Calcium chloride is not the only substance that can be used to eliminate unwanted moisture. Another material frequently used for this purpose is silica gel, which is used to fill those little packets you may find hidden inside your new clothes, handbags, or shoes. But when it comes to reducing humidity in the air, which product is more effective? Which one absorbs more moisture? Let’s start with a bit of theory.
Silica gel is made from sodium silicate. It is granular in form and highly porous. This compound is not only able to absorb and retain moisture, it will also release that moisture when heated to temperatures of about 120 °C, which allows it to be used again. In about five hours, silica gel can absorb moisture equivalent to 30% of its own weight. However, after that length of time its ability to absorb moisture drops dramatically.
Calcium chloride is a type of mineral, an inorganic chemical compound that is used in the pharmaceutical and food industries, as well as many others. It is referred to as a hygroscopic material because it absorbs water vapor from the air, and it is also known as a deliquescent, because it transforms that water vapor into a liquid, in the form of an unsaturated solution.
So what can we learn from this theory? Which product is actually better for removing excessive moisture from the air? Let’s consider some facts:
– Silica gel absorbs and retains moisture, while calcium chloride is a deliquescent that attracts moisture and transforms it into a saline solution.
– Under conditions of 25 ºC and 70% relative humidity, calcium chloride absorbs 7 times more moisture than silica gel.
– Calcium chloride is able to absorb moisture even at low levels of relative humidity, although its capacity increases exponentially as humidity rises. In contrast, the ability of silica gel to absorb moisture remains about the same, even when the level of humidity in the air changes.
– Calcium chloride transforms the moisture it absorbs into a saline solution that can then be discarded. Silica gel retains the moisture inside of it, then releases it back into the air when heated to temperatures of around 120 ºC, so it can then be used again.
Clearly, when there is a need to solve problems caused by excessive moisture, calcium chloride is a much more effective material. Silica gel may be a good option for very small spaces, for short periods of time. However, calcium chloride is the best solution for eliminating excessive moisture in any type of space, not just because it is available in many forms and formats, but also because it is more effective and continues to work over longer periods of time.
Calcium chloride is the compound used in the wide range of moisture control products produced by HUMYDRY, which offer solutions for all the spaces in your home.
