There been a number of us that of used computer case fans in place of a Fantastic Fan And when I first started doing this I used two 80 mm Antec three speed case fans. I am in the process of cleaning off my desk and came across the readings I got when I used the ammeter to figure out what they actually draw. Our experiences that even under the hottest conditions we seldom have them on more than the medium speed. At night mostly they are on low speed and in some cases only one is needed. I used a DPD T switch which allows me to select either both fans operating at the same time or one fan only.
These are for 80 mm fans. On low they draw .15 A on medium they draw .26 A and on high they draw .39 A.