Completely Retarded Exhaust Mod Idea? Need Feedback

Will this work?

  • Been there, done that...this won't work.

    Votes: 1 4.2%
  • Been there, done that...this will work.

    Votes: 4 16.7%
  • Completely retarded idea

    Votes: 6 25.0%
  • Sounds interesting

    Votes: 12 50.0%
  • Not sure

    Votes: 1 4.2%

  • Total voters
    24
  • Poll closed .

Notleh

Limp Gawd
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I have found that the exhaust from my 470GTX in SLI are raising the temp in my office considerably. Case cooling is fine and CPU/GPU are all within acceptable limits, but the 90+ degree celsius exhaust from these cards is crazy. I can just crank up the AC, but i do not like this as a long term solution.

I was thinking about running some flexible ductwork from the back of my case (where the cards exhaust) down through the floor of my office into the crawlspace under my house. I would probably connect a fan to the end of the ductwork in the basement to pull the heated air down.

It sounds a bit crazy, but do you think it will work? What are the potential failure points?


Possible issues I can see:
1) My wife may kill me if she notices i cut a hole in the floor! However I can fix this.
2) Condensation may come up from the basement. However, I live in Nevada where there is very little moisture so I do not see this as a big problem.
3) The duct may act like an incubator by trapping the hot exhaust inside the ductwork. I think the exhaust fan in a pull mode will alleviate this problem.

So...thoughts?
 
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I'm thinking that if you are going to go for a crazy duct work system that you try watercooling my friend. Stick a rad down there and enjoy nice low temps.
 

jeremyshaw

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Airflow ducts are more common in server envoirments. However, why not just have the heat go out a window, and insulate the area around the window?
 

Notleh

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I'm thinking that if you are going to go for a crazy duct work system that you try watercooling my friend. Stick a rad down there and enjoy nice low temps.

The 470's run at 91 degrees celsius. Would WC really help that much? And at what price range am I looking? I was under the impression (with only minimal research) that I would have to spend at least $300 to get started on a decent WC.
 

Notleh

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Airflow ducts are more common in server envoirments. However, why not just have the heat go out a window, and insulate the area around the window?

I thought about this, but it may look too jury-rigged. I can get a nice clean look by going straight down. But it is pretty much the same principle.
 

jeremyshaw

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The 470's run at 91 degrees celsius. Would WC really help that much? And at what price range am I looking? I was under the impression (with only minimal research) that I would have to spend at least $300 to get started on a decent WC.

I spent about 170usd to WC my HD5770 crossfire setup, about 3 months ago. About 220usd, if you want to include the 4 GT AP15 I bought for my 240rad.

Will it reduce the HEAT? No, that GTX470 will output the same amount of heat (well, a little less, since there is less resistance due to heat, and consequentially, less heat due to resistance - all electrical).

Will it reduce the exhaust tempuratures? Hell, yes.

Will it make your room cooler? No, unless if you setup the rad outside of your room. Heat output remains about the same, just spread out over a greater area, and dissapated more efficiently.
 

vsboxerboy

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I would imagine that the heat would find its way back in, either through cracks in the floor or by heating the floor itself slightly. I'm sure you will notice a temp decrease, but for how much it's going to be a PITA to do, I would imagine that it will be very much not worth it. I really think that dumping the heat out the window is the best option for the money but if you have the money, going for a wc setup with an outdoor rad.

Hell, it would be easier to just put the damn PC in the crawl space and use some longer cables lol
 

NKDietrich

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The 470's run at 91 degrees celsius. Would WC really help that much? And at what price range am I looking? I was under the impression (with only minimal research) that I would have to spend at least $300 to get started on a decent WC.

Probably a bit more than $300 for a good dual 470 loop. Plus that guy has forgotten about the laws of physics. Everything is still putting out about the same amount of heat, it's just being moved around more efficiently. So you'd still need a duct to take the heat out of the room, and you'd be back to square one.

I'd do the window idea honestly :p Heat in the basement is going to end up back in your house somewhere.
 

bluemoon4me

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I was thinking about running some flexible ductwork from the back of my case (where the cards exhaust) down through the floor of my office into the crawlspace under my house. I would probably connect a fan to the end of the ductwork in the basement to pull the heated air down.

How much money / time do you think this would cost you? I'd be interested in the results. I'm not a fan of WC, I think it's too much upkeep. I think as long as the duct isn't terribly long, and the fan at the end is big enough, you might get good results. But I also think the amount of hot air you want to pull out would have to equal the amount of cool air you want to take in. Do you have a window in your basement or is it completely underground? Also, are there any AC vents nearby?
 

Ehren8879

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exhaust hot air out the window (outside) with some ducting during the summer.

use same ducting to pull in cold air during late fall & winter months. Be clever about possible moisture though
 

Sakom

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I like the window idea as well. I live in Vegas myself and we have more dust to worry about than moisture issues.
 

Hornet

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Interesting idea, but as vsboxerboy pointed out, the air in the crawl space would need to go somewhere and it'll probably be pushed through the cracks on the floor. Unless there's airflow somewhere that allows air to move in and out
 

rive22

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This works great just use a good duct that will retain the heat, similar to a dryer duct.

I did something like this using an 80mm plastic ducting tube bought from a car parts store and while it works good for a cold air intake, using it as exhaust is no good because the heat just bleeds right through.

