One of the most common questions we get, since you do have to refill our products every few weeks, is where the water goes.

While our systems are indeed closed, they are not sealed.  This means that the water won't splash out - but water vapor can still permeate in microscopic amounts through any of the tubing in the pad or unit.

The science basically boils down to the fact that water molecules are constantly in motion - and when excited via heat and movement, are able to penetrate into the tiny spaces between the tubing molecules via a process called diffusion.  Then, once inside the tubing, the water molecules exert a vapor pressure that - if exceeding the partial pressure of the water vapor in the air - allows these molecules to escape into the air.

This process is influenced by the temperature of the water in the system, and the temperature and humidity in the surrounding environment.  In short, the higher the temperature you operate your system at, the more often you'll need to refill it.