Impact of Cladding Material and Air Cavity on Ventilated Facades in Warm Semi-Arid Climates

This study examines the high air conditioning demand characteristic of buildings located in warm semi-arid climates, where intense solar radiation and low humidity significantly increase thermal loads on the building envelope. In this context, ventilated facades have emerged as a promising passive strategy capable of reducing heat gain by combining external cladding with a ventilated air cavity. Despite the proven potential of these systems, the literature shows methodological fragmentation and limited evidence specifically focused on warm semi-arid regions. The main objective of this research is to perform a comparative thermal assessment of six ventilated facade configurations generated from the combination of three cladding materials (Dekton, porcelain ceramic, and fiber-cement cladding) and two cavity depths (6 cm and 10 cm). The goal is to identify the relative influence of material properties and cavity geometry under extreme climatic conditions and to establish preliminary design criteria applicable to architectural practice. The methodological approach integrates three components: (1) a selective review of the scientific literature to identify dominant parameters affecting ventilated facade performance; (2) the construction of an analytical matrix to systematize and prioritize these variables; and (3) a simplified thermal modeling procedure based on a one-dimensional series-resistance formulation applied to a southwest-oriented classroom of the Biotechnology Building at the Universidad Autónoma de Querétaro. Representative boundary conditions were adopted (Text = 40 °C, Tint = 26 °C) along with standard convection coefficients for external, internal, and cavity interfaces. Results show that the steady-state heat flux transmitted to the interior remains within a narrow range (≈ 8.06–8.23 W/m²), indicating that cavity ventilation exerts a more dominant effect than cladding conductivity under the adopted assumptions. These findings provide a quantitative foundation for early-stage design decisions in warm semi-arid climates and underline the relevance of cavity depth and insulation in optimizing passive cooling performance.