Add-on Panel Brings Automated Vents Flaps To A PC

[SXRguyinMA] built a replacement top bezel for his computer case. He wanted to add vents that would automatically open or close based on the cooling needs of the computer. With some careful measurements he modeled the parts in Sketchup and sent out for them to be cut from styrene with a water jet cutter. The parts came back looking great and the assembly of the shutters went swimmingly. The bezel also includes a lighted screen for temperature information, as well as the front USB ports, headphone and mic jacks, etc. Hidden underneath is an Arduino board and servo motor. The Arduino polls the temperature and drives the servo to adjust the fins accordingly. There’s even a supercap in the circuit that will close the vents when the PC powers down or when power is unexpectedly lost. See it in action after the break.


37 thoughts on “Add-on Panel Brings Automated Vents Flaps To A PC

  1. I’d set up a delay in closing the vents after shutdown, along with running the heatsink fan a few extra minutes, to cool down the CPU and other components. The heat doesn’t magically go away when the computer shuts down, but the fans and everything are turned off anyway.

  2. Nice build, but using an arduino to do this seems overkill to me, there are temperature sensors out there that can turn on fans or even a fan controller from the motherboard would suffice.

  3. Very clean build. Wish I had the patience to tackle this.

    @delirium: I think the PWM output from the motherboard wouldn’t drive a servo directly. The frequency and duty cycle required are quite different. You’d need some circuitry between them, a microcontroller make it easy and cheap, and an Arduino has the advantage that the firmware can be updated in-situ.

  4. The cost of the atmega chip and the few extra components are heavily outweighed by the simplicity of coding for an arduino :)

    Burnbootloader onto atmega chip, connect the crystals and so on, add a temperature probe (or anything similar) and a servo+rails – add the code and it’s pretty much done.

    This is why i love the arduino, it makes it much less likely for headaches to happen :D

  5. I would time the closing of the fins out a little opposite-like so that the heat from the cooling system isn’t trapped inside after shutting down.

    Either way, that is an impressive-as-hell hack.


  6. The action on the open/closing is great, this turned out really well, must have taken a lot of patience and measuring twice.
    You could probably use a micro to do a pwm compare on the motherboard fan controller,then adjust the servo accordingly.

  7. Thanks for all the feedback guys!

    @Craig Burden: I like the idea of having it close slower, I may try to work that into my coding!

    @peter larson: The Alienware case is where I got the idea for this. I was originally going to do it as a mod to my Thermaltake Armor case, but I won this NZXT Tempest EVO in a contest and it already had 2 140mm exhaust fans in the top, so it worked perfectly!

  8. There’s no benefit from “aftercooling” things. It’s not like a car engine where you might get hot spots after a hard drive, that might then damage something as the heat starts to spread.

    The chips and the heatsinks have so little thermal mass that they start cooling immediately after the power is cut.

  9. @24601 The fans in a pc turn off when the pc turns off because the components will not get hotter then there already are. Components only get hot when a electric voltage is run through them.

    “I’d set up a delay in closing the vents after shutdown, along with running the heatsink fan a few extra minutes, to cool down the CPU and other components. The heat doesn’t magically go away when the computer shuts down, but the fans and everything are turned off anyway.

    Posted at 11:20 am on Oct 10th, 2010 by 24601”

  10. @Eikka

    True, but it would give the system a .05% greater reliability to remove the heat immediately. Not really, I don’t have numbers or know if that would help or not, but it would be pretty sweet to see the system being cooled for an extra thirty seconds then closing up.

  11. euphorix: “Components only get hot when a electric voltage is run through them.”
    That would be “AN electric” and you don’t run voltage through anything. You can do that with electric current, but you just supply the voltage.
    Get your shit straight.

  12. Just using a atmega is not that hard. I dont use external crystals unless the timing is really critical (and if the timing is that critical you the ardino have to much overhead).

    I dont use any bootloaders and use plain c.
    A simple make file so it’s just “make && make install”.

  13. Have you left the 2 fans underneath the vents in the case? If so you have probably lessened their cooling effect.
    But I’m inclined to say who cares! It makes the already awesome NZXT Tempest Evo even more AWESOME!!

    Yes, I own one too :)

  14. It’s likely the point of the vents is to have a quiet method of shunting hot air from the case. He likely has some passive vents at the bottom of the case to let cool air in. Having two fans probably WOULD make it cool better, but if you were going to do that you wouldn’t go to all the trouble of having adjustable vents and just have two static vent fans, right?

  15. To those saying there’s never any point closing the vents: Wouldn’t that possibly help lower thermal cycling when the computer is briefly powered down? I would think that keeping the machine at a constant temperature would be better for longevity than always keeping it as cold as possible (though ideally it would be constantly cold).

  16. The purpose of closing the vents is that I shut off my computer every night, and its very dusty in my house. Closing them makes it so the dust floating around doesn’t float it’s way down into my case :)

    And I couldn’t find a way to use the +5v standby to power the Arduino. I use the 5v as the sense pin to tell the Arduino if the computer is on or off, and adjusting the vents accordingly (open or closed). This same +5v triggers a relay which lets +12v through to a +5v red to charge the caps. The reason for the relay is the system would backfeed through itself and it would not take 5v away from the Arduino’s sense pin, and the vents would stay open until the caps drained.

    I plan in the future to put the ATmega320 on it’s own custom board with the backup power circuitry all integrated into the board, rather than on 2 boards.

    I had thought about the idea of leaving the vents open for a few mins after the computer is off to let the heat naturally migrate out, but like others have stated, once the components are powered down they’re not generating more heat so it’s not really needed :)

    And yes, I did retain the 2 140mm exhaust fans under the vents that came with the Tempest EVO. The fans are controlled via the NZXT Sentry 2, along with every other fan in the case (8 total).

    Also, thanks to HAD I went from 1.7GB usage on Photobucket to 13.3 :D So for those of you that check out the worklog the pics won’t be visible! I’m working on getting the Pro account, so bear with me :D

  17. @pyrhho:

    The vents are tied to the temp of the CPU actually. On a cooler morning the vents are hardly open, and as the computer warms up they open more. I’ve got the coding set that way :D

    The video just shows them popping so far open because I had just had the computer on and shut it down to take the vid.

    I’m working on a way to make them close slower on shutdown though just for a neater effect.

  18. Pretty nice and clever, you avoid the noise when webbrowsing but have cooling when playing games, I’m amazed that not all cases above a certain pricepoint have this.
    But now that he thought it up maybe they will :)
    BTW, I know they made some cases with moving parts, but not plain and simple and functional like this that I recall, those cases were more doing it to get attention.

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