**2. Overview of the proposed numerical simulation modelling**

TRNSYS and TRNFlow programmes are selected for carrying out the proposed numerical modelling, which are able to predict the effects of the implementation of the BIPV-DSF on building performance such as energy consumption and indoor thermal condition, based on the capabilities of the software. TRNSYS is a graphically based software, which has been validated and widely used in the BIPV and building related research activities [5–8]. In addition, TRNSYS output data files are in a (human) readable and editable plain text format, which allows users to convert dataset simulation results to Excel spreadsheet; hence, they precisely present the result plots and effectively observe the errors of simulations. Energy consumption of thermal building models and electricity productions of the BIPV

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sequence:

the DSF.

*Numerical Simulation Modelling of Building-Integrated Photovoltaic Double-Skin Facades*

systems can be directly predicted in TRNSYS. TRNFlow is an external engine for TRNSYS for assisting in the calculation of ventilation [9], which can be integrated into the TRNSYS thermal building model (Type56) to analyse the performance of ventilation within the DSF and therefore the indoor thermal comfort due to the

TRNSYS was initially developed by the University of Wisconsin and the latest programme and external plugins of the software are the outcomes of international collaboration of the US, France and Germany [10]. TRNSYS and its plugins can be used for functions, such as electric power simulation, solar design, building thermal performance analysis, HVAC system sizing as well as airflow analysis [10]. TRNSYS provides a modular structure for simulating the transient systems, especially energy systems, such as solar systems (PV systems) and HVAC systems [11]. The simulation activities in this chapter are demonstrated by using the version of TRNSYS 17.

• TRNSYS Simulation Studio (**Figure 2**) – a visual interface used for model design, parametrisation and system simulation. Type 56 (the "Building" icon in **Figure 2**) includes the details of a multi-zone building model such as building geometry, load profiles, construction and window glazing properties, while the desired weather file can be uploaded in the "Weather data" component

• TRNDII – a simulation engine of TRNSYS which is called by TRNEXE

• TRNBuild (as shown in **Figure 3**) – a visual interface used for creating and editing the simulation input data for non-geometry information of the

• TRNEdit or TRNSED – an editor programme that to create stand-alone

In general, TRNSYS Simulation Studio in association with TRNBuild are used to assess energy performance of the proposed BIPV-DSF building model. In addition, as mentioned earlier, an external plugin, namely TRNFlow (as shown in **Figure 4**), is chosen for the integration with the TRNSYS thermal building model, in order to assess the performance of ventilation (for example, natural ventilation) within

In the Simulation Studio interface (as shown in **Figure 5**), Type 56-TRNFlow (the green "Building" icon) contains the specific numerical information of the multi-zone building model, which is not only including building geometry, load profiles, construction and window glazing properties, but also including the airflow

The functionalities of those programmes of TRNSYS are implemented by using

input and output values for the purpose of the simulation of ventilation.

the common computer programming languages for instance "Fortran", which establishes mathematical models for the components and types (in TRNSYS) of the proposed systems in terms of their ordinary differential or algebraic Equations [12]. The general procedures of the simulation modelling in TRNSYS are as follows, in

*DOI: http://dx.doi.org/10.5772/intechopen.97171*

**3. Building simulation modelling in TRNSYS**

The main programmes of TRNSYS 17 [11] include:

ventilated DSF.

(**Figure 2**).

(an executable program).

multi-zone buildings.

applications for proposed models.

*Numerical Simulation Modelling of Building-Integrated Photovoltaic Double-Skin Facades DOI: http://dx.doi.org/10.5772/intechopen.97171*

systems can be directly predicted in TRNSYS. TRNFlow is an external engine for TRNSYS for assisting in the calculation of ventilation [9], which can be integrated into the TRNSYS thermal building model (Type56) to analyse the performance of ventilation within the DSF and therefore the indoor thermal comfort due to the ventilated DSF.
