I did this recently because i had the parts lying around. Otherwise i dont really think its cost effective. Kinda fun and unique though. Sorta lame diagram i made with MSpaint while on my lunch break.

forgive me, but I can't tell from your pic what is the mod... what I see is the standard way to vent a box.....

The image size got messed up when i uploaded.

What it basically does is measure the static pressure inside the case ( intake vs exhaust ) to let you know how much air you are moving. The gauge is mounted in the top of the case with a diode mounted inside.

For example i found that with the increased static pressure of not having an additional intake fan that my case moves 10% more air than with the extra intake. 1 fan less, less noise, slightly less power, less cable clutter and it moves more air.

Its vanity mostly. Completely worthless and un-needed by 99.9% of users.

If it wasnt clear enough the red thing in the top of the case is the gauge you see at the bottom right corner of the picture with the diode below it.

How can you tell how much air you are moving without any sort of measurement of the volume of air entering or exiting the case?

If you get the digital gauge it allows you to input the cubic feet of air space and it calcs that against the static pressure pull on the diode and gives you a +/- 5% cfm number for the entire case. .

The way i did it there really is no way to know EXACTLY how much air you are moving. Like if you taped off all the intake holes and just had exhaust the pressure would go really high where as the pressure would be zero with the computer off.

I have an analog gauge and a digital gauge. I hot swap them to see roughly how many cfm im getting when the analog gauge is on. A +2.5 static pressure on the analog gauge is roughly equal to 275 cfm on the digital one.

I told you it was more effort than its worth. Im a very bored individual.

Nothing wrong with having an active mind

Got it....my bad...didn't realize that you installed a gauge....
pretty cool idea. That used with a quality temp probe could net some good info!

Interesting. So basically have more exhaust fans than intake fans?

it depends... EVERYONES case is different...

what the mod is is to install a guage to measure... use it for testing purposes....

some cases like more intake, so like more output, just try different things and see what results you get

In my case for example, I have two 80mm fans as intakes and two 120mm fans + the 80mm from the PSU + the 2900XT fan as the exausts, and it's been working great ever since. It'd be interesting to see how it compares though, be sure to post results

is there a second gauge outside the case to compare the pressure difference?

Curiosity here....i thought you wanted positive pressure in a case...because positive pressure requires more energy to increase heat? Where negative pressure (vacuum) would require less energy to heat something up? So, if this is the case...then why have more exhaust fans than intake fans?

That makes perfect sense. I didnt really have functionality in mind when i did it, it mostly just came after the fact when i realized that it would work

I was in the middle of a rebuild at the time so i didnt test for temps and only messed around with the total case CFM circulation with various fan setups. I still have to get more weather stripping to seal the case door and front panel so the static pressure is more accurate with less variation. After that i will spend some time swapping fans, taking notes and then throw it on a spreadsheet with CFM, temp, pressure, fan placement and number of fans compared.

Hope to get some good pics by then as well.

As for the pressure outside the case, the digital gauge has room for up to 4 diodes. In the event you wanted to read and compare inside/outside pressure you would just plug it in and program it onto the lcd display.

My ultimate goal is to do the digital gauge mod with both diodes on my Armor case. The analog mod i have done is on an older Lian Li. Just have to mod the drive bay a little since the digital one doesnt exactly fit.