Thermal performance of a ventilated façade in a lightweight experimental prototype for a temperate-cold climate with high solar radiation

Abstract

This study analyzes the impact of incorporating a ventilated façade (VF) system on the thermal performance of a lightweight experimental prototype representative of envelopes used in low-cost constructions in the Metropolitan Area of Mendoza (temperate-cold climate with high solar radiation). Two full-scale prototypes were built: one retrofitted with a VF and another without intervention (control case). The VF consisted of a second skin made of light-colored fiber cement panels with open joints and a naturally ventilated air cavity. Indoor and envelope temperatures were monitored during summer and winter, with records taken every 15 minutes. In winter, the VF increased minimum indoor temperatures by 1.2 °C and reduced maximum temperatures by 3.2 °C, decreasing the daily thermal range by 4.4 °C. In summer, maximum indoor temperatures were reduced by 5.0 °C and the mean daily ΔT by 6.2 °C. Envelope measurements confirmed vertical thermal gradients consistent with the stack effect. The results validate the VF as a passive energy retrofit strategy to improve thermal comfort and reduce cooling and heating loads, with potential for implementation in low-cost, locally adapted construction solutions.