I have rebuilt my HTPC (for the third time) in a Habey EMC-800B case. I went with the 800 over the 600 to get a little more height, as I removed the steel plate that's use for optical drive mounting. But it's still not that tall...

What I've got is an i3-2100 in there right now with the stock Intel heatsink/fan. (Side note: FYI, the stock fan is actually too tall for use with the optical drive bracket, although my understanding is that the i3-2100T comes with a shorter HSF.) My original two revisions of this HTPC used an i5-2500K, but so far, the i3-2100 has had no performance issues... but I keep thinking maybe I should just use it anyway.

Anyway: as best I can measure, it looks like there's about 65--66mm of clearance from the motherboard to the top of the chassis. So here's my question: I was originally thinking of using the Scythe Big Shuriken, which is 58mm tall. That gives me about 7mm of "breathing room" between the fan and the top of the case. Is that enough? Or will the airflow impedance offset the utility of a bigger/better heatsink?

Another option would be to go with the Scythe Kozuti. At 40mm tall, this is even shorter than the stock Intel HSF, and would have plenty of breathing room. But---I'm afraid it would leave me insufficient headroom if I decided to use the i5-2500k.

Third option is to use the Kozuti with a slim (12mm thick) 92mm fan. This would make the Kozuti 52mm tall, yielding about 13mm of "breathing room".

And of course there could be other options that I haven't conceived.

What do you folks think?

Thanks!
Matt

There's the Coolermaster Gemin II M4, which is basically a Big Shuriken with heatpipe direct touch.
Noctua presented a cooler at the CES with a minimum height of 66mm, but it hasn't come out yet.
The Akasa AK-CC9101BP01 (catchy name) is a 2U with a different airflow, the fan is probably not quiet, but you could use a Zalman PWM fan mate.
The Prolimatech Samuel 17 is very short at 45mm without a fan. construction and mounting are very good, but the price is steep and performance is only slightly better than Big Shuriken's.
The Zerotherm ZT-570D might be worth mentioning, it's an all copper cooler, but too tall with the included fan.
The Zalman CNPS8900 Quiet is a new take on the zalman's round cooler theme, this time with heatpipe direct touch. It looks great, but the min RPM of the included fan is 1000 and it's hard to replace.

Thanks for those added suggestions.

I guess the fundamental question is, how much room is needed between the chassis and the fan to ensure adequate "breathing room" for the fan?

I vaguely recall reading once that the minimum height is either the height of the fan or half the height of the fan. But I don't know if that was just an approximate rule of thumb, or if there was a good reason behind it (or if I'm even remembering correctly!).

I have been told by a fan expert that a fan should have space in front of it equal to the depth of the fan blades. The depth of fan blades on a 25mm think fan will be slightly less 25mm. Then again there are fans where they are substantially less than 25mm such as the new Noctua PWM fans.

The Habey is a great little case. Here is how I built my EMC-800 based htpc:
viewtopic.php?f=8&t=63014

Similiar cpu - i3-2100T - but fanless using the coolpipe and some heatsinks.

I think the Kozuti is you best choice. It is uses a thin, so it will require less breathing room. Also it's fan is located under the fins, so that should permit it to do with substantially less breathing room.

Also, they still sell the Zalman "flower" cpu coolers. They aren't that bad if you set them on low. They are breath around the sides... though even with them that looks like a tight fit.

I saw that build when you posted it---very nice! Unfortunately for me, those heatsinks effectively make the case much larger, and what I'm going for is small. Not sure it would pass WAF.

Well, I ultimately went with the Big Shuriken 2 Revision B. Overall temperatures are a few degrees higher than the stock Intel heatsink, but the system is overall much quieter. After installing, I actually went into the BIOS and bumped the fan speed setting down another notch or two. In other words, I changed two variables. So it could be either lower fan speed and/or insufficient "breathing room" for that fan that is causing the higher temperatures.

But the system is virtually silent. I can hear a tiny bit of fan noise if I put my ear up to the case. But at any other distance from the case, it can't be heard. So I have practical silence, and over a couple weeks' use, temperatures haven't gone above 55 degrees Celsius, so I say good enough. What's kind of strange is the idle temperature seems to fluctuate a lot, anywhere from 45 to 50 degrees Celsius throughout the day. I haven't spent any real time analyzing this, because it never gets too hot and it's silent (like I said, good enough).

Now that you installed it, do you know if the Noctua

The Big Shuriken 2 Revision B is 58 mm with the stock fan.

The Noctua NH-L12 is 66mm high with just the bottom fan. When running with just the bottom fan, it doesn't need any headroom, though it would not be difficult to cut a hole in the top plate of this case and add a filter to it, to give it more breathing room. See
http://www.performance-pcs.com/catalog/ ... ts_id=2275

You might want to do this anyway, even with the Big Shuriken. If you want to know the best way cut the hole, let me know.

Now that you have installed the Big Shuriken do you think it is 65mm or 66mm. If 66mm, it looks like you might be able to shoe horn in the Noctua NH-L12.

So, is there enough room for a Noctua NH-L12?

I still don't know how much clearance is in there. I agree, cutting a hole in the top of the case for more ventilation would be ideal. But, as I'm using this as a HTPC, it sits idle 99% of the time, and temps are reasonable. And I don't trust my aluminum cutting skills enough to cut a hole and keep it aesthetically pleasing. At all times, the case is actually quite warm to the touch; not hot, but noticeably warm. But I whipped up a quick script to log temperatures, and even when we are watching movies, temps are fine. And I have the fan dialed down in the BIOS, so it's effectively silent (can only hear the faintest "whooshing" when heat is one foot away or closer).

Having said that, I'm sure the components would not survive if this thing was running at any significant CPU load for long lengths of time. A few weekends ago, I walked right past where this HTPC sits, and thought I smelled a faint burning odor. I had just completed the building of a pair of DIY speakers which were also setting in the same vicinity, so I attributed the smell to the speakers. That night, we watched a movie or something on the HTPC, and there was some random freezes/pauses in the video; that never happens, so when the show was over, I walked over to the unit to pull out the keyboard and start looking for rogue processes or something on the box... several programs, including the MythTV backend process, firefox, and a few others were all consuming 100% CPU. The Big Shuriken fan had ramped up to full speed, as was quite audible. CPU temperature was over 90 degrees Celsius. And the case was too hot to even touch! I didn't know what was wrong, so I rebooted. When the system came back, all processes were normal, but I kept the fan on full speed to cool it off. When the case was safe to touch, I removed the top plate to speed up cooling.

I later found out that day had a "leap second". The Linux kernel's handling of this was buggy, and it caused several programs to go haywire and jump to 100% CPU load. My temperature logger indicated that right at 7:00pm CDT is when it happened, and I didn't address the issue until midnight or so!

In hindsight, I don't know why I thought my speakers would have emitted a burning smell (they were from a kit where all I did was glue and screw, didn't even use any paint or stain). The system has worked just fine ever since... but I may have shortened the life of some of those components; only time will tell.

Because you have a nice top plate, cutting a hole in the top is relatively easy. Take another look at the link I gave you, those fan filters cover up the edges and look very classy.

After some trial and error, following bad internet guidance, I figured out how to do this right. If you change your mind, send me a private message and I will share what I learned.

What I would for starters with your case, is to first see if you can buy a replacement top... and work on the separately. When you got it right, then swap it for the current one. One option you will be able to retain with such a setup, is that using the same holes that the filter uses, you can at any time you want, place a fan on top of the plate, and place the filter over that.