I thought that case fans were to get hot air out of a box and cool air in the box..and the fans over and in the components were to get the cool air directly on the item.....No box should equal no hot air. I have run with this set up for 5 years now and never had a heat issue. Am I missing something?
Your idea of case fans is only partially correct. Of course, that is what they do, but that isn't all.
One important thing that a good case does is controlling the airflow. I recall the then new dead silent PowerMacs having fans both in front and in the back, connected with tubes that had gaps in certain places on the way to increase the airflow through heat sinks.
Now you might know that hot air moves up. It also moves sideways, but not so fast. If you have your motherboard bolted flat under your table, the CPU cooling has to work upside down, the fan desperately trying to move the air first through the sink and then along the vast table bottom area to the edges. Most likely you have your table along the wall and you're blocking the airflow with your body on the other side. During a prolonged session the same air keeps circulating under your table, getting warmer and warmer... The fact that you haven't had any problems so far only tells that there's enough space under your table to keep your components below critical temperatures. You might be surprised if you compared the temperatures of your components under the desk and then in a well designed case.
