Cool idea from kitchen to truck

Rice students’ cooling jacket for food truck workers gets a trial by fire 

If you can’t stand the heat and you can’t get out of the kitchen, what do you do?

If you work in a Houston food truck, you call upon Rice University engineering students to help you keep your cool.

The proprietor of the popular Pi Pizza Truck may be chillin’ this summer, courtesy of a team of Rice freshmen who pieced together a vest they expect will help him withstand Houston’s sultry summer nights.

Those nights are bad enough outside, as Houstonians know, but inside the truck where the pizza ovens keep the temperature upward of 110 degrees Fahrenheit, the conditions are much worse.

The team of mechanical engineering student George Zhu, bioengineering student Rahul Kothari, mechanical engineering and computer science student Christian Burkhartsmeyer and electrical and computer engineering student Andrew Graham created the vest that has internal pockets for cooling pads. They activate the commercial polyvinyl alcohol pads by dousing them in water – either hot or cold – and wringing them out. As the remaining water evaporates from pads placed near the skin, the steam or vapor carries body heat with it.

Testing with thermocouples at Rice’s Oshman Engineering Design Kitchen (OEDK) determined the packs cool the wearer for up to six hours, which matches Anthony Calleo’s 8 p.m.-2 a.m. business hours. (Although, they noted, the chef fires up his ovens two hours before opening.)

“He shouldn’t need to take the vest off,” Zhu said. “He should only have to recharge the pads once a day, but if he gets hot, he can keep spares in water and replace them.” Zhu said the 10 mesh pockets that contain the pads are held together with Velcro, making it quick and easy to replace them with fresh ones.

“I think we ended up with a functional design that keeps him reasonably cool,” said Burkhartsmeyer.

The team pointed out that, because of the ovens, air-conditioning the truck would be pointless. Graham noted the team visited Calleo’s truck last December and still had to take their jackets off while in the truck.

The team made a wise aesthetic decision when it went with basic black. “Intuition tells us that if we want to keep cool under the sun, we need to wear white,” Zhu said. But the truck opens at night, so the blazing sun is not a factor. Then there’s the pizza sauce. “He’s working with the ingredients all night, so we knew there was no way to keep a white vest clean.”

The long sleeves were also counterintuitive, but Calleo told the team they isolate his arms from the hot environment and also contribute to keeping him cool, they said.

Matthew Wettergreen made the connection between Rice and Pi Pizza – as a customer  – and felt the vest could serve overheated workers in many environments.

“There is potential for using this solution in areas beyond food trucks, like kitchens or other hot environments with similar constraints,” said Wettergreen, a lecturer and assistant director for rapid prototyping at the OEDK, who advised the team along with Gene Frantz, a professor in the practice of electrical and computer engineering.