Refrigerator Vent Holder

This thing is a vent holder to cool the refrigerator cooling fins. I can save power with this thing. For 120mm-Vent, screw distance is 105mm. The vent is driven by mikrocontrolled automatic who is starting the vent when the coling fins get warm.I have add different dimensions because my build plate have only 200mm wide and 150mm height. The parts can fix with 5mm screws to get a 50cm-Tool and put it onto the refrigerator top and fix it on the wall with two screws. At high Units you can cut out small styropor parts and put it at the back side laterally to lead the air on all the fins to the floor where the air get out.
I have added a casing for control electronicand files to build the electronic with a ST6260 micro. You can also build a own circuit for example with a PIC or an Arduino :-) But think about that the cooling fins from the refrigerator get lower temperature when the vent works, so you must program the µP either with a fixed timer to turn off the vent or, like my circuit with the ST, regulate down the vent rotation to hold the fin temperature to a value about 5° over room temperature. My circuit adapt the switch on value to the room temperature all few minutes. To prevent touchdanger at the vent you can add a Vent-Cover like a one from mightynozzle.