Experimental study on the performance of various porous water-absorbing fiber materials for indoor humidification

To increase the relative humidity in heating rooms in winter, a new humidification method is proposed. The capillary water absorption performance of porous fiber materials is utilized to compose a bottom water-absorbing component, and the spray device of the traditional direct evaporative cooling system is eliminated, which can be used for miniaturized heating humidification devices. To compare the heating and humidification performance of various fiber materials, an experimental system was designed and constructed with fiber materials arranged in parallel as humidification components. The experimental materials include nonwoven fabric (Sample A), polyester fiber (Sample B) and fiber cotton (Sample C). The experimentally obtained temperature drop is lower than the conventional evaporative cooling system, and the relative humidity enhancement is between 6 % and 15 %. Sample B had a maximum temperature drop of 6.83 °C, a maximum relative humidity increment of 14.07 %, a maximum humidification capacity of 272.4 g/h, and a maximum humidification capacity per unit area of material of 972.86 g/(m²·h). The maximum humidification capacity of Sample B was 13.8 % higher than that of Sample A and 18.5 % higher than that of Sample C. The cooling energy density of the three samples was only within 330 J/m³ under all working conditions. Applying sample B to the fan coil unit increased the relative humidity by 33.8 % with only 0.3 °C temperature drop, providing humidification while heating the indoor air. This paper provides a theoretical basis for a fiber material humidification, which to some extent can meet the heating and humidification integration in winter.