The fan increases air speed at the centre of the rotor, creating a low pressure zone which then sucks in surrounding air. So it helps to place the fan away from the window (roughly far enough that the wind cone "fits" the opening).
I would have loved to see that video 2 months ago. Thanks for sharing.
I tried to put the same kind of desk fan at the window, one way and then the other, for a few hours, to see if it had any effect. It was a very hot day but colder outside than inside. The building's concrete was likely still radiating the heat from the day before and there was no wind.
I see now that my observation at the time was right: it did nothing to the temperature, and it might have worked better if I had put the fan 1-2 meters away from the window, directing it towards the window. Now, whether the effect would have been significant anyway… we'll have to wait for next summer to know, I guess. I'm not particularly looking forward to it, though.
A 20 or 24" box fan still moves a LOT of air- you should get a decent breeze if you guide the air. the largest mistake I see is forgetting that a fan can't blow if theres no air coming or going- you need openings of equal size (larger is better) between where the fan is and where you want the air to come from/go.
An easy mental model is imaging the air is water. Close a door on a room and it'll fill up and block the hose.
PS: a box fan and a 5" thick MERV13 filter makes a heck of an air filter. 2" likely also will work. MERV13 is great, but some HVAC can't handle it, and it takes a couple passes (term is air exchanges per hour, I think) to capture what HEPA does in a single pass.
Not sure then. Maybe concrete really is too hot. Where I am adobe (clay, not company) buildings have traditionally been used in some areas to even out temperatures (desert region. Too hot in the day, too cold at night).
I'm interested about this for next summer, could you or someone else expand on this / give pointers?
apparently this is the source: https://youtu.be/1L2ef1CP-yw
The fan increases air speed at the centre of the rotor, creating a low pressure zone which then sucks in surrounding air. So it helps to place the fan away from the window (roughly far enough that the wind cone "fits" the opening).
I would have loved to see that video 2 months ago. Thanks for sharing.
I tried to put the same kind of desk fan at the window, one way and then the other, for a few hours, to see if it had any effect. It was a very hot day but colder outside than inside. The building's concrete was likely still radiating the heat from the day before and there was no wind.
I see now that my observation at the time was right: it did nothing to the temperature, and it might have worked better if I had put the fan 1-2 meters away from the window, directing it towards the window. Now, whether the effect would have been significant anyway… we'll have to wait for next summer to know, I guess. I'm not particularly looking forward to it, though.
A 20 or 24" box fan still moves a LOT of air- you should get a decent breeze if you guide the air. the largest mistake I see is forgetting that a fan can't blow if theres no air coming or going- you need openings of equal size (larger is better) between where the fan is and where you want the air to come from/go.
An easy mental model is imaging the air is water. Close a door on a room and it'll fill up and block the hose.
PS: a box fan and a 5" thick MERV13 filter makes a heck of an air filter. 2" likely also will work. MERV13 is great, but some HVAC can't handle it, and it takes a couple passes (term is air exchanges per hour, I think) to capture what HEPA does in a single pass.
Yep, I had all my windows and doors open.
Not sure then. Maybe concrete really is too hot. Where I am adobe (clay, not company) buildings have traditionally been used in some areas to even out temperatures (desert region. Too hot in the day, too cold at night).