Dido, nay on the tube.
You really can't beat the heatercore, no matter how you look at it, unless you're an aircraft mechanic...
The results should be interesting though. If the inner tube was finned, and the whole assembly was a lot longer, like 3 to 5 times, I'd say "use it", but by then, you'd have the same flow restriction as a core, and you'd have a massively large contraption. Unless you've got a large cold basement...
|