120mm Fans and Airflow

[achilles]

Ok I just picked up another 120mm Fan for my Antec SLK3700 midtower
and when I first installed it my temps were around 45 degrees C (using MBM5) now about twenty minutes later they've dropped to 38-39 and I'm wondering do Fan's have a burn in period that they take to warm up and really get spinning? also before I installed the second 120mm the temps were a constant 38 weird no? I'm gonna try switching the newer fan to the back as it seems to move less air than the older one. and it makes more sence to me to blow in more cold air than remove hot air?

EDIT: in my old case the same gear was running at 35 constant at full load with less cooling (one 80mm coolermaster CPU fan and the 80mm fan in the 250W PSU) the new case has thicker aluminum construction and a 350W PSU with 2 80 mm fans in it and it run hotter does the extra 100w make that much of a difference.

[silenze]

No burn-in period for fans.

Temps are always a little high when you boot cause you've just put stress on the system.. they always simmer down a little after everything is loaded. (Booting windows.)

You want to try and move an equal amount of air in and out.. otherwise you'll end up with turbulence of warm/cool air mixed all over and that's not really what you're after.. want it to flow through the case.. also could end up with air coming OUT of a fan that's blowing in, see what I'm saying? (Long term that resistance can burn up fan motors.)

Overall ambient temperature is the result of all the hardware in your case, so yeah.

[achilles]

Thanks much Silenze