IoT sensor system for monitoring thermal inertia and climate efficiency in a residential house with double leaf opaque facade

A prototype residential house has been constructed in Southeast Spain, featuring an innovative double leaf opaque facade with a climate-controlled air chamber within the thermal envelope to ensure sustainable thermal comfort. Key innovations include the development of a new type of prefabricated concrete panel. This project primarily aims to demonstrate that air conditioning via air chambers in the thermal envelope is highly energy efficient and guarantees thermal comfort. As a secondary objective, to study and demonstrate the thermal behaviour and energy efficiency of the house over an extended period closed to a year, a scalable and low-cost IoT sensor system was designed with several data redundancy mechanisms to avoid data loss. The IoT system is built upon a wireless sensor network of 44 devices deployed in strategic points, using commercial off-the-shelf components. Each IoT device is battery-powered, employs a high-accuracy SHT31 temperature and relative humidity sensor, and uses a ESP32 module to send data periodically via Bluetooth Low Energy with optimized power consumption. The IoT devices provide reliable data every 5 min, with more than 90 % of them functioning properly throughout the long-term measurement campaign without battery replacement. The IoT system is complemented by an outdoor weather station. A multidisciplinary team, including experts in heat transfer analysis and energy efficiency, and IoT specialist engineers, collaborated to design and develop an affordable, high-quality data collection system. The overall IoT system and IT infrastructure are designed to be robust and simple, easing raw data gathering 24x7 for almost a year, thus facilitating data collection with minimal maintenance and workload.