Check to see how many mA the 12V DC
output is, and how many Amps the fan is. Depending on the fan, it should or shouldn't be able to run it. If each of the two fans are .14 Amps, and the output of the 12V adaptor is around 500 mA, you will be fine. 1000 mA = 1 A.
My 12V DC
output is 1500 mA (or 1.5A). Each one of my fans are .14A (or 140mA). So, do the math... 140 mA + 140 + 140 + 140 = 560. My power adaptor should be just fine!
I could wire 120mm fans on there too, but I'll wait to see how efficient these are, and how loud they get. All of the (+) to (+) and (-) to (-) for wiring.