Why ALMABuild?

Why can ALMABuild be a valid alternative to the most diffuse commercial codes?

ALMABuild is an open library of Simulink components. Each user can modify and add new blocks. In this way the user knows exactly what he is doing and how he can ask to the building model for useful outputs.

Must users be expert in Simulink?

The knowledge of MATLAB is a pre-requisite. The users who know MATLAB and Simulink can modify each block of the ALMABuild library and introduce new components for specific cases. However, if the user is not able to work directly with Simulink, the Simulink model is created automatically by ALMABuild!

Generally, Whole Building Energy Simulation (WBES) tools do not allow a detailed prediction of comfort conditions, since the complete control of the local indoor conditions of a thermal zone needs a detailed reconstruction of the spatial distribution of humidity ratio, radiant temperature and air velocity, among other parameters. To obtain this goal, a complete Computational Fluid Dynamics (CFD) simulation is generally needed, with an increase of the computational cost of the whole simulation, which is obtained by coupling CFD and WBES by introducing the “co-simulation” concept.

May I avoid co-simulation?

Co-simulation means a model in which two or more software platforms are combined together with the aim to obtain detailed information about the observed system. Co-simulation is used also for solving multi-objective optimization problems; in fact, WBES tool in some cases is not directly able to use optimization algorithms, so the multi-objective optimization is obtained by using a specific external software in order to drive the WBES tool through the process: by means of optimization algorithms implemented in the dedicated software, input data of dynamic simulations performed with WBES tool can be iteratively modified, until optimal solutions are found.
The features of MATLAB/Simulink, as framework for developing new WBES tools, can overcome the limitations of many available WBES tools, reducing the use of complex co-simulations for the detailed evaluation of indoor comfort conditions and for solving multi-objective optimization problems. In particular, the possibility to use all the MATLAB toolboxes for solving problems concerning different issues (e.g. optimization, CFD…) in a single computational environment, avoiding the need of coupling different software packages as well as the possibility to adopt a variable time step discretization for simulations are some of the most attractive features of MATLAB for the development of new WBES tools. This aspect can enlarge the number of users having the skills for the management of the sophisticated dynamic simulations since only the use of a unique tool operating in MATLAB is needed.

Is open-source better?

ALMABuild forced the author to a deep and critical investigation of all the mechanisms which are involved in building physics. This investigation was not possible by using commercial codes because in these cases the user is able to understand only partially in which way the tool is able to model a specific aspect of the building physics. Finally, an important goal achieved by ALMABuild is the simplification of the building modelling in Simulink. The adoption of specific GUIs for the data insertion and the automatic implementation of the building modelling, thanks to a series of m-files, enable to overcome the main drawback which is responsible of the limited diffusion of similar Simulink-based tools (see SIMBAD, HAMBASE, CARNOT and IBPT among others).