Vamsi Kondapalli (PI), Kyle Brittingham, Vesselin Shanov

University of Cincinnati, Mechanical and Materials Engineering

Firefighters while wearing personal protective equipment (PPE) are often exposed to high temperature and physical strain during training and real scenario duty. Hyperthermia is a medical condition due to an abnormal rise in body temperatures above 40oC and can lead to heatstroke thus becoming fatal. Cooling products, like cold packs, are commercially available, however, they only cool the user for several minutes and are made for one-time use. This project focuses on making a prototype helmet with highly efficient thermoelectric (TE) cooling to reduce the head`s temperature of individuals such as construction workers, firefighters, miners, etc. The cool helmet employs a heat spreader for transporting the metabolic and external heat to the TE cooler. A wide variety of heat spreaders like copper foil, commercial carbon veil (CV), CV-cloth composites and graphene composites with 3.5 times the thermal conductivity of copper have been tested taking their cost, mechanical stability, availability, weight, and environmental impact into consideration. The cool helmet was evaluated by heating from the top and the bottom using an incandescent bulb. The temperature was measured and mapped within the 3D space of the helmet by multiple thermocouples and an infrared camera FLIR T1010. The heating and cooling temperature data revealed that the addition of CV and copper foil greatly enhanced the cooling rate compared to the materials normally used in conventional helmets. Further, with the tested heat spreader and TE cooler turned on, the heating time to critical temperature of 40oC was increased by more than 3 times, which confirmed the functionality of the cooled helmet.