Emergency Cooling with Limited Power?

Nos. asks: "I work for a small webhosting company (I'm on leave from my Gov't job) and we've started having some power problems. Actually someone managed to blow out the substation powering the area so we're piggy backing off another one, and they're slowly powering more and more things off. Elevators, lights, etc. are gone. Since the building we work in has a few IT company's working it in, they're trying as hard as they can to keep the A/C running, but its not looking good. As such, the possibility exists that our server room could get very warm, very quickly. Since we've already powered off everything that's not essential, we're starting to look at ways to keep the room cool without using a lot of power. Generators an small A/C units are a last resort as it would mean holes in the walls. The only thing we've been able to come up with is dry ice and some small fans to circulate the air. Of course this is happening as we're heading in to a week of over 30C days. Does Slashdot have any ideas?"

Comments

Keep ordering icebergs off Ebay :-)

[Gruturo]

No, seriously, I don't have any exceptional cooling method to suggest, so I'd focus on reducing heat production instead of dissipating.

1) Power off every non-essential item (You say you've already done it, but have a second look at what's REALLY essential. Got 2 firewalls in cluster configuration? Keep only one! Pull out that hot-swappable hard drive from your raid-1 array! - Warning: will have a long-term impact to your uptime)
2) Ventilation. As long as you're not in Saudi Arabia, air from outside is cooler than what the server room would be without air conditioning.
3) People! Humans give off a lot of bodily heat (Matrix jokes apart). Keep people off the server room unless it's really necessary
4) Lighting - Use compact fluorescent instead of incandescent (they run much cooler, too) and turn them off when it's not needed
5) Shadow - An incredibly effective way of bringing down room temperature by as much as 10 degrees. Might not apply to you, but if you are in a very exposed side of the building, or under the roof, you might benefit greatly from it.
6) (Illegal in many countries) Cooling with running water. Extremely effective, but a huge waste of water
7) (a bit extreme) Replace the less loaded and less critical servers with a couple laptops you might have lying around. I'm writing from a 1.6Ghz Centrino laptop with 512MB DDR - it's a lot more powerful than some of the servers I have at work. (and laptops tend to be terribly stable).
Its power supply is rated 65W!
8) - If all else fails, decentralization. Put the remaining servers farther apart (the heat in a single 42U rack filled with equipment is tremendous, while if you spread the content all over the room it will be more bearable for the hardware). Get a few very long network cables and take something out in other rooms, also (even if only the server room is ups-protected, it won't make a big difference when power goes down for a day).

btw fp :-)

Re:Keep ordering icebergs off Ebay :-)

[(H)elix1]

Dang, fp and spot on... checking to see if my cube froze over...

About 10 years back we had a similar problem. The main AC unit failed and we were watching the mercury rise after we did most of the above. We were able to bring portable air conditioners which pushed the hot air though 1' plastic tubing to the cool outside air. It worked, no holes in the wall. The generator adds a little difficulty, but nothing long extension cords wont fix.

Don't forget to pull the ceiling panels if you can - assuming the air is cooler. Was for me.

As for dry ice - don't forget that sublimes to CO2. I suspect every door/window is open right now, so less of a ventilation issue. Blowing a fan over what ever you use will help.

Re:Keep ordering icebergs off Ebay :-)

[drlock]

2) Ventilation. As long as you're not in Saudi Arabia, air from outside is cooler than what the server room would be without air conditioning.

I grew up in the tropics, most of my life without A/C. You'd be surprised what a box fan (that is what we called them anyway, 2 ft square fans that sit on the floor. They don't use a lot of power.) in the doorway can do. If you want to get really fancy, try and force air circulation: Find two openings to the outside world (ie, window and door or 2 doors). Open one and put the box fan in the other. If you put the box fan in a door put cardboard above the fan (ie seal the rest of the door), so the air doesn't simple circle around the fan.

6) (Illegal in many countries) Cooling with running water. Extremely effective, but a huge waste of water

Or if you don't want to run water, put a large pool of water (think kiddy play pool) in front of the fan. Water evaporating of the surface will act as coolant (same idea as running water, but requires more surface area and doesn't give a constant supply of cold water.)

dryice

[JDizzy]

If you do decide to go with dry ice, make suree to have a good supply of fresh air to wash over the ice instead of letting the dryice evaporate in the data-center. What happens is dryice melts and turns into carbon gas, which makes humans passout from a lack of oxygen. It is even possible to die as this would be comparable to running the exhaust of the car with the garage door down. It would fill the room full of noxious gas. So the trick is to use the dryice in conjunction with a heat/cold exchanger to cool the air in the room. Then again, punching holes for the generators doesn't sound like such a bad idea any more huh?

