Here are the three main types:
Water Absorbers – Usually composed of porous bags or tubes of crushed corncobs, these products can hold up to 1000 times their weight in water, and are used for collecting water after flooding, leaks, or other water damage.
Electric Dehumidifiers –These appliances reduce moisture in the air by drawing warm, humid air into a cold chamber and then collecting the moisture that condenses.
Moisture Absorbers – Non-electric dehumidifiers consisting of chemical or natural compounds that naturally absorb excess humidity from the air.
When comparing electric versus non electric versions, most people find that the non electric version has some distinct advantages, including being simple to use, inexpensive, requiring no maintenance and being very effective.
Non-electric moisture absorbers usually use one of three main types of absorbent materials: Silica compounds, clay absorbers, and calcium chloride. Silica compounds are toxic. Clay is the least effective at absorbing excess moisture. Calcium chloride is the superior choice. This compound is a mixture of chlorine and calcium (salt). It has strong moisture absorbing properties and works great for basements, kitchens, cabinets, closets, crawl spaces and other damp indoor spaces.
DampRid is the original non-electric dehumidifier, using white, calcium chloride crystals to bring humidity to an ideal and safer level of below 50% to help prevent musty odors. Best of all, once the optimal moisture level is reached, DampRid Moisture Absorber automatically slows down the absorption process and then restarts as necessary.