tubular heating element / finned

In applications where tubular heaters are exposed to forced convection, placing fins around tubular heaters increases their surface area and thus improves their heat transferring capacity. Finned tubular heaters, compared to regular tubular heaters, run at lower surface temperatures for the same watt densities when placed in identical air streams. Despite their advantages, finned tubular heaters are not recommended for applications where outlet air temperatures exceed 600?F.
the physical characteristics of a finned tubular heater play a major role in the effectiveness of its heat transfer.

Some applications require stainless steel materials for corrosion resistance. The most efficient finned heaters are made with steel sheath and steel fins. Steel is normally used for air heating, stainless steel for atmospheres which are humid or corrosive and monel for salt-laden humid atmospheres. Keep in mind that stainless heaters with stainless fins are very inefficient since the heat transfer rate of stainless is less than one quarter that for steel.