Running a phase change system for 24/7 is not a really good idea. Like Nubius said, it's for suicide shots. Check out some extreme forums.
Has a really great forum, dedicated totally to the art of phase change. There is alot to learn on phase change, as I have been doing almost nonstop research for the last few weeks on it. Go to sites like http://www.howstuffworks.com
and read up on how refrigerators work. Learning how any type of cooling system works would be of gret knowledge to you. Learn how a refrigerator works, an air conditioner, things like that, and they will all help you more easily understand a phase change. When you first start learning, it is extremely overwhelming, but stick it out. There are things that once you find them out (very very small things) it makes all the bigger, more confusing things fall into place.