Cooling help

[Orb]

I have a coolermaster mystique case with a 550W PSU running an 8800GTX which runs at around 65C at 66% fan speed, although these are normal temperatures I would like to cool the card more to expand its lifetime.

I have one big intake fan ( the case fan i presume ) at the back of the case, the PSU exhaust fan, and the GPU heatsink/CPU stock cooler.

I have 2 drive bays at the front of the computer free & 3 PCI slots free beneath the graphics card ( between the GPU and the soundcard ).

I'm not really sure what fans to install & where.. I've heard an exhaust fan should be used beneath the GPU to propel cool air from the bottom of the case onto it. I've also read that there should be negative air pressure inside the case for best cooling... but i'm not quite sure what this means, enlighten me!

Besides this, I've also read that filtering the fans or using a dust screen prevents dust being sucked in through the fans while providing the same amount of air cooling. Also what is the best method of removing accumulating dust inside the computer.. compressed air sprays?

Any thoughts/opinions as to what I should install & where as well as all the other questions ? Cost is not really an issue as long as the total is not over £50 and the fans are quiet, provide very good cooling, filter dust properly & use very little power.

Thanks for your time & consideration.

[Whiternoise]

Compressed air cans are good for doing a good ole cleanout

I would recommend putting a fan in at the front of the case (if its not too obstructed by the front panel), get yourself a 120mm akasa or sharkoon job if you want quiet (or SilenX, but they're ridiculously expensive and people have mixed views about them). If you're really into it, then cut yourself a blowhole!

The stock cooler for the CPU is probably a big culprit. Get yourself a new cooler (again, akasa has served me well in the past)

The thing about negative pressure i don't really get either, i just switch the fans round, monitor the temperature and then leave them on the way that's coolest.

Cable tidying is a great way of improving airflow, and it's cost effective.

Airflow wise, you want it so that air comes in, flows across the CPU cooler, across the GPU intake and then out. Most people have in at the front, and out at the back/top.

Costwise:

1 120mm fan ~£12
Cable Tidying ~£8
CPU Heatsink (Akasa EVO120) ~£30
(or)
Zalman Super Flower ~£19

[Orb]

I forgot to mention, there is a large fan at the front of the case covered by a mesh where dust collects.

The CPU stock cooler seems to be doing fine atm.. 38C on idle, about 45 on load. that's decent enough right? System temp is 37-39C normal, around 45 load

[Whiternoise]

Temps seem fine , the chassis seems a tad warm though.

(just to clarify, i meant in noise terms, your cpu fan is probably the most noticeable component)