Add-on local sweating simulation system for a dry thermal manikin

This study develops an add-on local sweating simulation system to upgrade existing dry thermal manikins to local and sweating thermal manikins. The performance of this system was studied using a dry thermal manikin resembling a human lying on a bed with a ventilated mattress. The system comprises water-repellent porous hollow tubes to discharge water onto a diffusive fabric, as well as a motorized gear pump, DC power supply, relay module, microcomputer, and water container. Using the developed system, we maintained a cyclic steady-state for sweat generation; further, as simulated sweat, the tubes discharge distilled water over a wide area on the surface of a manikin segment covered with fabric. The local evaporative heat loss determined using the manikin roughly agreed with that calculated using the latent heat and water discharge rate, with a difference within 5 W/m². The humidity in the bed microenvironment was increased via the add-on sweat generation system and decreased via mattress ventilation. A dry thermal manikin with an add-on system is suitable for evaluating local cooling induced by sweating. The system has high repeatability (6% standard deviation); however, the accuracy of the water discharge rate (30%) needs improvement.