Controlling HTPC Case Fans Automatically?

[foogama]

I just finished my first HTPC build for WMC and my only gripe is the case fans are running full blast, non stop, and for the life of me, I cannot come up with a solution. Temperature is not an issue, it's simply a fan control issue. Before I dive in detail on my trouble shooting, here is my build. (Sorry for the URL strings. The forum only allows me to post three URLs per post? Is this a serious policy? Is someone unaware that the internet contains links?)

Case: url=http://www.amazon.com/gp/product/B004GGUAUE Silverstone ML03B
PSU: url=http://www.amazon.com/gp/product/B002UOR17Y Antec EarthWatts EA-380D
CPU: url=http://www.amazon.com/gp/product/B0093H8H8I Intel i3-3225 w/ on-board Intel HD 4000 Graphics and stock fan/cooler
RAM: url=http://www.amazon.com/gp/product/B0037TO5C0 Kingston Hyperx 1600 MHz 8GG (2 x 4GB)
MoBo: url=http://www.amazon.com/gp/product/B007OCJWTM ASRock H77M LGA 1155
SSD: url=http://www.amazon.com/gp/product/B009NHAF06 Samsung 840 (120 GB) for Windows 7 Ultimate
HDD: TWO url=http://www.amazon.com/gp/product/B008YAHW6IWD Green 2TB 64MB Cache in RAID 0 for plenty of Movies, DVRs, etc. (also a pseudo NAS through SAMBA)
Tuner: url=http://www.amazon.com/gp/product/B003B4VLJQ Ceton InfiniTV 4 Quad tuner through Comcast
NIC: url=http://www.amazon.com/gp/product/B007GMPZ0A TP-Link Dual Band 802.11a/b/g
Fans: Three url=http://www.newegg.com/Product/Product.a ... 6835150007 MASSCOOL 80mm fans pushing air into the non-PSU side of the case

The ASRock H77M MoBo only has two Chassis Fan headers, one three-pin (w/ controller) and one two-pin (w/out controller). The third fan I just have hooked directly to the PSU via 2-pin molex connection. I realize through that setup, the system should only automatically control one of those three fans, but even that does not occur. All three fans are on full-blast, all the time.

In BIOS, there are settings on how fan headers are controlled, but changing the setting from "Automatic" to "Full On" or even "Manual" on Levels 1 through 9 don't even change the fan speed. I found anotherpost from someone that gave a screen shot of the H77M bios with the fan controller options. He came to the same conclusion: the MoBo doesn't support fan control.

I'm perfectly content buying a PCI fan controller, but every single one that is mentioned online is either discontinued or not in stock. Does anyone know of a PCI fan controller? Alternatively, I'm open to hearing any other solutions that allow three 80mm case fans to automatically vary speed, based on the temperature of the system/CPU.

[barnabas1969]

Those fans move more air than you need, and therefore are much louder than you want. Before you buy a fan controller, I'd recommend these fans:
http://www.newegg.com/Product/Product.a ... 6811999199

I have three of them in my HTPC. Their max speed is 1500RPM. My motherboard controls two of them, and they usually run around 1200RPM. I soldered a resistor in series with the third fan. I experimented with different resistor values until I found one that runs the third fan at a continuous 1200RPM. My PC is whisper quiet. I can't hear it unless I'm closer than about 3 feet from the HTPC.

After you install three of the fans I recommended, then if you still want a fan controller, try one of the ones listed below:

http://www.newegg.com/Product/Product.a ... 6811996023
http://www.newegg.com/Product/Product.a ... 6835118217

[foogama]

Those fans move more air than you need, and therefore are much louder than you want. First, I'd recommend these fans:
http://www.newegg.com/Product/Product.a ... 6811999199

I have three of them in my HTPC. Their max speed is 1500RPM. My motherboard controls two of them, and they usually run around 1200RPM. I soldered a resistor in series with the third fan. I experimented with different resistor values until I found one that runs the third fan at a continuous 1200RPM. My PC is whisper quiet. I can't hear it unless I'm closer than about 3 feet from the HTPC.

