What is the potential gradient of air?

[frostedflakes]

Am looking to build an ionic cooler, and am trying to find out what the minimum voltage per mm is required to create the corona effect (I understand this is called potential gradient?). Also, breakdown voltage of air is roughly 3000V/mm, right?

 

[DrPizza]

IIRC, the breakdown voltage of air varies significantly depending on such factors as humidity, etc.

 

[frostedflakes]

Really. I figured it would vary based on that, altitude, etc., but assumed the variation was insignificant. Will have to look into it.

But for my purposes breakdown voltage should not be an issue. The project is to build a small ionic cooler for a notebook, due to the small size and close proximity of everything I was looking to keep voltage as low as possible to create the desired effect (air movement). That is why I am interested in the potential gradient.

So ideally I would be right above the potential gradient and far below the breakdown voltage, even in worse case conditions. The corona effect is probably much less efficient at lower voltage, but it is also for a laptop, so I wouldn't need a lot of airflow.

This is all assuming I can even fit the ionic fan in there. I am still considering the feasibility of fitting a high gain (i.e. 5V or 12V to 1000V+?) power supply into this area, how difficult design and building would be, etc. I guess that is another question for Anandtech highly technical.

 

[bobsmith1492]

What's an ionic cooler, anyway? Different potential to move ionized air?

 

[DrPizza]

btw, just out of curiousity, why on earth do you want an ionic cooler? Just a thought here, but the last thing I'd want anywhere near my electronics is something that increases the risk of a static spark zapping my circuits.

 

[frostedflakes]

It's just a project idea I've been rolling around in my head, am still evaluating the practicality and safety of it. The main advantages would be very low noise and high reliability.