## 3 Results and Discussion
### EAHX Room Load Removal: Assessing Standardone EAHX Cooling and EAHX Design
Still, Figure 10 shows that the built EAHX delivers room cooling capacities of 10 W/m\({}^{2}\) with approximately 100% probability, and delivers room cooling capacities of 15 W/m\({}^{2}\) with 32% to \(\sim\)100% probabilities (from 0.4% to 2% design dry-bulb outdoor air temperatures). This means that despite being insufficient, a significant part  
Figure 9: Hourly violin- and box-plots for specific (and absolute) EAHX room load removal—\(q_{\rm rfill}^{\rm EAHX}\) (\(Q_{\rm rfill}^{\rm EAHX}\))—and for specific (and absolute) EAHX outdoor air load removal—\(q_{\rm oa}^{\rm EAHX}\) (\(Q_{\rm oa}^{\rm EAHX}\)). Obtained from monitored data (between 1 June and 30 September; cooling mode only, \(T_{\rm aL}<T_{\rm a0}\); 8000 m\({}^{3}\)/h nominal airflow rate; 450 m\({}^{2}\) of cooled floor area) considering Category III comfort expectation level. Grey shading highlights room occupied period. Left and right axis depict specific and absolute load removal, respectively. of the room design cooling demand (at least more than 50%) is already provided by the built EAHX. As regards the built EAHX standalone use, these results lead to the following conclusions:  
1. The built EAHX operates in standalone mode, delivering the required room _design_ (or peak) cooling demand and providing acceptable comfort in the cooled rooms (Category III [29]), if outdoor air temperature does not exceed 33 \({}^{\circ}\)C (2% annual cooling design dry-bulb outdoor temperature [38]). 2. For outdoor air temperatures exceeding 33 \({}^{\circ}\)C, the built EAHX allows for room cooling during the whole summer; however, room load removal is insufficient to meet the room _design_ cooling demand. If room comfort Category III is judged to be appropriate, the built EAHX provides, on its own, more than 50% of the room _design_ cooling demand. 3. If high room comfort is expected (Category I [29]), the built EAHX ceases room cooling for outdoor temperatures exceeding 37 \({}^{\circ}\)C (the 0.4% annual cooling design dry-bulb outdoor temperature [38]). To meet/deliver the additional room cooling demand necessary for cases (ii) and (iii) above, the following strategies could be implemented:  
1. Alter the EAHX design; for example, increase pipe length, change pipe layout. 2. Complement EAHX room load removal with passive cooling techniques, e.g., forced nighttime ventilation and appropriate use of building thermal mass. The first of the above strategies is useful for future EAHX design, not for the built one. The second strategy is described in [PERSON] et al. [16] and several other authors [10,18], and is available with the researched cooling and ventilation system, as already mentioned in Table 2, item (n). The analysis of the performance of the hybrid EAHX-TM cooling and ventilation system (as classified by [PERSON] et al. [39], with TM standing for building thermal mass), requiring the joint research of the built EAHX and the existing building/distribution piping, falls out of the scope of this paper. However, considering experimental results found in studies dealing with building nighttime ventilation [18,40,41], with significant (\(\sim\)2 K) room peak temperature reductions and the significant decrease in refrigeration machine cooling need (up to 50% reduction [42]), the built hybrid EAHX-TM system should extend the range of outdoor air temperatures for which the room _design_ cooling demand is met. Figure 10: Probability that the EAHX specific (room) cooling capacity is greater or equal to a specific room cooling demand, \(\vartheta_{\text{r}}^{\text{BLDG}}\); conditional to outdoor air temperature being equal to \(T\). Obtained from monitored data (between 1 June and 30 September; cooling mode only, \(T_{\text{aL}}<T_{\text{a0}}\); 8000 m\({}^{3}\)/h nominal airflow rate; 450 m\({}^{2}\) of cooled floor area) considering Category III comfort expectation level.