A system for quantifying the cooling effectiveness of bicycle helmets

This article describes the design and development of a system that is capab le of quantifying the thermal comfort of bicycle helmets. The motivation fo r the development of the system stems from the desire both to increase helm et use and to provide the designer with a quantitative method of evaluating the thermal comfort of a helmet. The system consists of a heated mannequin head form, a heated reference sphere, a small wind tunnel, and a data acqu isition system. Both the head form and the reference sphere were instrument ed with thermocouples. The system is capable of simulating riding speeds ra nging from 4.5-15.5 m/s. A cooling effectiveness, CI, that is independent o f both ambient conditions and wind velocity is defined as a measure of how well the helmet ventilates as compared to the reference sphere. The system was validated by testing six commercially available bicycle helmets manufac tured between approximately 1992 and 1998. [S0148-0731(00)02304-9].