Well guys I've been pondering building my own pc case for a while and I'm asking questions and looking for feedback. I plan on using acrylic and perhaps some aluminum. I might purchase a motherboard tray and hard drive enclosure. My idea is to have airflow over the entirety of the motherboard and components; fans spanning the length of the motherboard, both intake and exhaust. I've made a shitty diagram to show what I mean. I was just wondering if there could be any negative effects of this design (cause you don't ever see it). I understand dust could be a problem but I don't mind cleaning regularly, I just want optimal airflow over my components. I personally like the idea of 'design 2' more because of the idea that hot air rises.
There isn't much benefit to having both intake and exhaust fans. It's not as if the airflow doubles. The input fan is still only moving xxx CFM of air and the exhaust fan is still only moving xxx CFM of air. The benefit is that it increases the static pressure capability of the fans (meaning the air could be forced through the case at a higher pressure, such as in a server where the heatsink fins are very close together). Mostly you will just increase cost, energy usage, and noise level without improving the temperature or life of any components. Personally I am a fan of negative pressure systems (exhaust fans only) as I feel they keep the air moving the easiest with quiet, low-RPM fans like the Noctuas. I also like design #2 for the reason you state. Natural convection will help with the cooling.
Negative pressure systems can bring in air through unwanted places like optical drives. My current case has one 120mm intake fan in the front, two 120mm intake fans on the side panel, and one 120mm exhaust fan. The airflow is actually pretty bad. After just three minutes of prime95 my CPU is at 80+ degrees C. I'm not a fan of side panel fans, I believe they disrupt the airflow. PC airflow and heat – a cooling guide « Icrontic Tech That article is somewhat of a 'study' that supports your idea. The best temps are with a top/rear exhaust set up, but they don't have anything like a bottom to top airflow so my idea hasn't been tested. I would love to see if anyone has done something like this...
cool that you wanna build one yourself, but why go thru the trouble when you can buy one for the same price..? Ive done every setup possible with fans and negative always cools better. atm i got something like design 2 but my psu is mounted on the bottom, takes some heat away from my graphic cards. Also i dont have a fan on the bottom just a slot for a 120mm with a filter, its gets clogged with dust quite fast.
The reason I would go through the trouble is to make it the way I want it, not to buy something prefabricated. I enjoy the idea of modding, as well. I can design it to be way cooler than any store bought case. Would you mind linking me to the case you are using with the 120mm slot on the bottom?
Heres the case i got currently. Was a awesome price for what you get. http://www.newegg.com/Product/Image...20mm Fan, 1x Top 120mm Fan, 1x Rear 120mm Fan The 5th picture shows the bottom 120mm slot w/filter. I have 2x120mm top,120mm rear exhuast, 120mm front intake and the 120mm bottom intake uses a filter which is pretty dusty every time i clean it(2week+/-). The only thing i changed on it was cutting out the grill on the top 2x120mm exhaust fans. Also the front is lined with a filter material that stops dust.