The Complete Handbook of Moisture Absorbers

Chapter 1: Understanding Moisture Absorbers

Walk into any hardware store and you will see a wall of products designed to fight moisture problems: small plastic tubs of white pellets, hanging bags, boxes of chemical powder, and more expensive electric units. On the surface, these are all just different ways of doing the same thing. But the moment you step beyond your own damp basement or musty RV and start dealing with the precise needs of a warehouse, a museum storage room, or a boat, the difference between getting the job done right and just doing something becomes a matter of real costs and potential damage. A moisture absorber is not a magic product that sucks water from the air. Every one of them is an engineered system that exploits a fundamental physical law to move water vapor from the air into a material or surface you can dispose of or drain away.

To understand how they work, you first need to understand what is actually in the air. The air around you is a mixture of gases and water vapor. The amount of water vapor it holds is not a fixed number but a maximum that depends on temperature. Warmer air can hold more water vapor than cooler air. This is why a cold glass of water on a hot day develops beads of sweat on the outside. The air near the glass is cooled below the point at which it can hold its moisture, so the excess condenses into