Nowadays, it’s essential to reduce our reliance on conventional air conditioning units and switch to desiccant-based dehumidifiers and air conditioners. This shift promotes sustainability, protects the environment from harmful gas emissions, and minimizes energy consumption. The current work centres on developing a polymer-based dynamic desiccant dehumidifier system. This involves studying the velocity ratios between the dehumidifier and regenerator air at various rotational speeds. Four sets of velocity ratios and four sets of rotational speeds are included in the matrix preparation. The results indicated that the system performed optimally with a velocity ratio range of 1.00 to 0.20, demonstrating improved temperature and humidity changes as well as dehumidification efficiency. In contrast, the highest velocity ratio range of 4.00 to 0.80 achieved the maximum rate of moisture removal, performance coefficient, and coefficient of mass transfer at an optimum rotational speed of 24.0 rpm. Beyond these ranges, performance declined significantly. This unit reached a maximum rate of moisture removal of 0.23 g/s, dehumidification efficiency of 83.7%, a coefficient of performance of 5.36, and a coefficient of mass transfer of 6.67 kg/m²-s. Highlights As the velocity ratio decreases, both efficiency & moisture removal rate increase. Dehumidification performance improves up to 24.0 rpm, and then it declines. COP values of 1.87, 3.25, 4.24, and 5.36 are achieved for VR of 1.00, 2.00, 3.00, and 4.00. Power consumption & pressure drop rise with the velocity ratio & wheel speed. Mass transfer coefficient of 6.67 kg/m²·s is obtained at 24.0 rpm & VR of 0.80.

Cooling and humidification are commonly used in air conditioning systems, particularly for cooling applications. Evaporative cooling utilizes packing materials that retain water particles on their surface, increasing interaction with the incoming fluid stream. At the same time, filtration efficiently removes impurities from the water. This paper focuses on a novel approach where a grey water is used for humidification process with filtration using a naturally avaliable packing. It involves in designing a combined humidification and filtration unit, where grey water is filtered through a multi-stage filter to improve water quality. The water is then uniformly distributed over packing, while air moves in a counterflow arrangement to produce cold, humidified air. Luffa packing is used in this study, and its performance is compared to standard Celdek 7090 packing. Experiments were conducted at varying Reynolds numbers with a fixed water flow rate. Results showed that Celdek packing exhibited slightly higher humidification performance than Luffa packing, with a deviation of less than 20%. The dual-stage unit achieved an efficiency of 71.11%, a Coefficient of Performance (COP) of 1.16, rate of evaporation of 0.39 g/s, & pressure drop of 63.33 Pa. And the water flow rate of 2 LPM yielded optimum humidification values. Grey water filtration was performed both with and without activated charcoal, demonstrating the unit's efficient filtration capabilities.

Present work focuses on sustainable energy-based technique for achieving the required thermal comfort inside a greenhouse unit. A region of definite volume is built, and the plants are placed inside it. Evaporative cooling setup consists of cooling pads, water spray unit and a blower are designed to regulate the ventilation inside the space. Experiments are conducted for a fixed peak time and changing the flow rate of air. Results indicated that the maximum temperature drop, and relative humidity drop values are observed to be 7.7°C and 22%. It is seen that optimum performance could be obtained for an airflow rate of 12 m/s and the corresponding Coefficient of Performance (COP), evaporation rate and cooling efficiency values are 2.4787, 0.1181 g/s and 60.05%, respectively.