I had never heard the word “desiccant” before, let alone how to cool something using it. I was watching a show on Planet Green called Solar Showdown which, if you haven’t seen it, is about a contest sponsored by the Department of Energy looking for the most efficient solar powered home. One of the homes was using desiccant cooling, which they claimed was new and hadn’t been done before in a residential application, and that it was a very low energy and efficient way to cool a home. How their process worked was they used a waterfall with a desiccant additive. The extra “humidity” is then carried, somehow, through the waterfall to the outside and is then released through a series of vertical tubes. They didn’t give any in-depth details of the process, unfortunately.
So what the heck is it? According to Merriam-Webster, desiccant means “a drying agent (as calcium chloride)” – like those little packets you find in new shoes. A desiccant cooler works on the premise that if the humidity is removed from the air inside the house then not only does it feel more comfortable, but the air is easier to cool by AC. Here is a better explanation of the practice in general.