A good dryer duct will do the trick, if need be wrap a little insulation around it, you can then wrap black or white duct tape around it and make it look nice and neat. or whatever else you have in mind other than thin plastic.

Also shoot for 120mm if you can. 80mm at the least. Anything less and it's not going to work well. Put one fan on each end of the tube is all you need if you create a tight seal with custom mounts. Then use pwm or a fan controller.

I use this method for my whole computer case the thing is sound damped & sealed except my exhaust goes out the window.
 
Last edited:
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I have done something similar during the winter, as my room is on an upper floor, and it gets quite hot up here during the winter even with HVAC vents closed off, doors shut, and a window opened. Except, i had it setup with a fan on either end, one pushing it through the vent, through about 6ft of flexible metal venting, to a window. I really hate the heat, indoors anyhow.
 

rive22

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I love it in the winter I turn the fans around and use the outside as an intake and I open a port to exhaust in the room. I then leave my window opened and the heat from the case keeps the room nice and cozy while still having cool fresh air from outside circulating.

It's awesome
 

drescherjm

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I spent about 170usd to WC my HD5770 crossfire setup, about 3 months ago. About 220usd, if you want to include the 4 GT AP15 I bought for my 240rad.

Will it reduce the HEAT? No, that GTX470 will output the same amount of heat (well, a little less, since there is less resistance due to heat, and consequentially, less heat due to resistance - all electrical).

Will it reduce the exhaust tempuratures? Hell, yes.

Will it make your room cooler? No, unless if you setup the rad outside of your room. Heat output remains about the same, just spread out over a greater area, and dissapated more efficiently.

Wouldn't this only add heat to the situation? I mean the pump and radiator fans use more power than the fans they replace.
 

hiodie

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Can you run the exhaust up into the attic? Should help keep the heat from getting back into the house, and should be a little better sealed off from critters. Harder to hide the nice aluminum ducting going up the wall though...
 

Notleh

Limp Gawd
Joined
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Great comments. I am seriously considering doing this project. I will draft up something today. I am thinking maybe $40.

-I think the window issue is a good idea, but my home office is on the first floor, so this causes security issues.

-I could vent it up to the attic, but that is a long way to send the heat since my house is 2 stories.

-Animals would not be an issue. The Basement is actually a 4 foot crawlspace and it is pretty well sealed. Furthermore, I would only have the venting go a couple inches through the main floor, so it would still be about 3 feet off the ground in the crawlspace. I will also put in a backdraft protector.

-The crawlspace is basically a cement footing around the perimeter of the house, with open air vents every 15 feet or so. I do not think the basement will heat up too much more in the summer (no more than my office is!) and the heat in the winter will be a bonus (or i can remove the vent).



My biggest issue is how I am going to modify the vent ductwork to interface with the back of the case, where the 470's exhaust.
 

ghost6303

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Wouldn't this only add heat to the situation? I mean the pump and radiator fans use more power than the fans they replace.

fans/pumps put out a trivial amount of heat. removing or adding a fan would have as close to zero difference as you can get.

if you have a video card that pumps out 200 watts of heat, it doesnt matter if you blow that heat around with a fan in the case, or contain it in water and pump it elsewhere to radiate, its still the same 200 watts of heat.


OP- you are talking about a relatively small amount of airflow; you should have no problems whatsoever doing this. even if that space were hermetically sealed i doubt you will see any noticeable increase in crawlspace temps. the cement down there would be able to absorb many many times the amount of heat that the incoming air could supply and dissipate it into the earth.
 

drescherjm

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I was figuring that a pump and extra fans on the radiator would add 30W+ which may be insignificant compared to a 200W GPU but that is a lot more than just a CPU + GPU fan.

if you have a video card that pumps out 200 watts of heat, it doesnt matter if you blow that heat around with a fan in the case, or contain it in water and pump it elsewhere to radiate, its still the same 200 watts of heat.

I certainly agree with that.
 

Notleh

Limp Gawd
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Just to put some numbers to it:

Running certain games, the 470GTX's are running at 91C/196F at the rate of 94 CFM (47cfm per at 100% fan rate).

I think step 1 is measuring my baseline temps, then step 2 is to do a temporary test of running it out a window. If that seems to have a noticeable impact then I will work on a more permanent solution.
 

AdvanSuper

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I'm thinking that if you are going to go for a crazy duct work system that you try watercooling my friend. Stick a rad down there and enjoy nice low temps.

There is still going to be heat in the room. Once that heat gets to his rad/s and is blown out his heat problem is still there. It might not be as bad, but it would still be an issue. He needs a way to get the heat out of the room so it doesn't turn it into an oven.
 

vengence

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Just to put some numbers to it:

Running certain games, the 470GTX's are running at 91C/196F at the rate of 94 CFM (47cfm per at 100% fan rate).

I think step 1 is measuring my baseline temps, then step 2 is to do a temporary test of running it out a window. If that seems to have a noticeable impact then I will work on a more permanent solution.

Temporary tests out the window sounds like the best solution for now.

Also think about changing your setup. Is this PC setup next to a wall or in a corner or something? If it is, move it back a bit so you aren't trapping all the heat at your desk. Rooms need good air flow paths just like cases do.

Outside of that, if you are planning to exhaust your exhaust, you might want to pull some air in from outside to go into the case, otherwise you're just sending the air you worked so hard to AC into the case and then outside.
 
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