That's a Tesla coil. Toroid is made from dryer vent. It has nothing to do with venting heat, it was just a convienient material to use. It's a lightning generator. Its meant to be run either outside or in a big open space like a garage. It's portable, that's just where I keep it when I'm not working on it.
Heres one (not mine) in operation. They're really neat.
Looks like a fire in the ceiling will be starting soon....do you know that long-term exposure to low warm temps reduces the flash point of most materials? Including any beams above the drywall