Switch on case fan for 12V--7V--OFF... good or bad?

[WAZ]

I was thinking of putting a switch on my 120mm case fan. It's the only fan in my system (besides the ones on my power supply and Taisol cpu cooler)... it's the exhaust fan on the back. But it's 120mm, so it's fairly loud. Not unbearable, by any means, but pretty buff. I know that a switch that lets me switch it from its current 12V down to 7V or OFF would help the noise, but is it bad to do this? Will case heat build up too much if I turn the fan down or off? I have a 1.2 GHz T-bird, GeForce2 GTS, several more components, etc, so it can get kinda warm in there. When do I KNOW it will be safe to have the fan on 7V or off, without worrying that anything will overheat?

 

[jsbush]

I think it would be ok, running it at 7v while your just chatting or surfing the web. When you start to play a game you can switch it up to 12v just to keep the temp lower.

 

[LYHTSPD]

hey man... i just built a baybus that does exactly what you are talking about! if you have a temp monitor, watch it when you have the fans at 7 volts... if it gets too hot doing certain things (playing games) then crank the voltage up to 12 volts. ill post some pics if you want me to...