Everything Else

If you were reading this thread, then you'll know I mentioned upgrading the cooling in my closet. Things have now progressed a little.

First, I got a tool...


And then I removed the particleboard sheet that was just above the door. Lo, no cables or anything to impede progress apart from a buttload of nails. Whomever build this thing really wanted that thing to stay in place.





Alas, removing it caused some damage



So I phoned up my Dad and he scrounged arond for a spare piece of plywood, an afternoon at my parents (including mom's lasagna!) and I've produced this



I left the inner board off, because who cares what's inside the closet. I had some ideas of reducing noise by putting another board on the inside with the holes offset from the ones on the outer one to act as a sound baffle, but since I don't have another piece of plywood and it's weekend it can wait.

Tomorrow I'll go grab some grilles to put on the holes so they look a little less conspicuous.

And did it help?

Not sure, I powered up rimturs and it's been running with only my power (7 vCPUs, 10GB RAM) domU in idle for a while now with machine intake air (i.e. ambient) going from 28 to 32 to now 33. I imagine I can feel some air movement on both the intake (it's low on the door, in front of the machine) and the two output holes though.

I fear plan C (or was it D?) will have to come into effect with forced air movement, this is tricky because I'd need to power the fans somehow and I don't have a solid plan for that yet.

Oh, and if you're curious, there are some pics of my rack (as of 2015-02-10) here

Very nice setup! I envy your soekris, mine blew up in a thunderstorm. And the "monitored" APC PDU is on the wish list as well.

I think you need a fan. But removing heat with just ventilation is hard. But I think you should try.

For fan power you could just buy an el-cheapo 12 volt linear power supply (I'm a purist, no switchers!). It wouldn't have to be much larger than your hand, run it off line voltage plugged into a wall outlet, and it's problem solved!

Pontus wrote: Very nice setup! I envy your soekris, mine blew up in a thunderstorm. And the "monitored" APC PDU is on the wish list as well.

Thank you, and yow! Have you no such things as lightning protection over there?

That PDU is really nothing special, glorified rack mounted power strip. It can turn on/off ports and monitor the (total) output via SNMP though, which is nice. Also, like the console port server, it's got ssh support, but it's got such a slow CPU it's barely usable.

vishnu wrote: For fan power you could just buy an el-cheapo 12 volt linear power supply (I'm a purist, no switchers!). It wouldn't have to be much larger than your hand, run it off line voltage plugged into a wall outlet, and it's problem solved!

Yup, this was exactly my plan, get a small power supply from the not-quite-local electronics store, potentially solder in an IEC320 connector and hide it above the door (there's a nice bit of space there now that I don't have the inner wall panel mounted)

Now for an...

UPDATE

It didn't take long for the machine to overheat again with only convection cooling, even though it does seem to be cooler in the closet than usual (nominally 28 rather than 30 on my trusty wall-mounted outdoor analog mercury thermometer)

I tried jury rigging a computer fan with a spare PC power supply and a 4-pin molex to 3-pin fan connector converter to one of the holes, but that didn't seem to help, it motored up to 34 degrees (intake air) and started howling again. I wonder if that test failed because most of the air came from the second hole rather than pulling from below.

An infrared camera or just an independent thermistor would be rather useful right now, I have no idea if my modifications have been ineffective or the DL160's temp sensors are screwy. Oh well. It's more a fun project to get the HP running now that I got the Alpha to run stably again (for 28 days uptime and counting

What about adding an A/C vent to the closet?

TeamBlackFox wrote: What about adding an A/C vent to the closet?

Not sure what you mean by that, there's a tiny vent near the ceiling that is straight into the (apartment) building ventilation system, it doesn't seem to do much. I couldn't add an A/C unit into the closet because there are no places to vent the output air other than into my apartment and that doesn't seem smart. Besides, there's no space for it.

There are lots of options but I think your best bet is to get an AC-line powered small box fan and stick it in the space above the door. On low speed they don't make much noise.

I think a louvered plate (search for: inlet or return duct) in the door (inlet) and also the panel over the door (outlet) would also help with appearances, they make them in white and they are reasonably handsome.

Example: http://www.homedepot.com/p/SPEEDI-GRILL ... /202542252

I think it's just a case of being a bit more forceful with airflow. You're right that air will choose the path of least resistance, so your fan will likely be pulling a reasonable amount of air *in* from the other hole. Having two out-blowing fans might be better. Oh, and make sure the input vent at the bottom is big enough too.

Do you know if your building vent is blowing air out or in? If it's in, that's going to cause all manner of problems and should probably be sealed up (gaffer tape would do).

guardian452 wrote: There are lots of options but I think your best bet is to get an AC-line powered small box fan and stick it in the space above the door. On low speed they don't make much noise.

