The system consists of three independent subsystems, which were built on the upper roof and the two sides of the conditioned house. Basically, during one 24 h cycle, each subsystem undergoes a regeneration process when it is exposed to sunlight and undergoes a dehumidification process when it is covered by shadow or in the dark at night. Each subsystem contains three solid desiccant beds and the upper one has an additional radiative cooling facility. The solid desiccant used in the system is silica gel, of which the particle size is (~8 mesh. By analysis of the experimental data, the upper subsystem has the best performance for both the dehumidification and regeneration processes, followed by the East subsystem; the West one is the worst. There are several characteristics of this system: firstly, it can continuously supply the conditioned space with processed (or dehumidified) air 24 hours a day ; secondly, it contains many functions which are suitable for public use like air conditioning, drying, dehydration and active cooling. Thirdly, since the only energy consumption of the system is from the ventilation fans plus the enormous free solar energy input to regenerate the system, its energy efficiency is incredibly high, and finally, a large potential for dehumidification in such a humid area as Taiwan is expected.