Refrigerator Vent Holder

thingiverse

This thing is designed to be a cooler for the refrigerator's fins, which helps save energy by cooling them down when they get warm. For a 120mm ventilation system, you'll need to screw the parts together at a distance of 105mm apart. The vent is controlled automatically by a microcontroller that starts it up as soon as the cooling fins start getting hot. Because my build plate only has space for a width of 200mm and a height of 150mm, I had to design the components with those dimensions in mind. You can secure the parts together using 5mm screws, then attach them to your refrigerator's top surface or hang them on the wall using two screws. If you have high units, you can cut out small Styrofoam pieces and place them along the back of the device laterally to direct airflow down to the floor where it exits. I've also included a casing for controlling electronics and files, which makes it easier to build a circuit with an ST6260 microcontroller. You could also design your own circuit using a PIC or Arduino chip - just keep in mind that when the vent is working, the cooling fins on your refrigerator get even colder, so you'll need to program the microprocessor to turn off the fan at a certain point or adjust its rotation speed to maintain a temperature around 5 degrees above room temperature. My circuit with the ST microcontroller adjusts the switch-on value every few minutes based on the current room temperature. To prevent accidental contact with the vent, you could attach a cover like one from Mighty Nozzle.