Anyone know what those aluminum "fins" are called that you wrap around your boiler's flue pipe? The idea is that they increase the surface area of the flue pipe so it gives off more heat into the room through convection. Made of a long strip of light gage sheet metal bent back and forth then wrapped around the flue pipe. Can't find them anywhere, are they still made?

They might be made by some obscure company but I have not seen them for awhile. If they worked well they would be selling like hot cakes and would be advertised on TV late at night with the energy prices so expensive.

While it sounds like a good idea I do not believe they actually worked well. One word of caution. On a standard furnace the flue gas has to be maintained at a temperature that will not cause condensation. To much heat extraction from the flue pipe can cause major problems two of which are rust and corrosion.