convection cooling
convection cooling
(OP)
I have a aluminum box that is 19in x 7 in x 11in. inside the box approx 110 watts is being dissipated. the aluminum thinkness is .225in and i was wondering how much heat can the box dissipate by natural convection alone at 25 c, 50C, and 70C.
At ambient i measure 50 C on the hottest portion of the box after about 2 hours and it seems to reach a state of equilibrium. i took a fan at about 100 cfm and sucked the air off the top of the box and the temp dropped to about 35 c in about 30 min box weighs about 50 lbs and has an aluminum motherboard and 44 pwb card mounted vertially inside (not a solid aluminum box). im just looking for a rough number any help is appreciated thanks in advance
ps please dont spam me because i cant seem to figure it out myself
At ambient i measure 50 C on the hottest portion of the box after about 2 hours and it seems to reach a state of equilibrium. i took a fan at about 100 cfm and sucked the air off the top of the box and the temp dropped to about 35 c in about 30 min box weighs about 50 lbs and has an aluminum motherboard and 44 pwb card mounted vertially inside (not a solid aluminum box). im just looking for a rough number any help is appreciated thanks in advance
ps please dont spam me because i cant seem to figure it out myself





RE: convection cooling
TTFN
RE: convection cooling
RE: convection cooling
Additionally, 65C case temperature would be a burn hazard, so you're pretty close to maximum allowable case temperature. Assuming that your ambient was 25C, your temperature coefficient to the hottest external spot is 0.23 deg/W. To the first order, the delta temperature will be the same for different ambient temperatures, so with a 50C ambient, the case temperature will reach 75C, ouch!, and the internal max temperature will reach 95C, which is the limit for extended temperature IC's.
TTFN