The author of that answer was confused by a poorly written NASA PR document.
The majority of the humidity control on the US part of the ISS is not done using silica gel. It is done using condensing heat exchangers called Common Cabin Air Assemblies.
The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin air is controlled by the Common Cabin Air Assembly (CCAA). The CCAA consists of a fan, a condensing heat exchanger (CHX), an air/water separator, temperature and liquid sensors, and electrical controlling hardware and software.
The silica gel referred to in the other answer is a component of the CO2 removal apparatus (CDRA). It serves only to dry the air stream going through that apparatus.
This image shows where the silica gel is located in the CDRA (labeled SG).
The CDRA operates in a cyclic manner so that its various absorbing beds can first collect, and then later give up, CO2 and water. Each "half cycle" of the CDRA takes 144 minutes. During each "half cycle" one of the silica gel beds is collecting water and the other one is drying out, as explained in more detail in the rest of this answer.
The half of the CDRA that is absorbing passes air from the cabin through one of the desiccant beds (including silica gel), the fan, the heat exchanger, a CO2 removing sorbent bed, and then through the other desiccant bed and back into the cabin. On the diagram this is the red / dashed green / dashed red / blue line.
When the air stream passes through the first desiccant bed, it is dehumidified so that the CO2 removing bed will work properly (silica gel is gaining water). When it passes through the second desiccant bed, it dries out the bed (silica gel is losing water).
Meanwhile, the other CO2 removal bed is connected to vacuum (orange line) to get rid of the CO2 it has absorbed.
After 144 minutes, the valves reconfigure and send the air stream to the other CO2 removal bed, the first CO2 removal bed is connected to vacuum, and the desiccant beds reverse their roles.