Originally Posted By: Gokhan
Originally Posted By: nap
Yeah right, have you even bothered to google for the author’s credentials? He retired as Principal Scientist at Philips after a career focused on thermal management of electronic systems.
It's good for him. In that case we are talking about your lack of understanding. The fact remains that the effects of air's heat conductivity are insignificant, as the air convection and heat radiation are the primary mechanisms in electronic cooling and air conduction hardly plays a role. You need to understand that part first before you imagine the insignificant effects as being significant.
With the risk of being called out again on "replying to" myself, as opposed to quoting myself, here is the bottom line on this:
As I said the air is practically an insulator and the air slab between the electronics component and ambient doesn't really conduct heat. However, the question still remains to what happens to the thermal resistance at the junction of the air and heat sink.
Does the thermal resistance at the junction, which is the most critical factor for electronics cooling, decrease with the humidity?
It turns out that the answer is yes, and it does decrease
substantially with the humidity. The reason is what I already explained to you -- this thermal resistance is dictated by the
air convection,
not air conduction, and air convection is improved with higher heat capacity of the humid air. Therefore, humid air substantially cools better as most would know from common sense -- stand with your face against a cold dry wind versus a cold humid wind.
The influence of air humidity on effectiveness of heat-sink work
