In this paper, a test rig was constructed to measure the sensibility and enthalpy effectiveness of a plate-fin total heat exchanger (PFFHE). Combined with finite element method, the influence of airflow distribution was analyzed, and an improved PFTHE was subsequently introduced. Utilizing the test rig, the study measured the sensibility and enthalpy effectiveness of the improved PFTHEs with air deflectors and different air spreader plates. Results show that the sensibility and enthalpy effectiveness of the PFTHE are optimized at 17.4% and 7.8% airflow rates, respectively. (C) 2014 Elsevier B.V. All rights reserved.