Today's challenge: Cooling a NAS

[The late XV105]

Some of you know that I always have to have an IT-related project on the go. The current one however is a bit unusual.

Background
One of my previous projects mentioned in this forum was to put the RAID1 NAS that is one layer of my data backup strategy, in my garage. The NAS is connected to the home network via buried gigabit ethernet running in protected shield, and the garage and home are earth bonded together in case of lightning strike to either building; hopefully the kit at either end won't get fried. Because the brick-built garage is an unheated outbuilding that gets cold and clammy in the winter and hot and potentially dusty in the summer, I needed to find a way of affording the NAS reasonable environment protection. I did this as follows:


Purchased a Western Digital MyBook World Edition II for the NAS since it uses Green Caviar HDDs with very low energy consumption and therefore relatively low heat generation; so low in fact, that the NAS does without a cooling fan. It was also relatively low cost if my idea didn't work
Purchased a large (60cm x 40cm x 40cm) plastic storage box with snap-on lid in which to house the physically small NAS (not much bigger than two 3.5" SATA HDDs mounted as a sandwich because that is almost exactly what it is). The only holes are two cut-outs in the side of the lid that precisely match the radius of the power supply and ethernet cables. No dust, moisture, or creepy-crawly gets in.
Placed a 1TB USB HDD (used for media streaming) adjacent to the NAS and with as much air gap between the two as I could get
Taught myself the basics of Busybox Linux and use of WinSCP to hack the NAS and write scripts to; monitor HDD temperature via SMART every 15 minutes; send an e-mail and shut down the NAS if either HDD exceeds 56 deg C (max operating temp according to WD is 60 deg C); write a date and time stamped log file entry for each HDD every four hours so I can look for any odd temperature trends or variations between the two; send an e-mail on reboot and let me know if it was after a controlled or power-failure shut down


All hunky dory, great fun to design, learn, and implement, and working beautifully for the vast majority of the time. In winter, even when the garage air temperature immediately adjacent to the enclosure was -6 deg C, the air temperature inside the enclosure was a nice and snug 19 deg C with the HDDs idling at 31 deg C. For most of the year the HDDs idle at about 40 deg C and reach the low fifties when running flat out for a sustained period.

Problem
In summer evenings when the sun is directly cooking the garage, the ambient air temperature adjacent to the enclose can exceed 40 deg C (42 max seen), the HDDs then exceed 56 deg C, and the NAS tells me this fact via that e-mail and then shuts down nicely. My solution today is to switch the NAS back on (or have my wife do so if I am abroad since she gets the e-mail too!) and leave the enclosure lid ajar by a couple of cm at one end. Overheating never occurs in this scenario but it does let dust, moisture, and insects in.

Challenge
How to cool the NAS without fans and filters drawing outside air in to the box and then expelling it?

I want to keep a humidity and dust-tight enclosure that I don't have to fiddle with according to the season, or clean and maintain. To me this implies heat soaks and perhaps sitting the enclosure in a bowl that holds water during the summer (okay, so there is a small amount of maintenance here!) or blowing a table top fan against it, but I'd love to hear some credible and sensible suggestions, please.

For the record the current enclosure is gloss black plastic with opaque lid and it sits on top of a two metre high metal cabinet. The NAS is *NOT* against the wall being cooked by the evening sun.

Yes, I can "buy" another 4 deg C by pushing the shut down threshold to the HDD design limit but I'd rather not do this and in any case don't feel that it is enough on its own.

[green granite]

How about something like this? 400W 12V Thermoelectric Cooler Peltier Plate TEC NEW# | eBay UK (http://cgi.ebay.co.uk/400W-12V-Thermoelectric-Cooler-Peltier-Plate-TEC-NEW-/290550620226?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item43a62aa042)

Or alternatively a PC water cooling system.

[mixture]

Some of you know that I always have to have an IT-related project on the go.

And some of us think, oh no not him again with another Frankenstein project... :E

Option 1/
Replace HDD with industrial grade SSD HDD which will allow you up to -40C to +85C operating temps if you get the right model.

Option 2/
Buy one of those cheap hotel room minibar fridge thingies and stick your gloss black plastic contraption in there. :E


Side note: You may wish to read this Google whitepaper (http://labs.google.com/papers/disk_failures.pdf) on HDD failure rates, especially their analysis on effects of temperature. Whilst there has been some debate on the content of this white paper in some circles (so don't take it as complete gospel), its still interesting reading.

Edit to add:
A quick Google brought out this guy's (http://www.silentpcreview.com/article22-page1.html) home experiments with passive HDD cooling.

[mixture]

Or alternatively a PC water cooling system.

Did your mother never tell you not to mix liquids with electronics ? :cool:

Aah the joys of coolant leaks....as the photo below illustrates, Mr Jobs decided to ignore good parental advice and at one point in time unleashed one model with liquid cooling. Soon learnt his lesson and liquid cooling was never seen in Apple systems again.

http://files.macbidouille.com/news/200708/043.jpg

[Bushfiva]

I don't see how you can cool your NAS without diddling with the case, unless you're prepared to introduce some airflow. If you do add a fan or similar contraption to the box, you can easily filter the air using the stuff sold as an oil filter for cooker extractor hoods, for example.

I did passive cooling a while back on some drives, adding formed aluminum heatsinks which gripped the drives on 3 sides and turned them into true 5" units. Messing around showed that very little passive heat sinking made a big difference. I guess that's no use here unless you're prepared to lose the NAS case.

