Step 3: Soldering and Glueing
Once you are done soldering, determine which way your fan blows air by looking for a small arrow icon on its side or by plugging in a battery to power the fan. Next, glue the fan by its four corners to one of the two large holes you cut in the case so that it blows air out the other large hole. This way, the fan can suck air into the case and blow it through the carbon filter and out.
After the fan is firmly glued in place, attach a 9v battery to the snap and put a dab of super glue on the top of the snap. Make sure to have the battery pushed through its hole in the case, and push the top of the snap onto the side of the fan so that it is glued in place. The reason why you should glue the snap in place while the battery is attached to it is so that the snap is positioned correctly on the fan. If you glue on the snap without using the battery as a guide, you may not be able to connect the battery to it through the battery's hole on the case. Wait for the glue to dry, and then remove the battery.