Woods, I don't follow . . .
First I'd like to compliment your attention to detail, fine craftsman and skill.
OK, . . . I understand heat rises and all that, science 101. Are you telling me/us, if you put a thermometer inside your case it is the EXACT-SAME temperature as ambient room temp . . . ??
Stay with me here: If a closed area like your case, is said to be "stilll," heat must be present somewhere in the room to cause the air to rise and circulate, so the air is not still. OK, now, if heat IS present then you have circulation. However, if there is NO heat then the air is still and won't circulate.
I'm not a Thermodynamics engineer and maybe I'm confused, but I fail to grasp the concept of how your case contains warm components causing circulation in your case from heat rising and inside your case be the same as ambitent room temp. Way I see it, if both temps were the same then there would be no circulation and that isn't what you say here because you say heat exits the case. "Well I have vents built into my case at the top to allow for the heat to exit the case and not build up."
You catching my drift here? If the case and room were the same the air would not rise and exit the case because there would be no heat present (warmer than room temp) inside the case. Therefore, for heat to exit the top of your case the air inside the case must be warmer than ambient room temp.
I'm going to bed. Nite-nite. OldBird