Could anybody explain to me if I open two windows in my home, when there isn’t any wind outside, why a cross draft occurs and would there ever be an instance where a cross draft couldnt happen even if its windy?
Thanks so much!
In: 3
As for the second part of the question, it may be possible that a U-shape or some peculiar house could be designed in such a way to minimize draft and keep even pressure to prevent wind
…but highly unlikely due to nature’s desire to move instead of stay still.
So I don’t know how it could be possible but I wouldn’t be in shock if a mathematician figured it out.
In addition to what’s already been mentioned, it’s very rare for there not to be any wind at all. And even 1-2 m/s, which feels close to nothing, will create a pressure difference between two sides of the house which can translate into more wind through a small opening.
In addition to what’s already been mentioned, it’s very rare for there not to be any wind at all. And even 1-2 m/s, which feels close to nothing, will create a pressure difference between two sides of the house which can translate into more wind through a small opening.
Also keep in mind:
* Any wind hitting a face of the house with a window either had to go through or around the house, whichever is easier. That can cause a disproportionately large draft compared to wind speed depending on the shape of the house.
* Any wind blowing past a sheltered window will create a negative pressure, pulling air out of the house.
The combination of these two effects on opposite sides of the house will pull air through the house very efficiently.
For the same reason that cold air seems to blow in through doors and windows on a still winter day.
Convection
The inside of your house isn’t the same temperature as the outside and therefore the differing densities of the inner and outer air will begin to move in an attempt to settle out with the cool air on the bottom and the warm air on top.
If you have access to an IR camera this is a really neat effect that’s visible on the walls when the different temperature air begins to stratify inside the house.