This paper describes the application of particle image velocimetry (PIV) to the large-scale flow fields in the vicinity of a person in a room. Due to the large imaging areas required for such measurements (over two meters in each dimension) and the low air velocities (0.05 m/s), the PIV technique for this application encounters unique challenges. Such challenges include uneven illumination, large relative velocity errors, and large out-of-plane displacements within the thick light sheet. A fully integrated PIV system with two-dimensional data processing software was implemented specifically to meet these challenges. Cross-correlation was employed for PIV velocity extraction, and a simple but effective subpixel calculation scheme was devised to improve the accuracy of the correlation peak location. Also, a technique for correction of in-plane velocity errors due to the out-of-plane velocity component was developed. This PIV technique was applied to the measurements of the large-scale air motion around a thermal manikin in a well-controlled environmental chamber. The experimental air velocity data describing the interaction between the human body and the room airflow generated in this study are intended to be used for validation of CFD models for room airflow predictions.

Units: Dual