Experimental studies on the air-side heat transfer and pressure drop characteristics for 16 types offset strip fin heat exchanger and flat tube heat exchangers were performed with such parameters as fin space s

fin height h

fin thickness t

fin length l and flow length d.A series of tests were conducted at air side Reynolds number of 500—7500

and constant tube-side water flow rate of 2.5 m3·h-1.The air side thermal performance data were analyzed by using the effectiveness-NTU method.The heat transfer coefficients and pressure drop data for different fin space s and fin length l were reported in terms of frontal air velocity.The general correlations for j and f factors were derived by regression analysis and F significance test

and the correlations had a RMS error of ±10%.The absolute mean deviations for the j and f factor correlations were 4.2% and 5.3% respectively.