This cooler can cool your adapter from about 70℃ to 40℃, which could increase lifespan and lowering electrical resistance.
The cooler can be powered with a usb socket (your laptop, wall socket, game console etc.) or a portable usb powerbank.

Step 1: Why?

I noticed my laptop adapter getting hot, after some heavy use too hot for me to hold it in my hand.
When I thought about it I noticed that some of my other adapters also could get very hot (e.g. my 12v monitor adapter, my laptop adapter and the adapter for my game console).

Almost every adapter is made from plastic which isn't very conductive, so most of the heat can't get out very well. Most adapters are made to survive these conditions, but I don't believe 70℃+ for longer times can be good for any adapter and when it's summer things can only get hotter.

I think by lowering the temperatures of most adapters you can increase the lifespan and lower the electrical resistance.

This is why i made this cooler, it can be connected via usb, so directly to your pc,game console etc. or via an powerbank if the adapter is too far away from any usb socket.

Step 2: Things You Will Need.

The bare minimum you need:
-(laptop) 5v fan
-usb cable (no flat cable)
-2x(hair) elastics(rubber bands)
- electrical tape

You might already have all of these, if not, you can look down below to know where to find/buy them.

Extras:

-Super glue (to secure the elastics)
-Cardboard or double sided tape (If you want some space between your fan blades and the adapter)
-Powerbank (if your usb cable can't reach a usb socket)
-Scissor (if you want to make holes to secure the elastics)
-Heatshrink tubing (for extra isolation)

- Most, laptop coolers work on 5v. So you can salvage one from an old laptop or buy one online like this
- You might have a broken usb cable laying around, or you can buy one (the cheapest one is most likely to be good enough) or buy one online.
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Step 3: Prepare the Usb Fan.

If your fan has a connector you need remove that connector and remove some plastic so the power wires are visible (refer to picture).

We will only need the + and - cable, (+ is most likely to be red and - is most likely to be blue or black, yellow is most likely for data which we don't need so you can cut that cable if you want)

Step 4: Prepare the Usb Cable and Connect to the Fan.

We will only need the usb side from the cable, if you have a micro/mini/etc. usb connector you can cut that piece of so yo only have the usb cable left.

Strip down the cables so you can see the wires ( only do this to the + and - wires, other colors are for data and we don't need these cables)

If you want to add heatshrink tubing do it before you add the wires together!

Connect the +usb to the +fan cable and the -usb to the -fan cable.(refer to picture), twist the wires around for extra durability.

Add some electrical tape to secure and insulate the wires (refer to picture)

If you added heatshrink, make sure it covers the wires and heat it up so the tubing shrinks (best to watch a tutorial if this is your first time!) (refer to picture for result)

Step 5: Add Elastic Bands.

Now we need to add 2 elastic bands.
I used elastic hair bands, but something like a rubber band should work as well.

I made 2 "holes" in the plastic from the fan, I did this while using scissors. (refer to picture)

Next I connected the elastic with a drop of superglue to the fan (refer to picture)

Your fan is now complete!
If your fan does not spin see the next step!

Step 6: Add Some Height. (optinional)

If the blades of your fan reaches the adapter itself (so the blades get stuck and can't move), you need to increase the height of the fan. I did this by adding a few pieces of cardboard.

First we need to cut about 5 pieces of really small cardboard (refer to picture), then we need to glue the cardboard to the casing of the fan (refer to picture)

This should do the trick!