A model for condensate retention on plain-fin heat exchangers

A. I. ElSherbini, A. M. Jacobi

Research output: Contribution to journalArticlepeer-review


A model has been developed for predicting the amount of condensate retained as drops on the air-side of heat exchangers operating under dehumidifying conditions. For a coil with a given surface wettability, characterized by the advancing contact angle, the maximum diameter for a retained drop is obtained from a balance between gravitational and surface tension forces. A logarithmic function is used to describe the size-distribution of drops on fins, based on the fraction of fin-area covered by liquid. The volumes of individual drops are calculated by a geometric method for approximating the three-dimensional shapes of drops on vertical and inclined surfaces. The total volume of condensate accumulated on a coil is then found by multiplying the size-distribution and volume functions and integrating over all drop diameters. The model is successful in predicting measurements by other researchers of the mass of condensate retained on plain-fin heat exchangers. The critical fin spacing to avoid the formation of condensate bridges is also predicted.

Original languageEnglish (US)
Pages (from-to)427-433
Number of pages7
JournalJournal of Heat Transfer
Issue number5
StatePublished - May 2006


  • Condensation
  • Heat exchangers
  • Retention

ASJC Scopus subject areas

  • General Materials Science
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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