Yeah, that might end up being necessary. I want to try more with PC fans though first.

guardian452 wrote: I think a louvered plate (search for: inlet or return duct) in the door (inlet) and also the panel over the door (outlet) would also help with appearances, they make them in white and they are reasonably handsome.

Yup, got some. I just hadn't installed them yet in the picture. They're not white because I'd have to wait for a week then and couldn't be arsed to

Trippynet wrote: I think it's just a case of being a bit more forceful with airflow. You're right that air will choose the path of least resistance, so your fan will likely be pulling a reasonable amount of air *in* from the other hole. Having two out-blowing fans might be better. Oh, and make sure the input vent at the bottom is big enough too.

Yeah, the bottom vent is about the same area as the two new holes.

Trippynet wrote: Do you know if your building vent is blowing air out or in? If it's in, that's going to cause all manner of problems and should probably be sealed up (gaffer tape would do).

No clue, my guess is out. The stairwell seems to be lower pressure than outside, so whenever I open the window (tiny apartment ) or the balcony door air flows in. The kitchen vent--which is an entirely separate vertical shaft--sucks out, with MUCH more force than the one in the closet. If I put an A4 paper on that one, it'll stay in place. No such reaction in the closet.

duck wrote: Yeah, the bottom vent is about the same area as the two new holes.

Might be worth trying to make it bigger. If it's that similar in size, the fans will be having to work quite hard to pull extra air in, and consequently the output from them won't be as great as it could be. Although saying that, I'd add a second fan first and see what that does.

If you want to keep just one fan, ironically blocking up the second hole temporarily might actually improve things as the fan will then be force to pull air in from the other vents.

Keep in mind that rackmount equipment is generally designed for front to back airflow. Cool air enters at the front, and hot air is exhausted out the back. Your closet setup appears to be using natural convection to create a bottom to top airflow, which won't necessarily help the computers.

I have some small but noisy 1U rackmount servers running in a home-built sound-proof enclosure that's much smaller than your closet. When I first put the machines in there, it took less than 5 minutes for them to generate enough heat to trigger the overtemperature alarms. That's when I realized that despite having font to back airflow through the box, a good deal of air was recirculating inside the box. Heat was being exhausted out the back of the machines into the enclosed space, and then being sucked back in through the front of the machines (instead of room air being pulled into the box). Since it was a small sound-proof box, I was able to put some scraps of foam around the servers to block air recirculation inside it. The machines haven't overheated since. The servers' own fans are enough to pull ambient air in through the front and exhaust it out the back of the box now that there's no chance of recirculation inside it. I didn't need fans in the box once that issue was fixed.

Now, doing something similar in your closet is going to be a lot harder because of the larger space involved. But I'd recommend doing whatever you can to block the hot exhaust air from returning to the front of the closet. Blanking panels of some sort in the rack itself, foam or insulation or whatever around the sides of the rack, etc. Maybe even some sort of panel above the door and rack to block vertical air movement in front of the rack. As you've got it now, air can enter at the bottom of the door and flow straight up to the output vents at the top without ever going through/behind the euipment (if I understand the setup correctly).

Try to guide the hot exhaust air from the back of the equipment to those upper vents and make sure the only path the cool intake air can take is through the equipment.

duck wrote: Thank you, and yow! Have you no such things as lightning protection over there?

It was on a UPS, not sure what happened.

Another thing to consider is some makeshift sides on the rack to avoid recirculation. Think hot aisle/cold aisle.

/P

Edit: oops jpstewart beat me to it.

Wow, thank you, especially jp for the excellent advice (I'm surprised anyone cared enough to comment ). I think that sounds like the path to take if I can't keep the heat in check with just the fans. I'm currently running at test with two PC fans, and so far it doesn't look too good. So far, it seems the fans have slowed it a bit at least. Maybe some baffles and airguides could seal the gap.

duck wrote: The kitchen vent--which is an entirely separate vertical shaft--sucks out, with MUCH more force than the one in the closet. If I put an A4 paper on that one, it'll stay in place. No such reaction in the closet.

Plan Z - move the computer to the kitchen and a kitchen appliance to the closet?

ajw99uk wrote:

duck wrote: The kitchen vent--which is an entirely separate vertical shaft--sucks out, with MUCH more force than the one in the closet. If I put an A4 paper on that one, it'll stay in place. No such reaction in the closet.

Plan Z - move the computer to the kitchen and a kitchen appliance to the closet?

I think plan Z is no more than "move"