Strange phenomenon with wind and windows?

Question

I live in DC, where it is currently under 60 degrees. However, the heat has been turned on in our dorm rooms, and so it is usually warm in our room. When we want to cool down, we open the window to let air in. However, for days we could not seem to change the temperature of the room; with our windows wide open we still had a warm room. It appeared that no air was coming in from outside. Just today, I noticed that if I left the door to our room (the door to the hallway) open, wind would rush in through the windows, thus cooling the room. I was wondering if anybody had any idea why this is true--I can only think of how air works in a vacuum, but that doesn't seem to apply.

Answer 1

Winds needs currents and draws. If you open a window but the room is closed up, the wind has nowhere to go. You might get cool right by the window but the room needs a draft to pull in the cool air. You created a passage by opening the door. If you want to keep your door closed, get a fan to circulate the cool air from outside to the inside.

Answer 2

If the window is short and wide, the door is closed and no wind outside, then you won't get much convection current (with convection current, warm air goes out through the top half of the window, cool air comes in the bottom half to replace the lost warm air). With the door open, you may get a through draft.
Opening the window isn't the environmentally friendly way of cooling a room, turn the heating down. The room full of warmer air wants to rush out keeping the cooler air from coming in. heat transfer happens by convection, conduction and radiation.
In order for convection (mass movement of air) to happen, the air has to have some place to go. If a window is open, but there is no other way for air to escape the room, then the air won't come in or go out the window. The same thing happens if you try to pour water out of a bottle with a small opening. I am sure you know how turning a Beer-can sideways and punching a hole in the bottom of it in order to chug a beer from a can in under 4 seconds, the same principal applies. You need to get air into the can in order to get liquid out of a small hole.
As one of the basic heat transfer mechanisms, convection involves the transport of energy by means of the motion of the heat transfer medium, in this case the air surrounding the body.
When you open the door your meerly creating a cross ventilation with other open doors window in the building.
Winds needs currents and draws. If you open a window but the room is closed up, the wind has nowhere to go. You might get cool right by the window but the room needs a draft to pull in the cool air. You created a passage by opening the door. If you want to keep your door closed, get a fan to circulate the cool air from outside to the inside.

Answer 3

If the window is short and wide, the door is closed and no wind outside, then you won't get much convection current (with convection current, warm air goes out through the top half of the window, cool air comes in the bottom half to replace the lost warm air). With the door open, you may get a through draft.

Opening the window isn't the environmentally friendly way of cooling a room, turn the heating down!

Answer 4

heat transfer happens by convection, conduction and radiation.
In order for convection (mass movement of air) to happen, the air has to have some place to go. If a window is open, but there is no other way for air to escape the room, then the air won't come in or go out the window. The same thing happens if you try to pour water out of a bottle with a small opening. I am sure you know how turning a Beer-can sideways and punching a hole in the bottom of it in order to chug a beer from a can in under 4 seconds, the same principal applies. You need to get air into the can in order to get liquid out of a small hole.
As one of the basic heat transfer mechanisms, convection involves the transport of energy by means of the motion of the heat transfer medium, in this case the air surrounding the body.

Answer 5

Air will flow high to low pressure, so I think if outside is really calm air will naturally flow from your building to outside pumped by building's heating/vent system. That's probably why you see air rush into your room from hallway. But yea usually some winds push inside through window, but if youre in city, tall buildings there might be funky turbulence outside your window that some how created calm spot. May be way the building was design to keep better insulated or something.

Answer 6

The room full of warmer air wants to rush out keeping the cooler air from coming in. When you open the door your meerly creating a cross ventilation with other open doors window in the building.