, glazing, shading, solar radiationmore info
Create STL with SketchUp for SOLIDO/TRISCO
The steps are described to create STL files with Sketchup and use them for SOLIDO or TRISCO: from the drawing to the importation of a STL file in TRISCO.
Keywords: SOLIDO, TRISCO, STL files, Google SketchUpmore info
Clear sky radiation visual validation
On a clear sky winter morning hoar-frost occurs at the external glazing surface of a garret-window. The case is simulated using the program TRISCO (with RADCON module).
Keywords: TRISCO, radiation, frost, glazing, visual validationmore info
Experimental validation of transient heat transfer simulation
The temperature evolution of a small barrel of hot water positioned in a room with almost constant temperature was measured and compared to the numerical simulation of the cooling process. 2 simulations were made, one using an analytical formula and another one using the program VOLTRA.
Keywords: VOLTRA, experimental validation, cooling process, transientmore info
Low emissivity visual validation
On a single glazing, condensation occurs more intensively behind a copper coffee pot. This is due to the low emissivity of the coffee-pot. A simulation using the program TRISCO (with RADCON module) results in a similar isotherm course as the condensation pattern.
Keywords: TRISCO, radiation, condensation, visual validationmore info
The thermal transmittance of masonry according to EN 1745
Some examples are given showing how to calculate the thermal transmittance of masonry according to the standard EN 1745. The examples were prepared using the programs BISCO, TRISCO and SOLIDO.
Keywords: BISCO, TRISCO, SOLIDO, masonry, EN 1745more info
2D-3D thermal evaluation of a roof junction
The heat loss through a thermal bridge between 2 environments (typically indoors and outdoors) can be described using a single linear thermal transmittance (ψ-value). For a thermal bridge between 3 environments at different temperatures (e.g. indoors, outdoors and attic), 3 ψ-values are required. The procedure from Annex E of EN ISO 10211, is applied for a sample thermal bridge.
Keywords: BISCO, thermal bridge, 3 environments, roof junction, ISO 10211more info
Thermal bridge surface condensation case study
On the internal surface of thermal bridges low temperatures occur in wintertime, causing a risk of surface condensation and mould growth. A 3D corner joining 2 façade walls and a flat roof is analysed as an example.
Keywords: TRISCO, thermal bridge, condensation, corner, mould growthmore info
Simulating ventilated double façades using the program BISCO or TRISCO
BISCO and TRISCO (with RADCON module) can be used to simulate ventilated double façades in steady state. The ventilation heat flow is replaced by an equivalent convective heat flow to a small pipe. The results are validated using the program VOLTRA.
Keywords: BISCO, TRISCO, VOLTRA, ventilated double façade, equivalent convective heat flowmore info
View factor calculation using the program TRISCO
View factors are used in the simulation of radiation heat transfer. In the Physibel 2D & 3D software the view factors are automatically calculated and implemented in the radiation equations (RADCON module). The explicit knowledge of the view factors is usually of little importance, but sometimes view factors values are needed for use in other applications, for example in the building simulation program CAPSOL. An example is given how view factor values can be derived from the program TRISCO.
Keywords: TRISCO, view factors, roommore info
Visual validation of 3D heat transfer
At first sight a visual validation of heat transfer seems to be a contradiction: only the infrared radiation and not the visual light emitted by surfaces is related to the temperature. However, as surface condensation is visual and depends on the surface temperature, a visual validation of heat transfer is possible by comparing the pattern of drying surface condensation to the simulated isotherms on the surface.
Keywords: VOLTRA, visual validation, condensation, drying pattern, transientmore info
Experimental validation of the program VOLTRA for 3D transient heat transfer
Two experimental validations of the program VOLTRA for simulating 3D transient heat transfer were done on a small glazed wooden box. In the first indoors experiment the transient heat transfer due to a sudden internal power source was investigated. In the second experiment the box was put outdoors, allowing validating the solar processor module in VOLTRA.
Keywords: VOLTRA, experimental validation, glazed box, solar processormore info
Validation of the programs BISCO and TRISCO according to EN 1745
Annex D of the standard EN 1745:2012 “Masonry and masonry products – Methods for determining thermal properties” contains 3 test reference cases (1 2D and 2 3D). The validations simulations are done using the programs BISCO and TRISCO.
Keywords: BISCO, TRISCO, EN 1745, masonrymore info