Voltage required to run fan at 6000RPM

kl31

New Member
this isn't necessarily computer related, but since i'm using computer parts, might as well ask here

i have a car with a very small two seater cabin, and while the AC works, it tends to cause the engine to overheat on very hot days. I intend on building a separate cooling system like the icebox evaporative coolers on the interwebs, except i want to pump ice cold water from a ice box reservoir into a 360mm radiator, and use fans to draw in the warm air to cool it down. I intend to use 3x 120mm fans.

my main concern is that at 12v, the fan won't spin fast enough to provide adequate air flow through the radiator to cool the car. Cooler Master advertises their fan to move about 70cfm of air at max RPM, and with 3 of them moving 210cfm of air, that should be more than enough to cool the car Apparently, max rpm is at 6000RPM. At what voltage do i need to run it at to achieve that speed? noise is of absolutely no concern. I was thinking about running 2x 12v lead acid batteries in series to push 24v.

Also, since i don't intend to run these fans for hours and hours at at time (i pretty much have my computer running 24/7), lifespan is really of no great concern to me. these fans are cheap, and they are easily replaced, but i would like to get a very rough estimate on how long they would last with 24v driving them.

Thanks.
 
this isn't necessarily computer related, but since i'm using computer parts, might as well ask here

i have a car with a very small two seater cabin, and while the AC works, it tends to cause the engine to overheat on very hot days. I intend on building a separate cooling system like the icebox evaporative coolers on the interwebs, except i want to pump ice cold water from a ice box reservoir into a 360mm radiator, and use fans to draw in the warm air to cool it down. I intend to use 3x 120mm fans.

my main concern is that at 12v, the fan won't spin fast enough to provide adequate air flow through the radiator to cool the car. Cooler Master advertises their fan to move about 70cfm of air at max RPM, and with 3 of them moving 210cfm of air, that should be more than enough to cool the car Apparently, max rpm is at 6000RPM. At what voltage do i need to run it at to achieve that speed? noise is of absolutely no concern. I was thinking about running 2x 12v lead acid batteries in series to push 24v.

Also, since i don't intend to run these fans for hours and hours at at time (i pretty much have my computer running 24/7), lifespan is really of no great concern to me. these fans are cheap, and they are easily replaced, but i would like to get a very rough estimate on how long they would last with 24v driving them.

Thanks.

why not just buy a better performance radiator and radiator fan for the car and change the coolant for some better stuff, or check/clean your car radiator and check that theres nothing wrong. a couple 120mm fans wont work very well and they wont last very long on 24v. i doubt your car will last long with a pc radiator either lol.
 
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whats the make and model of your car.most cars now have two cooling fans for the radiator.one for normal use and a second that kicks in when you use the ac.if the secondary fan isnt working due to temp sensor or fan failure etc you can be assured it will overheat during the hot days.i really think your are overthinking this one and recommend fixing the overheating problem with the aid of a good mechanic. ive pulled wrenches for 35 years and have seen this happen numerous times.it can be fixed.
 
I'm not trying to cool the engine with a PC radiator as tylerjrb implies. "I doubt your car will last long with a PC radiator anyways". Good god that would be stupid. And no, i can't just buy a better radiator.

I just want to cool the cabin if it wasn't clear in the original post. I don't see why pulling 210CFM of air through a cold radiator wouldn't cool the interior of the car.

Aldan: Its a 1982 DeLorean. Car doesn't overheat as long as i don't use AC.
 
Dont see why instead of going through all this you just don't fix the cars overheating problem. Radiator flush, new thermostat and coolant and cap.
 
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cool old car.if the delorean has electric fans,make sure they both work.if it is a mechanical fan off the waterpump then look for a plugged rad or a bad thermostat.if its a clutch fan check it carefully for wobbling and that it actually spins when the temp rises.imho there is no way you are going to cool that size cabin with the method you are describing.in the long run this may come down to a little maintenance.hope you get it figured out.
 
I assumed that's what you meant, as you said it was overheating. It would be best to do some fault finding, it shouldn't overheat with the ac on. As for cooling the cabin. It is possible but most likely wouldn't work very well as the fans would last a few minutes at 24v, 6000rpm. It would be best to find and fix the problem rather than spend quite a lot of money and time making a radiator/fan cooler which may not work.
 
There's no problem with the car. The car doesn't overheat if i don't use the AC. The radiator and radiator fans, as well as temperature gauges all work. The coolant has been replaced. I've done all everything so that the car runs reliably. The problem is that the AC simply places too much stress on an already old system. The car is 30 years old. There's only so much that you can do before you need to find alternative solutions.
 
i'm going to run 3x Delta fans at 12v. That should provide adequate air flow through the radiator to provide cooling in the cabin.
 
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if you dont want to fix it properly you can always add an electric fan to the front of the rad.you can put a manual switch to activate it or add a relay triggered by your ac compressor switch.you would be much better served doing this than what you propose.ive owned old vehicles too and there is no reason they cant be in every bit as good shape as a newer vehicle.
 
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