An Air Rack for Rink Mittens

A Winter Rink Challenge

Snow piles lined the streets outside the town ice rink. Inside, skaters left damp mittens on a rack in the lobby. The rink's winter club wanted to build a small device that would move room air toward the mitten spaces. The device would not include a heater. First, the club needed a way to check where its moving air reached.

The club hung six equal paper ribbons, one at each empty mitten space. During each ten-second test, students counted the ribbons that fluttered for the entire test. A successful design had to move at least five ribbons. The complete device also had to have a mass of no more than 350 grams so it could be carried easily.

Available parts included a holder for two AA batteries, wires, a switch, a small motor, guarded plastic fan blades, and cardboard air guides. Electricity from the battery pack could run the motor. The motor's shaft could turn the attached blades. The air guide surrounded the fan's outlet and helped direct its airflow. Paper ribbons were test tools, not parts that powered the device.

An adult checked every connection and secured each fan guard. Students kept fingers and loose clothing away from the fan. They tested in the dry lobby, away from the ice and wet mittens. Every trial used the same rack, ribbons, motor, blade set, and type of fresh batteries. Tests lasted ten seconds. Students changed the fan's distance from the rack or the air guide, as shown in their design log. They recorded both the ribbon count and the mass of the complete device. These tests measured airflow reaching the spaces, not how quickly mittens dried.