Relative humidity control and reduction in power consumption via desiccant dehumidification

Abstract

Variation in relative humidity has caused many environmental and health problems. Therefore, controlling of the relative humidity is necessary to improve indoor air quality. Solid desiccant dehumidifiers play a significant role in this direction through using rotating desiccant wheel made of silica gel. The current study investigates new approach by conducting experimental test on desiccant dehumidification to determine the performance of the desiccant wheel. Experiments were carried out by making the desiccant wheel active by supplying different amount of heat and varying incoming air flow rates, while the speed of the rotating desiccant remained constant. The results show that the desiccant wheel is able to reduce relative humidity to 40% at dry bulb temperature of 55 °C in a period of time without supplying heat energy in 10 minutes. When the desiccant was activated with a temperature of 170 °C and air flow rate of 243 kg/h the electrical heater was switched on for 15 minutes resulting in energy saving of about 75% compared with the energy consumption when the heater runs continuously. Thermal power input of 7 kW was determined to design an alternative heat energy source to reactivate desiccant wheel.