Re:dryice

[Tom7]

The noxious gas in the exhaust of a car is carbon monoxide. Dry ice is solid carbon dioxide. But indeed it can cause asphixiation.

Re:dryice

[gazbo]

...as this would be comparable to running the exhaust of the car with the garage door down.

Not quite. Yes, if you displace enough Oxygen with CO2 then you can asphyxiate. However, what makes car exhausts so lethal is the carbon monoxide. CO actually has a much stronger affinity to haemoglobin than CO2, so rather than dying because there is no Oxygen, CO will actively displace Oxygen from your bloodstream, even if there is plenty present in the atmosphere.

Of course, this is not such a problem in modern cars with catalytic converters, but still.

Re:Rent big truck generator & run whole buildi

[bofkentucky]

CAT Entertainment services can have a truck anywhere in the US in 24-26 hours with a complete setup. GE Energy Services also rents truck generators 6KW-22MW and portable AC and chiller systems. Looking at their locations, they should be able to reach anywhere in the US in 8-12 hours.

Emergency where I work

[haplo21112]

We have these things called "movin' cools" basicly A/C on wheels...it does need to be plugged in, but you could run it off a generator and a long cord....

They have a Dryer hose like outflow pipe for the hot air which we can connect at various points to the sent system...you could probably micky mouse it to your vents with some cardboard and Duct tape....

Water Ice

[the eric conspiracy]

An insulated tank with water ice (don't use dry ice because of the CO2) and pumping the cold water through a couple of car radiators with fans blowing air through the radiators is probably the best you are going to do. Ice is very useful because it has the heat of fusion and a melting point of 32. The heat of fusion will keep the tank at 0 C and give you a good temperature difference between the radiator and room for a good heat flow; the heat of fusion gives you a good heat capacity. You can probably estimate how much ice you will need per day based on the capacity of your air conditioning equipment and it's duty cycle. 1 ton/day of ice is roughly equivalent to 12,000 BTU/hr.

It doesn't work that way

[Baloo Ursidae]

Assuming you live in a subarctic climate like Portland, OR, consider this: You come home from work in the middle of winter, you turned the heat off before you left. You live in a cheap rental apartment downtown in the basement. You get home, and the apartment is cold. You've got snow up over your windows. You go into the kitchen. Electric stove (turned off), fridge (on). You open the kitchen door. It's warm. Why? That big coil under or behind the fridge is the exhaust end of the cooling system. The fridge heated the room.

ObKarmaHit

[TitaniumFox]

Like most, you'll point out what is wrong with a plan, but you don't have a proposed solution to the problem you've pointed out. I'm sure your supervisors must be happy all the time.

The proposed idea isn't a bad beginning.

If a person is already going to go the route of car radiators and fans, why not spring for a cheapo (so-many-gal/min) electric water pump at TehH0m3Dep07 or the like. A car's cooling system theory is already engineered for you. All you have to do is apply different temperature gradients. This idea has already been alluded to here.

(We are talking about a business or several businesses who are all concerned with a solution to their problem, and is probably willing to put about 500 bucks towards it. I assume they have people they can task, too.)

Open Source, Enterprise-Ready, Multi-platform Cooling System

BOM:
1 50-gal Rubbermaid trashcan (the yellow kind)
2 cheapo car radiators
1 electric water pump (however consumer-ized you need)
1 box-type fan

Method:

Wire-tie one radiator to the exaust of the box fan. Connect the two radiators together with an appropriate amount of hosing, the pump between them on one side. Fill the radiator/hose/pump system with water. Put the loose radiator in the trashcan and fill it with water and ice. Start the pump. Start the fan. The loop is closed, and water consumption is based on ice consumption.

Scoop water from the trashcan as the ice melts. Add ice as necessary.

This idea is GPL'ed.

This is simply a source of cool air. Not huge amounts, and not -20C, either. It'll have to be applied within a framework of air entry and air exit within the server room. A workable idea might be to put the radiator/box fan blowing into a room while other fans were concentrated on moving hot pockets of air around and out of a different door. Modify as needed. Replicate as often as you want. There's no tech support.

(Finally: Yes. I've actually built one of these using 2 Hummvee radiators, a box fan, and an electric pump from a tracked vehicle. It kept the temperatures inside an operations tent in Bosnia much cooler than the 110F+ temps we had.)