Enhancing the dehumidification efficiency of solar-assisted liquid desiccant air dehumidifiers using nanoscale TiO 2 super-hydrophilic coating

Abstract

Humidity control of indoor air is very important to both indoor occupants and indoor building materials. The liquid desiccant air dehumidifier is attracting much attention due to its lower energy consumption. However, the incomplete wetting conditions present negative effect on the development of liquid desiccant air dehumidifiers. Therefore, this paper aims to develop a novel nanoscale TiO2 super-hydrophilic coating to increase the surface wettability and improve the dehumidification performance as well. XRD test and FESEM test are conducted to investigate the characteristics of the TiO2 super-hydrophilic coating. The dehumidification performance is significantly improved by the coating. The absolute humidity change increases from 3.2 g/kg to 4.9 g/kg and the mass transfer coefficient from 70.05 g/(m 2 s) to 90.05 g/(m 2 s) . The performance enhancement is attributed to the increase of wetting area and the decrease of falling film thickness. This research provides an effective approach to improve the dehumidification performance and to reduce the building energy consumption.