## 2 Case Study  
The experimental study was carried out in a winery built in O Savinao (42\({}^{\circ}\)33\({}^{\prime}\) N, 7\({}^{\circ}\)40\({}^{\prime}\) W, altitude 399 m above Mean Seal Level (MAMSL) in the province of Lugo, Spain. The construction of the building dates back to 1920, when it was inaugurated for the production of local wines on a small scale. Since then, the building has undergone structural modifications and extensions, some of which were not documented. The results of these changes make its study of great interest, as it presents some singular structures and an important diversity of construction materials; the south facade is semi-buried to keep the AAT constant inside during all seasons of the year.  
The exterior walls are mainly made of granite, and the doors, windows, and the structure supporting the roof are made of wood. Ceramic tiles were used for the wall cladding and the pillars and floor are built with bricks. Figure 1 shows the location of the winery and the exterior appearance of the building. Figure 2 shows a closer photograph of the exterior walls of the building and the interior.  
Temperature influences almost every step of wine production from the growing of the grape [26]. The process of wine maturation, which is particularly important, can be accelerated by high temperatures [27; 28]. To prevent loss of quality, the wine should be stored at a cool cellar temperature [29; 30]. The final wine quality can be controlled by monitoring the ambient air temperature inside the aging rooms [31], or even by means of sensors embedded inside wine barrels [32].  
The introduction of modern cooling systems into the wine industry has allowed for the production of excellent wines almost anywhere in the world, regardless of the surrounding climate. However, energy use during wine production still represents a high percentage of the total electricity used by the winery [33]. Traditional cellars are more energy efficient than modern construction practices [34; 35]. These traditional buildings incorporate bioclimatic strategies, such as the use of buried or semi-buried structures, adequate orientation, and natural ventilation [36; 37].  
Infrared thermography (IRT) techniques have been increasingly used in recent years due to their fast and reliable results in envelope inspection and their non-invasive nature [18]. This technology is adequate for evaluating thermal bridges, which are essential in energy audit procedures. Materials may not perform as expected, which is why mismatches between predicted and actual performance in buildings [38; 39; 40; 41; 42; 43] are common.  
Regarding the cellar where the study was carried out, it is important to point out that according to the Spanish Building Code CT-DB-HE [44], there are different climatic zones in the different regions of the country. This fact defines several wine production zones to which the so-called Denomination of Origin (DO) is assigned.  
The winery studied corresponds to the Ribeira Sacra appellation. In this area of Spain, the AAT is 14 \({}^{\circ}\)C, and the average annual rainfall is 900 mm. This region has a microclimate  
Figure 1: On the left, geographic location of the winery; on the right, general view of the building.  
Figure 2: On the left, the outer walls; on the right, the wine-ageing room (ground floor).  
with Mediterranean and continental influences due to its orography of steep slopes on the banks of the Mino and Sil rivers [45; 46].