RT journal article
T1 Effect of Sky Discretization for Shading Device Calculation on Building Energy Performance Simulations
A1 Rodríguez Maestre, Ismael
A1 Foncubierta Blázquez, Juan Luis
A1 González Gallero, Francisco Javier
A1 Mena Baladés, Jesús Daniel
A2 Física Aplicada
A2 Ingeniería Industrial e Ingeniería Civil
A2 Máquinas y Motores Térmicos
K1 shading calculations; sky discretization; building energy simulation
K1 shading calculations
K1 sky discretization
K1 building energy simulation
AB The calculation of sunlit surfaces in a building has always been a relevant aspect in building energy simulation programs. Due to the high computational cost, some programs use algorithms for shading calculation for certain solar positions after discretization of hemispherical sky. The influence of the level of discretization on the estimation of incident direct radiation on building surfaces, as well as on the required computational times, are studied in this work. The direct solar energy on a window for a year, with simulation time steps of five minutes, has been simulated by using an algorithm based on Projection and Clipping Methods. A total of 6144 simulations have been carried out, varying window sizes, window orientations, typologies of shading devices, latitudes and discretization levels of the hemispherical sky. In terms of annual incident solar energy, the results show that maximum error values are about 5% for a low level of angular discretization. Errors up to 22% in hourly incident solar energy have been estimated for some of the configurations analysed. Furthermore, a great number of configurations show errors of shading factor on a window of up to 30%, which could be most relevant in studies of natural lighting. The study also shows that the improvement achieved by the most accurate discretization level implies an increase in computational cost of about 30 times.
PB MDPI
SN 1996-1073
YR 2020
FD 2020-03
LK http://hdl.handle.net/10498/23055
UL http://hdl.handle.net/10498/23055
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 21-sep-2026