Place the 45 degree PVC fitting on the top if the box, then use a marker to mark the outline and cut-out.

Open the box & use hand tools to cut openings - the plastic is soft and is easy to cut with a drill and hacksaw.

Mount the fan on the inside & route the fan's power plug to the outside of the box.

Mount the 45 degree PVC fitting to the top of the box. You can use silicone or white bathtub calk to hold the fitting in place - silicone (any color) really works best. Blue gasket former, sold at most auto parts stores, does not work well.

The flexible hose does not need any glue - it should fit tight inside the PVC fitting.

If the fan is pushing air out, reverse the wiring and test again. If the fan just hums & does not turn, you bought a AC power supply instead of a DC power supply.

Eric also bought the mating power plug from Radio Shack so that he can unplug & replace the fan later. If you don't buy the power plug then you will need to cut the small connector off the end of the fan power cord before splicing.

Note the cool blue light. This would look nice in a glass front cooler.

Then re-connect the wires in the same direction they were before. If not sure, just wire & test again.

You can see the connector the Eric used on his - this is not necessary but will be convenient if you want to replace the fan later.

The right length should look like this picture, with the hose sitting at least 1/2 way into the beer tower so that friction between the flexible hose, tower insulation and beer lines can hold the hose in place.

If the hose tends to fall out of your beer tower, you can always tape it to the 2 beer lines for suport.

Note: The top of all round beer towers just pops off.

You can tell its there only because of the cool blue light.

One observation that Eric made later - the fan actually cools too well and water condenses on the outside of the tower. But is this really a bad thing?

To prevent this, he has started plugging in the fan only when serving beers from his kegerator.

I believe a better solution would be to wire a cut-off extension cord end or outlet in a box into the thermostat circuit and then to plug the fan power supply into the outlet. If done right, the fan will come on whenever the kegerator turns on. But to do this, you need to understand more about how the kegerator is wired and there are too many brands and models out there to include wiring directions for each one in these instructions.