I'm building a custom case for my computer - how can I adequately cool it?

I'm building a small form-factor PC with a custom case, and the computer components are very close to each other (such as the laptop hard drive and the heatsinks). I have two 40 mm fans, and I am unsure how to place them for maximum effect.





Would it be better to have one fan pulling air in and another on the other side pushing it out, or should I have both fans pushing the air out one side and vents allowing air in the other side? Which would cool best and why?





Thank you in advance for your help.I'm building a custom case for my computer - how can I adequately cool it?
If you are going to build your own CPU case you need to pay attention to proper airflow. Front to back and bottom to top.





Basic PC cooling config:


1. Power supply fan (internal). Which if placed on top rear of unit could draw some air up and out of unit.


2. CPU fan. On some units like Dell they have a custom enclose to draw all CPU heat out the back instead of all around where it has to be removed using the case fan. Notebooks / Laptops use combination heat sink and custom fan enclosures to cool the CPU and draw heat from the rest of the laptop.


3. Case fan. Draw heat out the back of the unit


4. Ventilation holes. Strategically placed to ensure air flow. There are many holes on the front Chassis of a PC for that reason. There also may be ventilation holes on the bottom side for airflow to expansion cards.


5. You can also maximize ventilation further by using round cables. Such as round SATA cables.





Generally intake is done passively. This also reduces noise this way. If you decide for a more open cage style chassis like the Antec 900 airflow issues are reduced and you are just trying to blow away the heat than intake fans are probably better but the problem with this design is dust and little bit more noise.





40mm is small I would make them both exhaust fans.


I'm building a custom case for my computer - how can I adequately cool it?
The best placement for fans is to have one on the bottom front of the case drawing air in, and one on the back near the top exhausting air out. This creates a sort of wind tunnel effect in the case, and since heat rises, the back fan will be removing the hot air from the case. Try to keep the amount of air being drawn in and the amount of air being exhausted out close to each other.
the better your airflow, the better your computer can cool itself.





for maximum low temperatures, i would make sure the wiring is neat and out of the way. that way, air can move more easily. also if possible, use a good thermal paste for your processor, such as Artic Silver.





as for fan placement, I would have 1 intake and 1 outtake. Fresh cool air comes in and hot stale air goes out.





with that done, your SFF case should remain sufficiently cool
Great start a 40mm fan. I have a Thermaltake 500watt with that fan; Ithink it blows down. I only have that one and two 92mm stacked in the back to quiet them and provide ambient cooling all through the ATX case. This Power Supply is for a taller tower (BTX).
heres one. its cheap and works great. use one of those summer fans, thatll bring the heat down, but seriosuly maybe buy a liquid cooling system or Zalmon heatsinks and fans. Heard those work nicely.
Cases usually have holes which you place the fans.





that should be good enough.