Suitability of natural composite desiccant assisted evaporative cooling for sustainable net zero energy green building

• Preparing organic cow dung composite desiccant. • Coating cow dung composite desiccant on wood pulp fiber paper matrix. • Evaluating DCOP, DC, and MRE of different cow dung Composite desiccant beds. • Cow dung composite desiccant performed better with 0.643 g/g of moisture uptake. • Maximum DCOP of CDC-WPFP desiccant bed is 2.52 at 50 °C regeneration temperature. This paper investigates the adsorption capacity of the organic cow dung desiccant and its composites for application as a desiccant for desiccant dehumidification systems. The composite desiccants of cow dung with calcium chloride (CDC) and with silica gel (CDS) were prepared as a solution with Hydroxyethylcellulose and coated on a Wood Pulp Fiber Paper (WPFP) substrate and their adsorption ability was studied for different temperatures (25, 35 and 45 °C) and RH (75, 85 and 95 %). The desiccant bed of size 30 × 30 cm with desiccant CD, CDS, and CDC coated on the Wood Pulp fiber paper was prepared and subjected to dehumidification and regeneration. The dehumidification capacity (DC) and dehumidification coefficient of performance (DCOP) of the CD, CDC, and CDS composite desiccant beds were analyzed. The composite CDC performed better than others with a moisture uptake capacity of 0.643 g/g by reaching saturation in 80 min. CD, CDC, and CDS desiccants show faster regeneration within 30 min at the regeneration temperature of 80 °C. The CDC-coated Wood Pulp Fiber Paper performed better and the DCOP was maximum with a value of 2.52 at 50 °C regeneration temperature considering 50, 60, 70, and 80 °C.