ASHRAE challenges students to design portable refrigeration unit
ASHRAE asked students to literally think outside the box with the association’s new Applied Engineering Challenge. Students were tasked with designing a portable refrigeration unit.
The Applied Engineering Challenge is part of the charge from Presidential Member Tom Watson, who put forth that ASHRAE broaden its horizons by making accessible technology for use in any country, by any person.
The challenge stipulated that students design a refrigeration unit with a holding volume of 1 ft by 1 ft by 1 ft. The unit needed to be capable of transporting small essential cargo, such as food or medicine. The temperature inside the box must be maintained at 25ºF without an external power supply and the device must be able to be assembled anywhere in the world.
The first place Applied Engineering Challenge winners are Brian Kaufman, Nick Leeburg, Tony Lin, and Micah Reich of San Jose University in CA. Their faculty advisor is Nicole Okamoto, Ph.D.
The team chose a simple wooden frame for their freezer unit due to the simplicity of fabrication and availability of the material. As refrigerant, HFC-134a was used for its less detrimental impact to the environment compared to chloroflurocarbons. The freezer uses a swing motor compressor which allows the device to work while in transit, making the freezer more durable and able to handle vibration and changes in orientation. At just 65 lbs, the freezer can easily be carried between two people.
Also critical to the freezer’s design is the solar panel and self-adjustable rack that allows a user to gather the maximum amount of sunlight. The solar panel powers an absorbed glass mat battery, which was chosen for its reliable track record in the solar industry and relative lower cost in relation to cycling life. The battery requires little maintenance and provides increased safety to the user — safety such as drop protection and no spilling of acid if broken.