Air pressure equilibrium

[skogkatt007]

I'm wondering something. Is it possible to, by means of a strong fan or maybe a circulating fan, or a whirling fan, to maintain maximum cooling in an air conditioned room. The room isn't very big, say 10' by 12'. Here's the clincher. A large window needs to be opened. All the time. No sense in explaining why.

I read years ago that the atx computer power supply spec mandated that fans pull heat out of the case instead of pulling air in. The reason is so the case would be pressurized, and (presumably) keep dust out. But that seems backwards to me. You pressurize by blowing into the case (or push air around inside it). And possibly having a bigger inlet then outlet? Does any of that make sense? Fluid mechanics is weird I know.

I suppose I could just try something. Obviously a fan blowing at someone (or something) seems to lower it's temperature no matter if there is an ac or not. But to achieve equilibrium, where hot air that would otherwise enter and mix with cool air, would be kept at bay, is what I'd like to achieve.

 

[markba633csi]

Are we talking about a room or a computer enclosure? There are both differences and similarities in terms of airflow.
Plus, a desktop computer enclosure is usually a box within a box, with fans both pushing and pulling

 

[strantor]

Your air conditioned room isn't quite the same as a PC case because it's air conditioned. You would not want the fan to blow air into or out of the room; you wouldn't want any pressure differential at all. if you're blowing air out, that's cold air that you want to keep in. If you're blowing air in, that's hot air that you want to keep out. You would want to only circulate the air that is already in the room, and minimize (by optimizing the fan's direction) any possibility of the fan contributing to air exchange between inside and outside.

 

[RJSakowski]

Your thinking regarding the pressure within a computer enclosure is correct. The cooling effect of moving air is primarily due to evqporation of moisture on the skin. There is a secondary effect as moving air promotes heat transfer by convection whereas still heat transfer is primarily by radiation with a small amount due to conduction (small because the thermal conductivity of air is low).

In an enclosed room with no circulation of air, hot air will rise and colder air sink to the floor. Depending upon where you are situated in the room, you may see an advantage to circulating the air. Air coming from an A/C unit will also be drier than ambient air and directing the air flow towards one will aid in cooling.

 

[RaisedByWolves]

Nature abhors a vacuum, remember this.


Due to this fact It’s something like 3X easier/more efficient to have a fan pull air out of an enclosure than it is to push it in.

Other than that you need to employ a heat exchanger vent for your purposes.