Opinions on fans blowing or sucking?
10-29-2008, 06:05 AM
#31
the heat you were speaking of Drift 101 generated from the pressure is created from a compression ratio these fans do not have any power by design once the preesure becomes just a little bit high they stop moving air because they dont have enough power to exceed theyr very small compression ratio so small its rated in static pressure not even psi
now a air compressor is designed more for high compression and low volume this is when the friction you speak of generates heat your intake side is atmospheric pressure while you output side is 100 plus psi like 7 atmospheres if I remember atmospheric pressure is like 14-15 psi I think therefore the heat is created trying to squeeze all that into a can
a whole nother subject of this I would be interested is do these fans under the body change the aerodynamics of the body
now a air compressor is designed more for high compression and low volume this is when the friction you speak of generates heat your intake side is atmospheric pressure while you output side is 100 plus psi like 7 atmospheres if I remember atmospheric pressure is like 14-15 psi I think therefore the heat is created trying to squeeze all that into a can
a whole nother subject of this I would be interested is do these fans under the body change the aerodynamics of the body
10-29-2008, 06:51 AM
#32
Tech Apprentice
I prefer sucking rather than blowing air on to ESC. Once I nav esc which always were shutting down dou to overheating. I mounted fan to blow, then it was fried in 5 min run shut down after 4 minutes, but sucking out the air got me almost 7 minutes of runtime. Blowing is better on one desired distant object.
10-29-2008, 07:48 PM
#33
Tech Elite
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She's gone from suck to blow!
Sorry, could not resist the urge to quote Spaceballs: The Movie.
10-30-2008, 09:42 AM
#35
Why do most companies want there fans to blow on to the heat sink whether it be on an esc or on the motor? Because when it is blowing on it this creates a higher pressure and with that becomes heat right? so with sucking just the fact of that it is creating low pressure it will help with cooling! What do you think?
This was a days discussion in my tent with my dad and a racing buddy
This was a days discussion in my tent with my dad and a racing buddy
Take a peak at this http://www.coolcanfan.com
Cheers Malc
10-30-2008, 02:00 PM
#36
You want to maximize the air flow over the component to be cooled.From an enclosed area you can exhaust warm air and draw in cooler ambient air. This is how a computer case exhaust fan works. If you have an open area around the item being cooled you direct the flow by blowing.
And dont forget that you dont suck the air. You create a delta pressure and air tries to equalize the pressure by flowing into the other side.
And dont forget that you dont suck the air. You create a delta pressure and air tries to equalize the pressure by flowing into the other side.
11-01-2008, 09:19 AM
#37
Just thought i would chime in tha subject.
Look at fans in cars, many have electric ones that reside behind the radiator. the reason for thrm sucking air rather than blowing is that the heat build up in the tight space can cause the fan just to spin and NOT blow any air though. but placing it where the heat is extracted into cooler air that the molecules are not pressing back as they are trying to get away from the radiator.
Thus the most efficient way of doing it pullingit away not pushing it on.
Look at fans in cars, many have electric ones that reside behind the radiator. the reason for thrm sucking air rather than blowing is that the heat build up in the tight space can cause the fan just to spin and NOT blow any air though. but placing it where the heat is extracted into cooler air that the molecules are not pressing back as they are trying to get away from the radiator.
Thus the most efficient way of doing it pullingit away not pushing it on.
11-01-2008, 01:06 PM
#40
11-01-2008, 01:10 PM
#41
Tech Initiate
I would said, when we want to cool down a dedicated area of heat source, we use blow. And when we want to cool down a large area, we use suck.
And that's why are most of our fan on the charger and power supply are sucking, while the fan are used to cool down the whole area inside.
As for the computer example may not work here, while we are talking about a cooling system instead of a single fan. Usually, the fan at the front and side, the fan blow, and the fan on the top and at the rear, it suck air out from the computer case.
when I see "pressure create heat", it's true but seems our ESC fan won't create enough pressure to make a difference. But I think of a funny idea from this, blowing fan also creat "thrust" and most of our ESC fan are horizontal. will we create more down froce if we suck air from the heat sink? it create thrust to the top = more down force.
Just joking, It won't make a big difference.
And that's why are most of our fan on the charger and power supply are sucking, while the fan are used to cool down the whole area inside.
As for the computer example may not work here, while we are talking about a cooling system instead of a single fan. Usually, the fan at the front and side, the fan blow, and the fan on the top and at the rear, it suck air out from the computer case.
when I see "pressure create heat", it's true but seems our ESC fan won't create enough pressure to make a difference. But I think of a funny idea from this, blowing fan also creat "thrust" and most of our ESC fan are horizontal. will we create more down froce if we suck air from the heat sink? it create thrust to the top = more down force.
Just joking, It won't make a big difference.
11-01-2008, 01:16 PM
#42
Tech Initiate
11-01-2008, 01:20 PM
#43
Or maybe if we cut a hole in the back of the body and mount a fan there blowing to the outside of the car we can go faster!
and mount one blowing off the top of the car to make it push down harder for more downforce like y'all said!
and mount one blowing off the top of the car to make it push down harder for more downforce like y'all said!
11-01-2008, 01:26 PM
#44
Tech Initiate
11-01-2008, 01:28 PM
#45
Hmm... I might have to go charge up my batteries and do some speed runs... I think I have an old body sitting around somewhere that I can hack at