I have several Antec cases myself and apart from the big (200?) mm fan on top of the P180 all fans were noisy and needed replacement. Also the fans had no control option apart from a hi/lo switch and no option to connect them to the motherboard fan headers or to a fan controller. Consequently I've replaced all the stock Antec fans except the big one and connected them to a fan controller or the mainboard fan headers. Even at the low setting they ran too fast and too much noise. Contrary to common belief case fans don't have to run very high (for normal pc's, heavy overclockers excluded). You need a draft of fresh air and as long as the warm air gets out its good. Often the lowest speed of around 600rpm for 120mm fans is enough to accomplish that. Just make sure the air flow doesn't get disrupted (cable management!!). I do overclock my cpu (i7 2600K@4.8Ghz air cooled), I have (had) 5 harddisks and a GTX580 overclocked. 2 exhaust fans and 2 inlet fans at 600rpm is all I need, CPU fan ramps up under load but it makes hardly any difference if I turn up my case fans (if I turn them off it DOES make a difference
).
With no addon videocard and that noctua on that stock cpu, I think you're safe to initially try without the extra fans. I don't know what kind of harddisks you will put in that case but in the Antec the drive bays are positioned in font of the inlet. The fans on the top/back will/should create sufficient draft through the drive bays.
If I were you I would try without extra fans and (what I always do with a new system) perform a controlled load test. In your case this would include heavy copy jobs over all disks to produce maximum heat. Using hardware monitors keep track of the disk temperatures. Temperatures often seem stable after 20 minutes but often after 50 or 60 minutes it will rise again, sometimes causing a chain reaction if other temperatures are near their max (but since you're not overclocking and don't have an addon videocard, this should not affect you). Consult the harddisk manufacturer websites to be sure (or ask Glynor
) but I think max temps are 60 degrees, safe continuous operating temps are between 40-45 degrees for harddisks. An occasional peak in temperature should not be an issue so long as it doesn't stay high. Actually I believe too low temperatures on harddisk is worse than running on high temperatures (for bearings and lubrication).
The case should have room for fans in the front of the drive bays, so if during those tests you see the temperatures getting too high, you can install extra fans.
I'm not sure how many fan headers that board has but if you need to control more than 2 fans (not counting CPU fan) you may want to consider a fan controller.
This may be a no-brainer, but check if all your fans are blowing in the correct direction. CPU fan should blow through the fans of the heat spreader (not suck air out of it), top and rear case fans should suck air out of the case (exhaust) and fans in front should feed fresh air to the case. The PSU fan should be an exhaust as well and blow out. You can easily check with a sheet of paper and cover the opening. An incorrect fan setup can completely mess up cooling.