Energy-efficient low-temperature activated desiccant wheels with nano-desiccant-coated fiber matrix

Air-conditioning system applies dehumidification by condensation technique, where the cooling coil handles both latent and sensible load. Energy consumption by the system increases by handling both loads. In order to reduce operating energy and load on cooling coil, latent load needs to be reduced or eliminated. Latent load can be handled separately using desiccant-type dehumidifiers irrespective of cooling coil temperature. This paper investigates the dehumidification performance of a desiccant wheels (DWs) made of fiber paper substrates such as Ceramic Fiber, Glass Fiber, Wood Pulp Fiber, Nomex Fiber, and Brown Wood Pulp Paper (BWPP) coated with synthesized mesoporous nano-titania desiccant for energy-efficient air-conditioning. Moisture adsorption ability test was conducted for different fiber papers at 30 °C and 75% RH, where BWPP has maximum moisture adsorption of 38 g m −2 and 0.42 g g −1 due to its hydrophilic nature, with the highest coating ratio of 3.5 g cm −3 . The thermal conductivity, nitrogen adsorption/desorption isotherm, pore structure, and thermal stability of the fiber substrates were also analyzed before and after coating. The thermal conductivity of the fiber papers coated with nano-titania desiccant has enhanced compared to the raw fiber papers, and it reaches 0.116 W m −1 K −1 for BWPP. The dehumidification coefficient of performance of BWPP–DW at a 1:1 airflow area ratio, 60 °C regeneration temperature, and 10 rph is 0.82. The BWPP matrix DWs can be reactivated by low-grade energy sources with 0.82 kg kW −1 h −1 and saves energy up to 2.39 times.