This paper verifies the accuracy of a new transient test method for air-to-air energy wheels. To accomplish this, the transient characteristics of several energy wheels exposed to separate and independent step changes in humidity and temperature are measured. These characteristics are then used to predict the effectiveness of the wheels using the effectiveness model presented in Part I of this paper [O.O. Abe, C.J. Simonson, R.W. Besant and W. Shang, Effectiveness of energy wheels from transient measurements: Part I-Prediction of effectiveness and uncertainty, Int. J. Heat Mass Transfer, accepted for publication. [1]]. Comparison of the predicted latent and sensible effectiveness with experimental standard test data (steady state) show agreement within uncertainty bounds. Comparison with numerical simulations results also show agreement within the uncertainty bounds except for the special case of very low face velocity entering the energy wheels. (c) 2005 Elsevier Ltd. All rights reserved.