Fan noise question

I've never heard of internal bleed from fans, but that's a good question. I think most of the bleed/noise comes from hi frequency electronic components in your CPU, and that's pretty well shielded by the case.

As far as acoustic fan noise, folks here have tons of solutions... everything from quiet fans to CPU enclosures, to putting your CPU in a different room.

My rig is so noisy, I'll probably have to do a combination of all the above. As it stands now, I do as you do--keep the mic as far from the DAW as possible. Also, I use my laptop for recording (Acer laptops have ultra quiet fans), and then I power up my regular computer, "the hair dryer" , to mix & do the rest.

I record almost everything by plugging direct into the soundcard

Is your soundcard internal? If it is, you might get some electronic noise from components inside the case. That's why most soundcards come with breakout boxes where the AD/DA conversion takes place. Some people even say it's smart to keep the breakout box 6' to 12' away from your CPU.

Yup, I think you're right... for most of us, it's a matter of having the fan too close to the mic & getting over-the-air noise. Not many of us have a proper sound booth, so there's often a wisp of fan noise getting on the track. If you put heavy compression on the track, the problem becomes painfully obvious. (Another reason to avoid heavy compression I guess?)

I'm with ya about the heat ...I also turn off the fridge in the next room. More than once, a long recording session has resulted in spoiled leftovers

I'd keep the fans, but you can quiet down the case a little by rubber mounting the fans so it doesn't transfer the noise to the case. I had to do this in my mATX case, because I don't want to lose my fans either.
 
As for me, I'm not concerned with picking the fans up on the mic...surprisingly they don't for me. I've recorded acoustic guitar right in front of it with no bleed.
 
However it is the sound in the backround for me when I'm mixing that bothers me. I have a VERY quiet mixing room, and the room becomes noisy when the computer is on. I like to check mixes at low and mid levels, and the computer makes it hard to hear fine detail.