Since you aren't, you need some kind of environmental heat transport. If you don't want to add a fan to the box, I might suggest a tall vertical black pipe on the top with a filtered opening near the bottom, to get filtered convection running. You can protect the top in a bazillion ways. And cover the box with silver foil.

[Sprogget]

1) Buy a fridge.

2) Stick it inside.

[tony draper]

Yer a small beer cooler like what Bro Draper has,just drill a hole through the side for the cable entry,
Gave some thought to a water cooling system a while back meself but they don't make em for desktop cases apparently

[The late XV105]

Thanks for all the creative ideas Guys. :ok:

I had already found the "cooling project" web site, but not the Google report; thanks for sharing, mixture, as some of it is quite interesting (and some of it quite unexpected).

I have actually looked at two beer fridges already (one Husky, branded as Stella Artois, and one of unknown manufacture) but both cooled the contents far more than I need.

Last night however a friend (whose surname isn't Shelley :)) suggested wine coolers; some wines need chilling but not as much as beer typically does, so the thermostat would likely have a higher ceiling. Sure enough, the first one I found was this one with 18deg C maximum. It is also the right sort of physical size internally, has low power consumption, and is quite inexpensive to buy.

The same friend (a computer hardware guy) also commented however that he thinks I am over-careful with protecting the NAS from the environment it sits in; he thinks that because I have disabled spin down (so the disks are always idling and generating some warmth) they will quite happily survive bitterly cold winters so long as they are shielded from sub-zero drafts. Because I have proven that propping up one end of the box lid is all it needs to get temperatures back inside limits on even the hottest days, his thinking is simply to leave the lid completely removed and stretch some fine denier tights over the top to keep most dust and insects out! Given that overheating only happens in the summer, there is also a wide time period in which to pop the lid back on if I am really worried about cold and damp.

I will admit that there is a simple elegance in this even though it is exactly what I discarded when installing the NAS a year ago and it is not the creative science project that I wanted! :)

So, I will try the tights and if necessary buy the wine cooler!


Thanks again, and I am sure I will come up with another project soon.

XV

[mixture]

XV105,

My physics is a bit rusty but one idea I had was perhaps you could put your hard drive inside a vacuum and so the heat from the room would not travel accross the vacuum.

But then I remembered you might need power and data cables to the outside world.... guess I was never really cut out to be a millionaire inventor. :(

[MacBoero]

Get a cheap drinks fridge, and modify the existing thermostat to regulate to the desired maximum temperature, or get a thermostatic mains switch to control power to the fridge, it only operates when the temperature is higher than usual.

E.g. RS | Process Control | Sensors and Transducers | Temperature Sensors | Thermal Switches (http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=2282557)
This closes when the temperature reaches 50 Celsius. The contacts are rated for 250Vac at up to 8A.

It sounds like you enjoy making things work through computers. So how about these?:
http://thermometer.co.uk/903-usb-thermometer-temperature-stick.html
2 Channel Relay Module - Devantech - USB-RLY02 - Proto-PIC.co.uk - UK Suppliers of Electonics - Robotics - SparkFun - LilyPad - Arduino (http://proto-pic.co.uk/products/2-Channel-Relay-Module.html)

[The late XV105]

guess I was never really cut out to be a millionaire inventor.

There is also the small matter that because I am supplying energy to the HDDs from outside the vacuum and some of that energy will be converted to heat, the disks would simply get hotter and hotter and hotter!

[The late XV105]

Thanks, MacBoero.

Get a cheap drinks fridge, and modify the existing thermostat
Nice idea, and it has the element of a bit of a project about it, but the wine cooler is cheaper than any small (as in smaller than a domestic under-the-counter) fridge I have yet found.

It sounds like you enjoy making things work through computers. So how about these?:

:)

I looked at items like these when I first set out to install the NAS in the garage, but the problem is that it runs Busybox Linux and is not a PC running a flavour of Windows. Additionally, it "receives" USB connections rather than hosts them. All this means is that I was not convinced that I would get them to work, so instead focused on finding a way to do the hack that I described in my first post. This was done with complete success (and not a little self-satisfaction of a neat trick well done, if I am honest) :)

[MacBoero]

How about something like this:
Waeco Mobicool U26 camping cool box Mobicool cool boxes UK (http://www.jacksons-camping.co.uk/waeco/coolbox-t26dc.htm)

[mixture]

it runs Busybox Linux and is not a PC running a flavour of Windows. Additionally, it "receives" USB connections rather than hosts them.

And thus we witness the birth of XV105's next IT project....... learning C++ and using the APIs to knock up some home-brew additional features to his NAS box. Who needs Windows when you've got C++ and a compiler ... ay XV105 :E

[Mike-Bracknell]

Having had one of these fitted in my new bathroom, you could always use one to filter clean air from outside (and it's relatively quiet):

Manrose Chrome & White 25W In-Line Centrifugal Shower Fan Kit | Screwfix.com (http://www.screwfix.com/p/manrose-chrome-white-25w-in-line-centrifugal-shower-fan-kit/41379)

I guess the beer fridge would hammer your green credentials ;)

[Mr Optimistic]

It's obvious: build a new garage with better insulation. Well, maybe place on the nice cool ground against a north wall ?

[mixture]

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