Smoke-testing airflow?

[DarkSable]

Okay, so... I didn't know where to put this, since it doesn't really fit anywhere. If there were a fans section under components, I'd put it there, but...

So here's my question. I read somewhere that maxxing out the fans in my case wasn't the best idea, and that I should avoid having a push-pull configuration on my heatsink. I went ahead and put only one fan on my heatsink, because the reasoning made sense, but I put six fans around my Gamma Classic. There are two front intakes, one side intake, two top outputs, and one back output. They're various mixes of 140mm, 120mm performance, and 120mm static pressure quiet, but all are the same brand and function fine.

Now here's the thing. I'm not 100% sure if the airflow is positive or negative pressure, and I'm not sure if my setup is causing any air eddies - I'm kinda afraid there's one right on top of my graphics card. So is there a way to test airflow?

I was thinking I could just light something smokey on fire near the intakes - it would smell horrible, but should show what's going on, right? Or is the air moving too fast to see anything well?

Also, could doing this harm my computer? Is there some other testing method that you'd recommend?

 

[amuffin]

More Intake=Positive
More Outtake=Negative

Sure, I've seen a few people do this, nothing wrong with that. Though I'd prefer dry ice

 

[DarkSable]

Hmm... what's the age limit on buying dry ice? I thought it was 21? [Though dry ice smoke would be less likely to set off smoke alarms. Would it be harder to see through?]

I've got what the terms mean - I just don't know how to find out which I have more of, as I have a lot of fans at different speeds. As far as I can tell, it's roughly even.

 

[smorizio]

talk to a local ac repair guy or shop. see if there leak smoke is electronic safe. you dont want to do anything that hurt the pc over time. the only issue with dry ice..co2 or liquid nitro is water vapor. going from room temp to cold temp your case may sweat. that sweating could short the mb out. that why those high end speeder cover the mb so that water and ice dont short there tests beds out.