Air Cooled

Module from the Heat Exchanger Engineering Curriculum curriculum.

Module 5 - Air Cooled Heat Exchangers (API 661) · Learning Objectives · 1. Apply API 661 scope and design basis (induced vs forced draft) · 2. Size bundle per HPS/HPS method: Uair ~ 90-120 BTU/hr-ft2-F finned · 3. Compare forced draft vs induced draft (service, maintenance, efficiency) · 4. Select finned tubes: L-fin, G-fin, extruded, embedded by service T · 5. Design for fan sizing, noise, and failure mode (fan blade, bearing) · Finned Tube Types

Fin Type	Max T (F)	Cost	Corrosion	Notes	Typical
L-foot (wrap-on)	250	Low	Low protection	Al fin over CS or SS tube	Standard ambient
G-embedded (grooved)	650	Medium	Better adhesion	Wound Al groove	Process services
Extruded (bimetal)	550	Medium-High	Excellent	Al sleeve over CS	Sour service
Welded serrated	900+	Highest	Full	Steel-steel fins	High-T, fired service
Cold-wound (Klingon)	300	Medium	Good	Al fin	Common commercial

Source: Heat_Exchanger_Engineering_Curriculum_v1.xlsx · Sheet: Air Cooled

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