# Minimum voltage to run 24v fan



## Delgado (Oct 8, 2008)

Hi everyone,

I've ordered a couple of 80mm adda waterproof fans for my viv. These are 24v.
I'm familiar with the concept of undervolting fans and most of the 12v fans in my pc are currently spinning at 5v

Does anyone with experience know if a 24v fan would spin reliably with a similar drop - i.e would I be able to run them at roughly half speed using a 12v adaptor - or would it be better going for 15/ 18v to be on the safe side? It would be great if they'd run off 12v ok as good quality adaptors are much easier to get hold of at a decent price and I seriously don't need all the airflow these fans would give at full speed.

Thank you!


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## pl259 (Feb 27, 2006)

I've run 24V fans at 12V w/o problems. Don't know if yours will work though. If you're worried about ordering the 12V adapter and not having it work, you can order the fans seperate and try them on a car battery first. 

Eric


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## Delgado (Oct 8, 2008)

Thanks for your reply 

As it happens the fans turned up today, much quicker than I expected - all the way from US to UK quicker than most of our internal post at work 

Just tried one of them on a 12v digital radio adaptor and they do indeed spin up just fine. I'm planning to use quite constrictive filters on both sides of each fan:










I think 15v is probably a safe bet to produce enough airflow to compensate, well hopefully anyway..


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## Dancing frogs (Feb 20, 2004)

Just so you know, you can acheive the lowest fan speeds by using a pulse width modulater.
Basicly, it gives brief pulses of the voltage necessary to keep the fan spinning. If you just lower the voltage, the fan will stall.


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## Delgado (Oct 8, 2008)

Yes indeed, the T-balancer in my pc does exactly that - some fans run by pwm and some by voltage decrease. The downside of pwm is it does seem to make some fans take on a high pitched whine though in my experience. Just wanted to keep it relatively simple for this and stick to a simple ac adaptor - from my testing 12v seems to have started them up fine every time so if I go for 15v it should be a pretty safe bet


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## gold3nku5h (Jul 24, 2008)

I was looking for good waterproof fans or ones that can deal with the high humidity, and came across adda fans a while back, so these are pretty reputable for being good with high humidity? do you know if that is true for all ADDA fan models, or have you found any information online about that?


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