Getting fans with a lower max-rpm is an option, I suppose, but in theory, the fans I already have should be relatively easy to control the speed of with the right hardware. I also have 0 soldering experience but have a friend that could help me out. But if my MoBo can't variably control ANY fans, then I don't know how much that would help me long-term.

[foxwood]

Have you tried software like SpeedFan that can report on temperatures and fan speeds, and can control the fans if the motherboard supports it ? I think there are forums on the Speedfan site, if you register and log in:

http://www.almico.com/speedfan.php

[barnabas1969]

Sorry. I guess I edited my post too late, and you posted after me. Go back and read my edited post #2 above. Give my advice a try. They aren't expensive, and you won't be disappointed.

[foogama]

Have you tried software like SpeedFan that can report on temperatures and fan speeds, and can control the fans if the motherboard supports it ? I think there are forums on the Speedfan site, if you register and log in:

http://www.almico.com/speedfan.php

Excellent idea! That would definitely help troubleshoot the MoBo's functionality as well.

Sorry. I guess I edited my post too late, and you posted after me. Go back and read my edited post #2 above. Give my advice a try. They aren't expensive, and you won't be disappointed.

Do you think four 1,500 rpm fans can keep two 7,200rpm WB Green HDDs in RAID0 plus a 400W PSU cool? Those three items are located on the opposite end of the case from where the fans would be.

[barnabas1969]

Do you think four 1,500 rpm fans can keep two 7,200rpm WB Green HDDs in RAID0 plus a 400W PSU cool? Those three items are located on the opposite end of the case from where the fans would be.

Your PSU has it's own fan. You don't need to worry about that. A little bit of air flow goes a long way. How cool it keeps things has more to do with the path the cool air takes as it goes through your case, than it has to do with the velocity of the air. I have two 7200RPM drives in my case, plus an SSD, a 650W PSU, two tuner cards, and a couple of I/O expansion cards, a fanless nVidia GT-430, and a 95 watt CPU (yours is only 55 watts). My case has 3 of those 1500RPM fans in it, and it keeps everything at a safe temperature. As I said before, mine is completely silent from a distance of more than 3 feet.

[barnabas1969]

I've looked at your case before. In fact, I know someone who has that same case. If you put a fan in all four positions on the side, all blowing outward (exhaust), then you'll be fine. Do not mount some blowing in, and others blowing out. If you do this, then the hot air will simply be sucked right back into the case. Also, if you don't use all four fans, then cover the unused vents with cardboard or something. You need to avoid "short circuiting" the air. You don't want an open vent right next to a fan. If you do this, then the fan will blow warm air out, and suck it right back into the vent next to the fan.

The PSU you chose draws air from inside the case too. That should be OK, but the case was designed for a PSU with a top/bottom air intake so that the PSU's air vent could be positioned over the vent in the bottom of the case. The only problem you might run into is if the case fans are too powerful (creating a negative pressure inside the case), then the PSU may be starved for air.

I'd be willing to bet that you could get away with 2-3 fans on the side of that case, blowing out (exhaust), and cover the remaining 1-2 fan mounting positions with cardboard.

[barnabas1969]

Oh, and one more thing. Don't put the PC in an enclosure without sufficient ventilation. If you put it in an enclosed shelf, make sure there is at least 2 inches of space on the top above the CPU intake vent, and at least 2 inches of space on the side where the exhaust fans are. Also, leave the back of the cabinet open. Cut a hole in the back of the cabinet if you need to, and make sure the hole extends at least 2 inches above the top of the PC to allow the warm air to rise up out of the cabinet. If the cabinet has a door on the front, then you need to make sure that there is somewhere for cool air to come in. The hole for cool air intake needs to be lower than the warm air exhaust hole.

I hope that makes sense. I don't know if you have your PC in a cabinet. If it is, then you need to provide a way for cool air to enter the cabinet, and warm air to escape.

[foogama]

Don't put the PC in an enclosure without sufficient ventilation

This will be in a 4-walled enclosure with a completely open back, but will have more than 2 inches on each side and the top as well.

If you put a fan in all four positions on the side, all blowing outward (exhaust), then you'll be fine.

