IBPSA2009

A large variety of simulation environments exists for building and system simulation. Collaborative work is sometimes time-consuming since, in the different steps of building and system conception and optimization, different tools have to be used, each of them specifically dedicated to a particular problem: for example the overall conception of a building can be done using the TRNSYS simulation environment, while optimization of control strategies is likely to be done using the Matlab/Simulink simulation environment.

In a recent building simulation project, the significant effort required to calculate and enter casual gains and air flow data into the ESP-r modelling software was found to impede progress and increase the risk of error. A software tool, implemented as a Microsoft Excel spreadsheet using VBA, has been developed that avoids these problems by generating the required ESP-r data files automatically. The use of the spreadsheet had a major impact on project progress.

This paper presents a simple tool (in the form of nomograms) for the preliminary design of solar gains of a window shaded with a horizontal overhang. The nomograms were based on the results obtained from the previously published, experimentally validated anisotropic model of shaded window solar gains and developed using the least squares method. The nomograms were verified using the Design Builder (ver. 1.2) simulation software. The numerical simulations corroborated the relationship between window and shading system dimensions and solar gain reduction in the room.

Aiming to study the temperature field changes, the House VI project was checked. This house is located in Vila37, Rio de Janeiro, Brazil, a dead-end small street with only one inlet/outlet. In the houses of Vila37, the indoor ventilation is restricted to the facade windows. Giving the impossibility of introducing cross-ventilation in a traditional way, a short wind-catch was previously added with positive results; therefore, simulations with long wind-catch are being carried out.

The dynamic building simulation software IDA Indoor Climate and Energy v. 4.0 offers a standard level with fast input for general simulation projects, an advanced level for more flexible modelling, and a developer’s level with open code and editable models for specific problems. This enables that numerical investigations of non-standard systems within a whole-building context can be achieved at low costs. This paper presents three real case applications performed in the scope of a consultancy service. 

In winter, when the external air temperature is below zero, there is a risk of damage to coils in a closed type cooling tower due to freezing of cooling water. In warm climates, a method of draining cooling water from the coil can not be adopted to prevent freezing because a cooling load exists even in winter. It is necessary to make warm water circulate through the coil in closed type cooling tower. In this case, it isn’t clear when to operate an electric heater and a circulating warm water pump.

The presented paper reports on the application of a method for the numerical prediction of temperatures within and around structural passive cooling components. The recently developed method named the three-dimensional numerical generation of response factors NGRF (Zoras et al., 2009) was claimed to be fast, accurate and flexible as a result of incorporating elements of the response factor method into a finite volume technique based numerical model. Initially, a ‘pre-processing’ procedure is required to generate a certain number of hours, e.g.

In building simulation tools differential equations are widely used to model physical phenomena of components such as walls, air and any kind of system component in the building. Especially when simulation is used to study and optimise system control, the models used are mainly transient models solving differential equations in order to represent correctly the transient behaviour of the whole control loop. The TRNSYS simulation environment is a powerful tool allowing the simulation of a large number of problems.

This paper deals with the evaluation of different simulation approaches to kitchen ventilation modelling. Multi-zone, CFD and zonal approach are discussed.  The investigation moves its steps from the analysis of a controlled ventilation system intended for individual and collective housing. The question of natural ventilation being able of ensuring ventilation rates consistent with acceptable indoor air quality is dealt with. Buildings have become increasingly airproof and natural ventilation, as it will be presented, may result inadequate.