Finding case pressure

[Enablingwolf]

I am curious.....
Would a barometer give reading what my case pressure is like: high side or low side. I read a thread on using AC duct, well right above my pc is huge AC unit, and if I am thinking right..... When the barometer drops it rains.
Now if I get a barometer I can recalculate the pressures so I don't get condensation in my case.. right?
Just another crazy thought going through my mind to drop temps, and maybe use AC ducting.

 

[w00p]

I don't think that condensation has much to do with your case pressure...
Unless there are clouds and low/high pressure area differences sufficient to make windflows, your case pressure doesn't have anything to do with any kind of moisture...

 

[cwzplas]

Dewpoint temperature is when condensation overtakes evaporation, and this is the step in the process of forming water droplets.

http://biomet.ucdavis.edu/frostprotection/fp003.htm

 

[Enablingwolf]

I was thinking of using fans to blow air into the case (to regulate the evaporation rate vs. cold air) and the barometer to use as a calculator to ensure proper air pressure(fans). I live in a humid area and I know the air is saturated enough already, so as I increase the air pressure the evaporation rate should rise? I am just throwing ideas around, I am in first stage researching ducting to an AC unit. So if this sounds corny or off... any input is happily taken.

 

[w00p]

Point taken, they have H²O's that look like ghosts.


Anyway, I'm no fysician, thats why I typed "think" in my former post.

 

[Enablingwolf]

I am reading on how a barometer can fine tune evaporation rate vs. condensation. I will post any relevant links as I find them. (If my theory is correct) I hope I finger this exercise out. I also am not a PhD. in how this stuff works. . I guess, since I started the thread it is up to me to defend the argument(exchange of ideas), of using a barometer.

 

[Enablingwolf]

http://www.du.edu/~jcalvert/weather/atphys.htm
Looks like I am gonna have to break out the graphing calc. and do lots of homework on this one to even begin to understand... , but I think my theory is sorta on track.

 

[Chewsmoka]

I was thinking of using fans to blow air into the case (to regulate the evaporation rate vs. cold air) and the barometer to use as a calculator to ensure proper air pressure(fans). I live in a humid area and I know the air is saturated enough already, so as I increase the air pressure the evaporation rate should rise? I am just throwing ideas around, I am in first stage researching ducting to an AC unit. So if this sounds corny or off... any input is happily taken.

Hiya Enablingwolf - I've had a thread on my A/C ducting solution for a week and a half now, posing the same questions your asking -

http://www.ocforums.com/showthread.php?t=310499

I might be able to help with some questions, check out that thread and let me know.

Peace,
Chewy

 

[Raypundo]

You could use a Diferential Pressure Transmitter (DP Cell for short) to calculate the positive or negative pressure in the case, then reference that agaisnt the barometer.

Getting one might pose a problem though, also the hefty price tag for a low range ("wc)...then there is calibration...

That's just for measurement, then you would have to integrate it into the control system as well.

Anyways I have though of measuring the case pressure with draft gauges, but never to measure and control it hehe. Now it makes me want to put something together at work to do this lol.

Very possible to do this, practical might be another issue.

 

[Enablingwolf]

Ya,
chews,
I read your thread and couple of others, why I got this crazy idea of using a barometer to control fans so there is reducede possiblity of condensation. Right now I am researching a whole new aspect of science to me. Trying to understand how to make a microweather pattern in a case is more than I ever thougth of.
Ray,
Great idea on the electronics. I also thought of Hydrometer(sp?) like they use in aggie applications. Maybe even use a relay switch in conjuntion with fans. When the moisture level reaches a certian point the fans mix warm air into the duct....plus i get benifit of AC in the room
Ahh the possibilities, and thanx for the input all. But right now as I am typing this outside humidity is like 84% so the balance is gonna be real tricky.

 

[Raypundo]

Had some thoughts since then. I was just thinking about pressures, not humidity.

Anyways, I have some equipment where I work that I have humidity control on, and is realatively cheap in terms of the measurement.

Dry Bulb Temp vs. Wet Bulb Temp. Just two temperature sensors.

If you had ducting you could place these in line and calculate Humidty, or find a humidity transmitter (more havc than my line of work).

You would still have to intergrate that into fan control, but finding something to output a voltage should be no problem. That or on/off control, but I'm all about real time tuned analog control

Sometimes I wish I could afford to take my work home with me, but I need to win the lottery first.

 

[Enablingwolf]

Uh oh I am in deep doo-doo.
I made a test model from old case and a fan. I placed a heatsink on a clothing iron. This I figured would create a lovely heart source. Put it all together to test any theories I had and start to understand what routes I should take without risking my beloved "El Cheapo". I had it going right nice, until I cranked the AC to full blast, and didn't think of how much moisture would accumulate when I peeked into the case(opened up the side). Now I got a burnt out iron, and hopefully I can replace it before my wife finds out!!! Darn it!!
The outside humidity is like 91% now. So case pressure does have factor in condenstion I believe. Now to institute some gadgets to control this and make it cheap.
Edit: My methods are far from scientific.

 

[cwzplas]

Just replace the iron from where ya got it, you know nothing, you didn't see nothing, you didn't hear nothing. What iron we don't have a iron. huh, what's it look like?