# Fan and cold air

## Main Question or Discussion Point

I am trying to figure out how to get cool air. Say, if I have a fan and ice cubes. Should the ice cubes be in front of the fan(air blowing at them) or back of the fan (fan sucking).
When I did it, I couldn't feel the difference.

## Answers and Replies

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russ_watters
Mentor
They should be in front of the fan, but you probably won't get the air much cooler that way. There is no efficient way to get the air to blow through the ice cubes.

mgb_phys
Science Advisor
Homework Helper
If you are trying to cool a room (rather than work out a physics problem) lookup swamp-cooler

russ_watters
Mentor
...depending on your climate, a swamp cooler might not be a viable option. It is only helpful in dry climates.

Russ, why should they be in front? Air hits them and cools down?
Wouldn't the fan suck colder air if they were placed in the back.

russ_watters
Mentor
Russ, why should they be in front? Air hits them and cools down?
Wouldn't the fan suck colder air if they were placed in the back.
A fan will push a pretty coherent stream of air in front of it, but pull from a diffuse area behind it. So if you want to ensure the air is actually passing over the ice, you need to put it in front (unless you use a duct).

A fan will push a pretty coherent stream of air in front of it, but pull from a diffuse area behind it. So if you want to ensure the air is actually passing over the ice, you need to put it in front (unless you use a duct).
That makes sense!
I might also offer that if the ice cubes are put behind the fan, that there is a possibility of drawing in melted water drops large enough to short-out the fan.

russ, that makes lot of sense.
Palladin, thanks for the warning. I don't think my fan is that powerful, it is still a possibility.
It would be a cool way to destroy a fan.