I also had the problem of the fan going bad on my Areca 1220 Controller (i have several 1210, 1220).
I attach two pictures, so people can see the model number of the fan.
It says AD0412MB-G70 from Adda Corp, but you cannot simply order this model number!
If you look for the model number on the web or eBay, you will see a fan with 10mm height. But your Areca controller the fan is "flat", it´s mounted about 2 mm higher (because a little bit of plastic is removed on the bottom side) and also the screws from the top are 5mm lower than on the 10mm fan.
It wont fit, it will make everything higher so your controller may collide with the card in the next expansion slot.
In addition to that, you will see fans with this model number with 0.08A and with 0.11A.
I will try to look for the correct one and post a reply here if i found one