The use of air conditioning technology is accompanied by an increase in electricity consumption, which is linked to an intensification of fossil fuel extraction. This in turn calls for developing cooling solutions of higher energy efficiency. The aim of this study is to examine energy consumption reduction of direct evaporative cooling technology for generating cool air in hot-dry climate regions. At the initial stage, already-installed air cooling equipment with a direct evaporative cooling system was studied for the creation of two regression models of electricity consumption representing the “on” and “off” sequences. Water consumption for system operation was taken into consideration. In the following stage, inlet water temperature dependence for pre-cooling purposes for the direct evaporative cooling system was studied. A mathematical model was developed and the subsequent calculations suggested that there is no need to pre-cool water before it enters the system and therefore consume additional energy. Practical application of this study is evaluated based on the case study in Dubai. The results of this study present significant energy saving potential for system operations of the direct evaporative cooling system of approximately 122 MWh per year. The return on investment for the equipment with direct evaporative cooling in case of an office building in Dubai featuring a hot desert climate is around 4.2 years. The purpose of this study is to examine the potential advantage of air cooling equipment with direct evaporative cooling technology compared to cooling equipment without this technology. The results provide the expediency of conducting further research in this area, in particular with regards to analyzing various materials for the adiabatic precooling pads, as well as the possibility of using a newly developed metal precooling pad.

As the cooling requirement and the energy prices are increasing rapidly across the world, the need to develop highly efficient cooling equipment is rising as well. Adiabatic cooling employs evaporation to pre-cool the air flowing through a closed-loop coil. This study examines various adiabatic evaporative cooling pads in terms of their pre-cooling potential and advantages over currently available technological solutions through isolating three cross-sectional metal cooling pad shapes (W, Z and Z1). The results of the study suggest that the correlation between Δt↓ and RH↑ is somewhat close in all three cases; however, a slightly higher temperature drop is observed when using a W-shaped metal sheet. Pressure drop variability was negligible under current cooling pad configurations and experimental boundary conditions. Further studies focusing on measurement continuity, longevity and boundary conditions’ variability are recommended.

This paper investigates summertime indoor overheating in naturally ventilated public buildings located in a cool temperate Baltic climate, where buildings are traditionally designed for heating-dominated conditions. The study is based on long-term field measurements conducted in two naturally ventilated rooms (a school classroom and a physician’s consultation office) and aims to quantify indoor overheating and examine indoor–outdoor thermal relationships. Indoor air temperature was continuously monitored and analysed together with concurrent outdoor air temperature and global solar radiation data. Overheating was assessed using fixed temperature thresholds (26 °C and 28 °C), exceedance hours, degree-hours, diurnal distributions, and indoor–outdoor temperature correlations; adaptive comfort criteria were not applied. The results reveal a pronounced contrast between the two spaces. The classroom experienced frequent and severe overheating and strong coupling to outdoor air temperature (R² = 0.60), whereas the physician’s office exhibited limited exceedance and a more buffered thermal response, with weaker indoor–outdoor coupling (R² = 0.32). These findings indicate substantial room-to-room variability in overheating behaviour, even under the same climatic conditions. While derived from a limited two-room case study, the results suggest that room-level assessment may be valuable for identifying overheating risks in naturally ventilated public buildings in cool-climate regions.