I'm in a technical highschool learning plumbing and heating. Missed a day of school and he gave me a project on the title above. Problem is he never taught me anything about a hot air system so I'm clueless on how it works and what have you. Hot water makes perfect sense. Tried googling but it sounds super inconclusive and sounds like someone just made it all up in about 10 seconds. I have to compare and contrast the difference between the two assuming all things are constants (size of house, type of fuel, etc etc) with the only difference being the heating system. Could someone please fill me in and educate me on the pros and cons of a hot air system? Thanks a million!