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 Post subject: Homemade laptop cooler
PostPosted: Wed Dec 17, 2008 8:51 am 
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Hello,

I recently got an older MacBook, and if I run Folding@Home on it, the CPU fan cranks up -- and it is fairly loud. So, I'm thinking of making a platform with a quiet fan, that is ducted to the exhaust vent on the MacBook; to assist the CPU fan and (hopefully) keep it quieter.

Have you tried this; or know of someone who has? I'm thinking that I could power this with a USB plug -- what voltages are available from a USB? I'm pretty sure there is a 5v, but is there also a 12v?

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PostPosted: Wed Dec 17, 2008 10:09 am 
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Location: Grand Rapids, MI
USB does not have 12v and carries very little current, which is why most higher powered devices need a power brick.

Here is a good pinout diagram.

This guydid something really cool for his MacBook Pro, but it's not ducted or anything.

I wonder if ducting it is even worth it? Just raising it a bit and removing some heat from the bottom of the laptop has got to help the system cool itself, right?

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PostPosted: Wed Dec 17, 2008 11:01 am 
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Hi,

The MacBook that I have is the previous generation (white plastic case) and the exhaust vent is in the gap on the hinge that is created when you open the screen. The intakes are on the back, on either side of the hinge. Because of the location of the exhaust, I think a small duct is required.


It is the fan noise that I want to limit; and not so much the temp of the bottom of the unit. Will the USB 5v current be enough to run a Slipstream 800RPM unit?

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http://neilblanchard.blogspot.com/


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PostPosted: Wed Dec 17, 2008 12:46 pm 
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You don't by chance have the plastic film stuck over the vents like some other unwitting MacBook users do, do you? ;)

I'd be interested in hearing more about your ideas for an exhaust duct. I'm not able to visualize how you would go about doing that. It seems like it would be much easier to create an intake duct to feed air into the machine and keep the exhaust air out.

As for the Slipstream 800, it shouldn't have any problems starting but it would only be ~400rpms and 13CFM. The 1200 might be a better bet at 720rpm/24CFM.

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HTPC: OrigenAE X11|Gigabyte GA-MA785GPMT-UD2H|Phenom II x3 740BE w/AC Freezer 7|150GB Velociraptor|Corsair VX450
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 Post subject:
PostPosted: Wed Dec 17, 2008 1:03 pm 
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I don't know if the software exists for Mac, but all my PC notebooks are undervolted to keep them quiet.

I've played with a bunch of the commercially available notebook coolers and they are all too loud. I've also played with just sticking a free standing undervolted 120mm fans in various places next to the computer and even 5 volted Nexii, etc are too loud, especially for the amount of cooling they provide.

Undervolting has given me temps as cool as when using a laptop cooler, but with the added advantage of less, rather than more noise. Undervolting will generally keep the fan from running at all during normal use, and it will ramp up slower and down faster when the system is being leaned-on.

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