What are the basic principles of computer case design?

I want to have a go at building a new computer case for my ATX form factor computer. it's a custom built computer currently in a tower case i want to change it. The main reason is to make it quieter but how can i do this without compromising the heat dissipation? i have a 150mm (thats how far apart the screws are set in opposite corners) fan on the back and a big heat sink and fan on the Pentium 4 Prescott processor.


What materials should i avoid and do you have any recommendations for possible alternative materials. Preferably i would like to make it really interesting, if you have any reference pictures of other mods people have done that would be cool.





Has anyone have any harsh lessons from experience of what i should avoid doing?





Also from what i can tell the main cause of the noise coming from my case is the rush of air, the actual case itself has very little vibration apart from when i put a CD or DVD in the drive.





Thank you in advance for any! help.What are the basic principles of computer case design?
I can help regarding the Thermal aspects of the case design (having done this a few times before proffesionally).





Everyone knows that to keep computer components cool you need 2 elements:


1. Heatsinks (to disapate the heat *increase is surface area*)


2. A ';liquid'; way of removing that disapated heat outside the case (air/water/oil)





Many people have started to experiment with water and oil, but i personally dont trust it, and would stick with air cooling.





Lets start with heat sinks: These can be made of many different materials, but the main two are Aluminium and Copper. Copper is better at disapating heat, due to its properties as a metal. Hence silver and gold are also good fr this, but a little expensive. If you want to disapate heat more efficiently, then use copper heat sinks.





Now yes, you get all these great big heatsinks (like the zalmans etc...) which look really cool, but they take up to much space for a form factor (and they are too noisey) You are better off using a retangular heatsink (remember the more fins there are, and the thinner the fins are, the better the heatsink is at its job. Also the method of creating the fins is also important.





A bonded fin (one which is welded to the base) is not so good. Extruded fins are a bit better. But skiving fins are the best (essentially these are cut into the block of metal, so its properties are least affected). Try looking at www.dynatron-corp.com for some good examples.





So, now you have heatsinks on your components, you need to decide if you want to have lots of little high speed fans or blowers sitting on each one, or whether you leave the little fans off, and go for ';passive'; component cooling. Now thi is normally only advised if you can cool air, then blow it through the case at high speed, and suck it out the other side. but thats noisey and expensive. So i would go for active cooling (but make sure you get low-speed, low noise fans (the bearing used is important but i wont go into bearings today)





NOTE: it is not about how fats the fans spin, it is about how much air they move per second (CFM) A big fan that spins slowly will move more air persecond than a small fan spinning fast.





So get the biggest fans you can.





The more air you move through the case, the better, so make sure you have one sucking air in, and one blowing air out (set them to run at the same speed.) If you have 2 x 12cm fans spinning at less than 1000rpm, then you will hardly even hear the noise they make.





NOTE ON DUST: fans work because the blade cut through the air, and scope it/move it in a direction. If the fan blades are dusty, they will not cut air aswell, and you can decrease the performance by over 50%!!!! Keep your fans clean. Use filters only where absolutely needed.





So, case design... begin by having all your components laid out on a surface (include a PCI graphics card riser) this means you can change the orientation of your graphics card if you need to. Rotates the card port by 90degrees, very handy in a form factor.





Your Motherboard is your basic foot print, so try and fit everything into a case that is the same size as that (and only 12cm wide!!!) Try it, and if you need more space, just do it little by little. 3D modelling is an advantage here. By the way, 12cm is chosen because it is the size of the fans i recommended.





It can be done, i have built a high performance games machine to 240mm x 150mm x 50mm in the past, and had it on near silent running.





As far as material goes, i have only ever used perspex and aluminium.





Good luck.





Message me if you want some other ideas, i can send you some pics of my work.





:o)





J2GWhat are the basic principles of computer case design?
that is a small hole that you are trying to suck air through if it is making more noise than the fan. If you can you could probably cut a hole on the panel that you can remove to work the the inside of the comuter. My ultra case has a hole in the removable panel right over the cpu heatsink that has a grate over it to filter stuff out.
Check out Vadim computers' website. They have some interesting stuff.
just water-cool it. then you wont need a new case. if you really want to make a new one badly though, metal is probably sturdiest.
You can make your case quiet by changing fans to low noise and fitting noise reduction foam inside the case sides. Always remember airflow is the key so fans should suck in air from the front and blow out the back passing over the motherboard etc on the way.