6/3     Hello.  Is it more efficient to dispatch the heat by turning
        the fan towards the door/window or towards the room?
        \_ "Dispatch" heat?
           \_ All right, I couldn't think of a better word.  What do
              you recommend?  "Get the hot air out of the room"?
              \_ Dissipate. Yeah, I was just being an ass.
                 \_ I like dispatch better. !op
                        \_ I would have said "remove", but "dispatch"
                           certainly also seems correct to me.  Behold this
                           definition of dispatch:
                        3 : to dispose of (as a task) rapidly or efficiently
        \_ Do you have two windows?
           \_ No, just one.  So it doesn't make a difference?
              \_ He's suggesting cross-ventalation.  The best way to lose
                 heat if it's hotter inside than out is to move the air
                 in one opening (e.g. a window) and out another (e.g. a
                 second window or a door).  If you don't have the second
                 opening, outside-in is usually marginally better,
                 depending on the exact shape of your space.
                 \_ how would one formally proof that outside-in is
                    marginally more efficient?
                    \_ good luck with that. it's a nice, messy
                       fluid-mixing problem best addressed with
                       computational fluid dynamics. in practice,
                       you want to push cool air in at the bottom of
                       the opening and warm air out at the top to
                       reinforce normal convection.
                        \_ Yes, that is what I concluded by considering
                           normal convection, but it is nice to know this
                           has been proven.
                           \_ not really proven.  demonstrable for many
                              parameters of room shape, etc. as suggested
                              by a different poster above.