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Imagine I have room that is very hot and it is colder outside. I want to cool it down using a fan.

Scenario 1

There is only one door. I have one fan.

Where should I put it and which way should it blow?

Room with a door

Scenario 2

I have two doors, one on each end. I still only have one fan.

Room with two doors

Scenario 3

Same as scenario 2, but I now have multiple fans.

For convenience, it is fine to assume that the room is a cuboid and that the fan emits no heat.

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closed as too localized by David Z Dec 3 '12 at 18:46

This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.

A room with no windows very convenient – Argus Dec 3 '12 at 18:33
Hi luispedro, and welcome to Physics Stack Exchange! As specified in our homework policy and FAQ, this is a site for conceptual physics questions, not a place to get people to solve problems for you. If you'd like to edit this question to show what you've tried and what concept you got stuck on, I'll be happy to reopen it. – David Z Dec 3 '12 at 18:47
@Argus "first, assume the cow is a sphere..." – McGarnagle Dec 3 '12 at 18:49
@DavidZaslavsky This is not my homework. – luispedro Dec 3 '12 at 18:55
I will make my answer into a comment. The idea is to push air into the room, better with a centrifugal fan, , which draws air efficiently, placed at the door. If it is the usual table fan which displaces air in front of it, it should be a bit outside the doors and aimed at the doors to push cool air in. – anna v Dec 3 '12 at 19:00