Dynamic thermal circuit modelling with distribution of internal solar radiation on varying façade orientations

Abstract

This paper aims at introducing an improved methodology for the dynamic modelling of buildings by the thermal networks method. This methodology employs, as a tool, the commonly used ASHRAE clear sky model to allow for the calculation of the external façade radiation and the distribution of the penetrating solar flux on the internal surface-nodes of the zone. The zone considered has an entirely glazed façade with a varying type of glazing and its enclosure is a rectangle parallelipipedic. The incident solar radiation is determined for building surface azimuths ranging from east to west in 45° step increments. The mathematical formulation of this solar-angle dependent lumped capacitance thermal model is based on the nodal approach and is updated in 15min time increments. The proposed methodology provides more insight to help understand the impact of opaque and glazed façade orientations and layer-formation on energy consumption. Results from annual energy performance calculations vs glazed-façade orientation, for various glazing systems, are given for a building zone location in the Mediterranean region. Depending on the building façade orientation and climatic conditions, proper selection of the type of glazing can reduce the annual building energy consumption.