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 :-)

[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.)

Rent big truck generator & run whole building

[StormForge]

It's pretty affordable to rent a huge generator system mounted on a tractor-trailer. Probably have plenty of power to keep everything running. Maybe make the power company reimburse you even?

AC onna truck

[PapaZit]

First of all, you should have thought about this BEFORE now. If you're a decent webhosting company, disaster planning and recovery is as essential to your business as spare hard drives.

That being said, there are often companies who can provide air conditioning and/or generators on a truck. They'll block off a doorway or the loading dock and pump the air in through there. If you have a little more time (and appropriate permits, etc.), they're often willing to run temporary connections into your forced air system.

Whenever they do HVAC work on our building, they have the trucks set up and waiting. We have a few too many computers to even survive with "just the essentials" if the AC goes out.

Nix the Dry ice

[jandrese]

I'd nix that Dry ice idea. Most server rooms don't have paricularly good ventilation despite the large amounts of A/C in use (it's mostly recirculated air). Releasing large amounts of CO2 into the room might just turn your server room into a silent deathtrap.

Re:Nix the Dry ice

[zulux]

Releasing large amounts of CO2 into the room might just turn your server room into a silent deathtrap.

But if you'r....say 6 foot three inches and your PHB is say... a dwarf.... well......

Invite him in, and when he falls over with his eyes bludging out.... run!

most important of all --

[fraxas]

Ask Slashdot.

But seriously -- be sure to consider the relative risks of keeping your server room up versus taking it down and waiting. If you take it down now, you're guaranteeing yourself downtime, but you can come back online as soon as the substation comes back.

If you try to stay running, you're not guaranteed to have downtime, but if you do it'll be intense, because you'll have damaged hardware to deal with.

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.

I'm thinking what you need to do here is..

[Ophidian P. Jones]

Submerge the entire room in mineral oil.