Personalized Evaporative Cooler to Reduce Energy Consumption and Improve Thermal Comfort in Free-Running Spaces

Abstract

The need to reduce energy consumption in buildings is imperative, but we must maintain individual thermal comfort of the occupants to ensure their well-being and productivity. Personal conditioning systems (PCS) have been suggested as a strategy to achieve both energy efficiency and thermal comfort, as they are considered to be low-energy consumers, allow increasing set-point temperatures, and give occupants the chance to control their own personal environment. While most warm-environment PCS are based on air-movement devices, the potential of using desk direct evaporative coolers (dDEC) has been scarcely explored. This work presents the results of the characterization of a dDEC and its potential for improving the indoor temperature and thermal comfort in a free-running office space. The study proposes adapted corrective power (CPa) and cooling fan efficiency for evaporative systems (CFEe) indexes. Results show that the dDEC achieves thermal comfort with a local effect, and it is recommended to be positioned directly on the desk surface, orientated to the occupant, and at a certain distance. Under these conditions, the CPa reaches −2.8 °C, involving better CFEe than the desk fans studied in the literature. Speed has little effect on the local air conditions, though it does improve the perception of thermal comfort. The relative humidity of the air does not exceed the recommendable limits, but renovation of the indoor air enables better conditions.

User Thermal Comfort in Historic Buildings: Evaluation of the Potential of Thermal Mass, Orientation, Evaporative Cooling and Ventilation

“…There are several some other methods for evaporative cooling such as spray passive Downdraft evaporative cooling (PDEC) which has been intensively investigated such as the work of Kang [46]. In a study conducted by Ana [47] highlighted that use of evaporative cooling systems can achieve thermal comfort level with a free running operation system in the climate of Spain. This study used wide range of tools to conduct the study, Table 2 indicates equipment used.…”

Thermal Comfort Chamber Study of Nordic Elderly People with Local Cooling Devices in Warm Conditions

“…In addition to a variety of fans that enhance airflow, numerous new devices for lowering the supply air temperature, such as evaporative cooling devices, have been introduced [52]. Tejero-González et al [53] demonstrated that evaporative cooling devices can substantially improve thermal comfort in open office spaces. These devices are low-power, easy-to-use, and efficiently ensure human thermal comfort under certain conditions.…”

Increase of energy efficiency ratio of a direct evaporative cooler by dynamic behavior with energy and exergy analysis

“…7–17 Some researchers have recently conducted theoretical and experimental studies on these new hybrid DEC and IDEC applications. 18–28…”

“…[7][8][9][10][11][12][13][14][15][16][17] Some researchers have recently conducted theoretical and experimental studies on these new hybrid DEC and IDEC applications. [18][19][20][21][22][23][24][25][26][27][28] Rong et al 29 have experimentally investigated the dynamic behavior of cellulose pads, including cooling efficiency and dry-bulb air temperature drop, water consumption under the influence of parameters such as different air velocities, different dynamic circulation rates (due to the varying lengths of on and off operation periods of the pump). They used 21 different time patterns for the periodic operation of the pump at different air velocities.…”