## 3 Case Study  
### EAHX Location, Climate and Soil Temperature  
The studied EAHX (and the building it serves) is located in the Alentejo region, in Portugal, approximately 40 km east from the district capital, Beja, with climate variety Cas--Mediterranean climate with hot and dry summer [37].  
Figure 6 presents box and violin plots obtained from (instantaneous) outdoor air temperature and relative humidity data collected at the EAHX location between June and September.  
Figure 6 shows that mean monthly air temperatures exceed 20 \({}^{\circ}\)C, reaching 26 \({}^{\circ}\)C in July. Maximum temperatures exceeded 40 \({}^{\circ}\)C in June and were higher than 35 \({}^{\circ}\)C in July and August. The relative humidity interquartile range is defined (approximately) between 30 and 70%, and an increase in monthly mean relative humidity is observed from June to September.  
Regarding the soil, rhodo-chromic-Luvisols [38] are typical at the EAHX location. Figure 7 compares instantaneous soil temperature measurements at the EAHX site, at 10 cm depth, with analytic results [30]. A fair agreement between measured and analytical soil temperature at this depth is observed.  
Analytical results at 5.5 m are also represented in Figure 7. At this depth, a pronounced reduction in annual thermal amplitude is expected, with temperatures varying approximately 2 K around the average annual value of 18.5 \({}^{\circ}\)C. Moreover, a phase shift delaying the lowest soil temperature by approximately 4 months, from January to May, is observed.  
Figure 7 also depicts dew point temperatures derived from instantaneous outdoor air temperature and relative humidity measured at the EAHX site. The purpose of including this information is to show that for warm months, between June and September, the dew point seldom exceeded the undisturbed soil temperature, supporting the low probability of condensation in the EAHX and supporting the horizontal sensible cooling line depicted in Figure 2.  
Finally, Figure 7 presents upper free-floating setpoints (category I to III of an adaptive thermal comfort model) as defined in standard EN 15251:2007 [28].  
Free-floating setpoints were determined from outdoor air temperature running means derived, in turn, from instantaneous outdoor air temperature measurements at the EAHX  
Figure 6: Box and violin plots for air temperature (left side/axis) and relative humidity (right side/axis) measured at the EAHX site.  
Figure 7: Measured and analytical [30] soil temperatures at the EAHX site for different depths. Ribbon visible in the 5.5 m analytical curve delimits cases with soil diffusivities from 2 \(\times 10^{-7}\) to \(10^{-6}\) m\({}^{2}\)/s with the centerline obtained with \(\alpha_{s}=6\times 10^{-7}\) m\({}^{2}\)/s. Instantaneous dew points and daily upper free-floating setpoints [28] (categories I to III) obtained from outdoor air measurements at the EAHX site are also presented (June to September only).  
site. From June to September, upper free-floating setpoints lay above 28 \({}^{\circ}\)C (category I upper limit), reaching 32 \({}^{\circ}\)C (category III upper limit) for most of July and August. This information is relevant for the definition of the office room design air temperature setpoint used in the next section.