[krazy]

That's most likely the meat of a baseboard-style heater (the radiator type, not the electric variety). I have a pair of them that are about six feet long in my basement plumbed into a boiler/heat exchanger project.

I don't know where to go about getting them as the two I have were in my uncle's garage and acquired for free.

I would definitely mount the unit so that air can rise convectively through the fins. Mounting it with the pipe running vertically would be counterproductive.

How far is it from the area you want to mount this thing to the level of the top of your computer? If it's going to work very well, it should be within a few feet ideally.