Anhydrous CaCl2 is very hygroscopic and tends to absorb two water molecules per molecule of salt.
Compared to conventional silica drying agents CaCl2 shows an up to
six times higher humidity absorption rate.
Dr. Daichi Nasu
Experience shows that silica gel is not a very reliable solution to control the air humidity. We can provide you with a very effective drying agent with a water absorbency of almost 280% at 25°C:
COMPOSITION – THE DRYING AGENT FOR HIGHEST DEMANDS