Slit Fins: A Double-Edged Blade in Dirty Air
Slit and louvered fins are designed for one specific purpose: to break the air boundary layer, create controlled turbulence, and increase the heat-transfer coefficient. Under clean laboratory conditions, this geometry can raise the capacity of a fin-and-tube coil by 10 to 25% compared with a plain flat fin, which is why it looks so attractive in catalogs. But in units exposed to contaminated air, that same advantage turns into a weakness. The problem begins when the slits become particle traps. Industrial...
