how many extra fans can my case hold

Solution
Newegg and you manufacturer's web site will list what can be placed into your case.

I recommend (for a quiet build) one (1) 120mm for each 50 - 75 watts worth of components (75- 100 watts for each 140mm). And keep in mind that air flow on intake fans will be restricted by dust filters and when they get some dust buildup significantly so. To insure positive air pressure inside the case, with a bit of dust you could see flow reduced by as much 30%. Depending on how clean you keep them, I'd suggest from 130 to 150% as many intakes as exhaust; remeber also that your GFX card9s) are blowing air out of your case.

When you have more air being exhausted out by case fans than coming in, inm most case designs, most of the "make up" air...
Newegg and you manufacturer's web site will list what can be placed into your case.

I recommend (for a quiet build) one (1) 120mm for each 50 - 75 watts worth of components (75- 100 watts for each 140mm). And keep in mind that air flow on intake fans will be restricted by dust filters and when they get some dust buildup significantly so. To insure positive air pressure inside the case, with a bit of dust you could see flow reduced by as much 30%. Depending on how clean you keep them, I'd suggest from 130 to 150% as many intakes as exhaust; remeber also that your GFX card9s) are blowing air out of your case.

When you have more air being exhausted out by case fans than coming in, inm most case designs, most of the "make up" air will be sucked in thru the rear case grille and slot grilles. And that air will contain two things you don't want ... dust and much of the heat exhausted by your GFX cards_) and PSU.
 
Solution