I believe the case has a "positive pressure" design, meaning air was meant to be sucked in, and then forced out the vent in the top. Is that correct? I'm not at all opposed to trying what you've suggested (it sounds perfectly feasible and practical to me), I just want to be sure I'm not somehow counteracting the design of the case, thus rendering it ineffective, overall.

I'd be willing to bet that you could get away with 2-3 fans on the side of that case, blowing out (exhaust), and cover the remaining 1-2 fan mounting positions with cardboard.

I ordered four of the 1,500rpm fans you suggested. I will mount three of them to suck air out of the case and cover the fourth hole with cardboard. If it's quiet enough and keeps things cool enough, I won't even bother trying to troubleshoot the MoBo headers or fan controlling options.

Great points all around, thanks very much for the advice!

[barnabas1969]

Don't put the PC in an enclosure without sufficient ventilation

This will be in a 4-walled enclosure with a completely open back, but will have more than 2 inches on each side and the top as well.

That should work OK.

If you put a fan in all four positions on the side, all blowing outward (exhaust), then you'll be fine.

I believe the case has a "positive pressure" design, meaning air was meant to be sucked in, and then forced out the vent in the top. Is that correct? I'm not at all opposed to trying what you've suggested (it sounds perfectly feasible and practical to me), I just want to be sure I'm not somehow counteracting the design of the case, thus rendering it ineffective, overall.

It makes more sense to me for the fans to be exhausting warm air. This will draw air into the top vent, supplying the CPU fan with fresh air. However, it could work either way. It wouldn't be too difficult try it both ways. You could install them as intake fans, and then run the PC under a load, and log the temps with Speedfan. Then, swap the fans around the other way and run the test again. Make sure to log both tests (to two different files) so you can compare the two configurations. Then, just use whichever one works best. If you do this test, I recommend running it while the PC is actually in the enclosure with the door closed (if you'll normally run it with the door closed).

I'd be willing to bet that you could get away with 2-3 fans on the side of that case, blowing out (exhaust), and cover the remaining 1-2 fan mounting positions with cardboard.

I ordered four of the 1,500rpm fans you suggested. I will mount three of them to suck air out of the case and cover the fourth hole with cardboard. If it's quiet enough and keeps things cool enough, I won't even bother trying to troubleshoot the MoBo headers or fan controlling options.

Great points all around, thanks very much for the advice!

Well, like I said, my three fans run at about 1200RPM and they're very quiet. If you're happy with them running at 1500RPM, then you won't have to do anything else. Otherwise, you could install some inexpensive fan controllers or have your friend solder some resistors in series with the fans. One thing to be aware of is that one of the three wires on the fans is the speed sensor wire. So you don't want to put a resistor on that wire. Putting a resistor in series with either of the other two wires is fine. I don't remember which wire is which, but I'm sure that info can be found online. I I figured it out by disconnecting one fan wire at a time until the fan ran, but no speed was registered in BIOS. Then, I put a resistor in series with one of the other two wires, and reconnected the speed sense wire.

There are other reasons why my PC is so quiet. Case fans are only part of the equation. I have a very quiet CPU cooler. I don't know what you have for your CPU. If your CPU fan is loud, it won't matter if you have quiet case fans. My PSU is also completely inaudible until it is loaded more than 90% of full load (as tested by Silent PC Review).

I did a lot of research to make my PC as quiet as it is. I even modified my HDD mounting cages and installed rubber dampers to prevent the HDD sounds (which were pretty quiet to begin with) from being transmitted to the case.

You can see my system specs by clicking the link in my signature below. Keep in mind that my CPU cooler will not fit in your case, because it is too tall. All I can tell you is that the "Scythe SCBSK-2100 120mm Sleeve BIG Shuriken 2" definitely fits in your case. I know someone with that cooler in that case.

[RobsterUK]

If you are looking for a system to control all of your cooling fans linked directly to your CPU fan check this out.
http://www.arctic.ac/en/p/cooling/acces ... cable.html

I am using the PWM case fan as my mobo has PWM connectivity. It does what it should, spins up when hot, then spins down again when it's cooled.
But this PST cable that links all the fans in the system together looks like an ideal solution for mobos without case fan control built in.