Slashdot Mirror
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?"
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
Vacuum cleaners suck. Kings rule.
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?
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.
Forward, retransmit, or republish anything I say here. Just don't misquote me.
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?
It isn't a lie if you belive it.
Sue the power station for lost revenue/downtime.
If you're looking at dry ice and knocking holes in the walls, you're almost out of options. Save the hardware.
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.
I read the internet for the articles.
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.
09f911029d74e35bd84156c5635688c0
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.
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....
Power Corrupts,Absolute Power Corrupts Absolutely, leaving one person(group)in charge is absolutely corrupt.
You should have thought of this LONG before now.
Why do you host at a place without dual power companies providing power?
Why do you host at a place without dual redundant A/C on EACH power provider?
Why do you host at a place without dual redundant power generators?
Just how "essential" is the stuff you're hosting?
How is it important that you're "on leave from [your] Gov't job"?? That's no excuse (if it was meant to be) for not jumping on top of that HUGE MASSIVE INSANELY rediculous situation your servers are in right now, and taking the steps to fix it the very first day you started at that job.
in fairness maybe you started today, but i think somehow that you've had time to fix this before now.
Buy two big high output fans, the biggest and most powerful that will fit in the door to the server room. Stack them one on top of the other in the door. Face the one on the bottom in to suck relatively cooler air from the floor into the server room, and the one on the top out of the room, to suck the relatively hotter air at the top of the room out. This will work better if you can get the one on top all the way to the top, and seal the rest of the space in between. Also, this isn't going to be as effective as the server room opens onto a long hall, as if it opens onto a big room.
If the server room is on the bottom floor of your building you could also prop open the fire doors on the stairs so all the cool air in the building flows downhill to the floor your computers are on. This is going to be a fire code violation if your building is tall enough.
As water usually comes to the building through undreground pipes, it attains about 50-60 degrees farenheit.
Bring a hose into the room, and use a car radiator or cheap, large coil of copper tubing, and run the water through that and into a drain. Blow air through and you've got a fairly inexpensive way to cool.
Water is not expensive, but you could go through hundreds of gallons a day. Limit your water usage by watching the temperature of the incoming and outgoing water, and placing a valve in the outlet. If the temperature difference is great (60 in, 80 out) then let the water through a bit faster.
You could even set up several of these in series so you can cool different portions of the room. Think about how the air circulates - if you can get the air to go clockwise around the room the fans will use less energy, and the whole room should reach the same temperature.
Of course, it goes without saying that you need to be careful not only of leaks but condensation. Place buckets under the coils, and connections/transitions - make sure you have no leaks, and dump the buckets occasionally.
If the cooling isn't great enough, put a set of coils just after the inlet into a trashcan of water and dry ice.
Note that it may take several minutes of water running before you actually get the cooler water, depending on how much of the building it has to travel through to get to you. If it goes through a lot of the building, you may not have very cool water at all, as it'll attain the temperature of the building. Give it a good half hour or hour at full blast and measure it to see what is possible.
-Adam
I hope he doesn't... a window in a server room is highly insecure, and it also leads to fluctuating temperatures in the area of the window.
Of course, with a fan and some cheap ducting you can have a similar effect. You'd need a much more powerful fan to do it though.
A serious suggestion? Generators and portable AC units. I've seen them used by a former company when the AC was inadequate in the server room. They were about 1.3m tall and had large white hoses coming out of the top to make them about 2m tall overall. You had to feed them water on a pretty regular basis since they were not closed loop AC units, and you'd also need generators to give them power. It worked in a pinch though. No need to cut holes in the ceiling either -- they just vented into the room (suck air in from the bottom, output at the top).
"So, when Transmeta Corp. came along in early 2000 and announced a processor that was 85 percent to 90 percent of the mobile Pentium's performance with a fifth of the power consumption, it was a no-brainer," Hipp said.
The result was the RLX System 324, a blade configuration that packs more punch into a smaller space than any other server on the market?up to 336 blades in a single, 42-unit, industry-standard rack (..)
It goes without saying that a box that necessitates 80-90% less power than an equivallent Intel or AMD, produces less heat. (from an older but insightful eWeek article.)
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.
buy several refridgerators/freezers, and leave the doors open!
Quidquid latine dictum sit, altum sonatur.
A closed loop with a swamp cooler outdoors would solve the water wasteage, assuming the relative humidity isn't too high.
Please consider making an automatic monthly recurring donation to the EFF
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.
Help us build a better map!
Submerge the entire room in mineral oil.
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.)
-- I'd say your post was about 3 monkeys, 18 minutes.