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XPS 8920, added 120mm front fan (with pictures)
Just happened to have these
Add double sided tape to low spots
Cut 3/8" thick weatherstriping pieces for corners and wrap with 1/4" x 1 weatherstriping
Add a little glue to 1/4" sides. It touches on 3 sides, not going anywhere.
Tape anywhere air can get in other than outside.
Pwm signals pulse , not controlled by voltage and are more precise for synching.
Those rectangular vents are the only place (outside) air can get in.
I tapped into the top fan lead with the Arctic fan pigtail (cpu fan spins too fast)
I found one more breezy area and used some more weatherstripping to fit
Anonymous
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274.2K Posts
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March 4th, 2019 13:00
That is the only place fresh air can get in . . . but your fan is sucking case air from that bottom port, unless you have blocked that off, or taped over the vents below your HDD drives.
546insp
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July 25th, 2018 01:00
Update; This new front fan dropped the air temperature 9* F on the average at the top fan and eliminated the fan racing when stressed, also it is completely quiet.
Anonymous
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December 15th, 2018 21:00
Great pictures - very helpful. Now I see what you mean by sealing off extraneous air sources. I am going to try to put two fans in the front; top and bottom. I don't really need to, I don't have a heat problem, I don't even game. I'm just having fun and hopefully learning a little from this community.
Anonymous
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March 3rd, 2019 18:00
Isn't the hot case air that is pulled across your two lower HDD baskets and out the bottom vents sucked through this lower front base port and circulated back into the case by your fan?
546insp
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March 3rd, 2019 20:00
???? Can you rephrase that?
Anonymous
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March 3rd, 2019 21:00
sorry, sometimes it takes a while for pictures to be approved - arrows are supposed to represent air flow.
546insp
732 Posts
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March 4th, 2019 09:00
The only place the air can get in is at the 1/4" wide gap at the bottom and sides in extreme front, all else is blocked off. The air goes straight back and up (much better than a top mounted fan).
546insp
732 Posts
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March 4th, 2019 14:00
Anonymous
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March 4th, 2019 16:00
Thanks to you!
The only reason I am even looking at air flow is because of your advice in this discussion.
546insp
732 Posts
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March 4th, 2019 18:00
At least this method now draws 100% outside air with a straight shot back towards the vital areas. Not bad for the first mod I have ever done on any computer other than replacing parts, plus it cured my loud fan problem and now, thanks to you, it will be even better.
dandelionclock
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April 7th, 2019 19:00
Could you share some temperature differences, especially after blocking off the "basement backflow"?
546insp
732 Posts
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April 8th, 2019 07:00
I think it's even cooler now, the most it ever reaches with video, virus scan, and another program running at the same time is 85* F at the top with a thermometer laid on the vent. This is the best mod I have ever made on any PC, it completely knocked out my fan noise problem any it's funny how everyone downplays it as if only their $300 super duper water system with radiators will work.....lol. I think I have a total expense of about $12. (Whatever that Arctic fan cost), plus it was kinda' fun doing it.
546insp
732 Posts
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May 16th, 2019 13:00
simmil
1 Message
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June 3rd, 2020 05:00
Sorry, old thread revival and all, but I'm about to try the same mod on my XPS 8920 and had a question on the wiring for the 4 pin fan connectors.
Looking at your pictures, did you wire directly into the top fan plug, or did you use a splitter?
Reason I ask is that I've read a lot on here about Dell switching the wiring order compared to standard for the fan headers, that it can be difficult to tell sometimes and some Dell's use standard anyway. As far as I can tell the case fan header socket on the motherboard is 4 pin, do you happen to know if it is standard wiring on these?
I have an Arctic P12 PWM PST fan I was going to use, it has the splitter built in to the cable, so I planned to plug this into the motherboard, then the top case fan into the splitter. Obviously don't want to do this if there's a chance the fan or motherboard goes pop!!
Thanks for any help you can offer.
GKDesigns
258 Posts
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June 3rd, 2020 15:00
My XPS 8930 i9-9900 MB case fan header is standard wiring:
pin1, black, Ground (-)
pin2, red, 12VDC (+)
pin3, white, RPM signal from fan
pin4, blue, PWM signal from MB
A 3-pin unregulated fan omits pin4 and will still work on a 4-pin header.
A 2-way splitter routes pin3 from only one of the fans, because the MB logic only regulates for one RPM signal. It is assumed that the other fan is identical and will follow at the same controlled speed.
A concern is that the two fans not draw too little or too much current, so aim for the current of the OEM fan. Too little current and the BIOS might error thinking the fan has failed; too much current might damage the MB. I would be most concerned about too little current... this problem can present when you replace one inefficient OEM fan with one very efficient after-market fan... so it's a good idea to replace the one OEM fan with two very efficient fans to get their combined current up to keep the MB fan logic happy.
My fan upgrade: https://www.dell.com/community/XPS-Desktops/XPS-8930-how-is-the-cooling-in-the-i9-9900/m-p/7508730/highlight/true#M46666
GK