Pitfalls in Weather Data Management Strategies of Building Performance Simulation Tools

The use of simulation for building design and performance assessment is becoming mandatory if NZEB requirements have to be met. As a matter of fact, only dynamic simulations are able to correctly account for renewable energy exploitation on the building site. Dealing with solar energy source conversion, the correct use of available standard weather data files is still more important than solar gains through the transparent envelope. When using such statistically derived weather data, however, different pitfalls might arise. In fact, when performing sub-hourly simulation, the information provided by hourly-based climatic data is insufficient. Interpolation algorithms are implemented in Building Performance Simulation tools (BPSts) to provide intermediate weather data, which can affect the quality of the results. Specifically, solar radiation data are insufficiently represented by hourly-based values when dealing with short time-step simulations of complex building systems. In this article, a review of radiation algorithms and weather data management algorithms at sub-hourly simulation time steps will be introduced, as implemented by two well-known software, such as TRNSYS 17 and EnergyPlus 8.6.0. Further considerations will be made upon information exchange among simulation components during the simulation, and upon the possibilities offered or denied by different data management-implementations when multiple actors are involved in the simulation.