Chillwell A/C units. Do they work or is it a scam?

That looks like a more finished version of the “fan and a bucket of melting ice”, which actually does sort of work as an air conditioner because you can use the transition of ice to water to cool a room. It takes a good bit of ice though, a manageable amount if you have access to one of those big commercial ice machines, a bit harder if you’re just using a home freezer to make your own. This was discussed in another recent thread:

How should I cool my detached home office? - In My Humble Opinion (IMHO) - Straight Dope Message Board