Airtight rooms and the motion of air in them.

air would cease to exist, eventually.

what if this was a simple little stand fan blowing air around, like one someone would use on a hot day to cool thenselves off, and it was left on before the doors of an airtight room were shut. Would it just blow around what ever air was in the airtight room or would in eventually build pressure in that room?

The fan wouldn't raise the overall airpressure in the room; the volume of air in the enclosure will not be affected.

It would get hot.

it would get cold-entrophy.

what do you mean it would get hot? and if so, would the fan over-heat? What my concern is - is that it might overheat and cause a fire. I am unable to get back into this room until Tuesday Morning because this airtight room has a time lock on it. Should I be worried about the fan overheating and maybe shorting out or sparking and causing a fire and if it did cause a fire - could the fire burn very long with what little oxygen must be in this airtight room?

No, I meant the air in the room would get hot. Without outside air to circulate out the hot air, the air in the room will begin to heat rather than cool. At least, that's what I think.

good, so then I really shouldn't have anything to worry about over the holiday weekend. Thanks because I was beginning to wonder if maybe I was going to have to call a tech. out on this holiday weekend to open the time lock doors and man I know that would cost an arm and a leg but it was that are worry that I would have a fire on my hands. Thanks again,

Just to keep you worried, unattended electric appliances are a leading cause of structure fires.
Enjoy your holiday.

In an airtight room, the fire shouldn't burn very long - until you open the door, in which case you should move the other direction as fast as possible.

LOL thanks, and thanks for being able to read my very bad writing and grammar in last reply... Happy Holidays All

Energy is input into the room. Kinetic energy is converted to heat by air friction. May warm up by a few degrees if walls are insulated. Then again the heat loss thru the walls and windows at this time of year may not result in any heat gain. A friend kept a fan running continuously for month till the brushes were worn out. If there is no lint build-up near friction areas you can rest easy as a few days of a fan running continuously will not do anything except run up your electricity bill.

You'd likely get chaotic convention currents due to turbulence.

Most fans on AC use induction motors--no brushes.

Watching smoke traced eddy currents are one of my favorite physical examples of Mandelbrot plots, chaos within bounds,

Moving air will also pump an incipient fire. To prevent being impinged by backdraft phenomena, always feel the door--if it is very hot do not open.

Rap

The only source of energy for the air to heat up would be the fan, but, in fact, the room would radiate energy outwards to try to keep itself in thermal equilibrium with whatever is outside of it, presumably just the world, so even if it were very well insulated, I doubt that the mechanism of a fan could create heat as rapidly as, say, an oven can.

The fan would assist in keeping the room cooler by evenly (chaos aside) distributing the internal temperature across all 6 walls which would allow faster transfer of energy to the outside due to the greater surface area involved.