Cost-Effective Server Room Air Conditioning?

at0mic26 writes "I am currently tasked with finding a cost effective solution to our 30+ degree Celsius server room. The only air conditioning currently provided is a single duct pipe from one of two air conditioner units. I was thinking of stealing air from the second air conditioning unit with some sheet metal work, but it likely will not be sufficient — and would not have tolerance for both AC units being offline for any amount of time. An ideal supplemental portable AC unit is what I am after, however I'm finding it cost prohibitive, with $600+ humidity controlled AC unit, plus 20 amp socket requirement, plus contract work to make a hole in the wall for outside drainage so that the unit does not flood the place. What sort of successful cheaper air conditioning solutions have you come up with?"

Comments

Simply this...

[actionbastard]

There are no cheap A/C solutions. Portable home units lack the tonnage to adequate cool even a small bedroom, let alone a room full of fire-breathing servers. Industrial portables for 'spot' cooling, that have sufficient tonnage start in the low $10K rang and quickly move up. My suggestion is to get an A/C pro to do up the spec for you and then bid it out with guarantees and such in the RFP.

Re:Simply this...

[linear a]

Sounds like you have more time than money. If you can't afford the cost to beef up the A/C, you can use some of the techniques used in server room design. If you can, take the cold air and put it directly into your hottest (or most expensive to replace maybe) and add partitions to channel the cold air where it will do the most good. Simply mixing a stream of cold air with the warm room air is not efficient. Put the limited cooling where it does the most good, don't let the cold air mix with the hot air, try to channel the hot air away from everything. As an added thought, and exhaust fan somewhere where it is hottest might do considerable good.

Re:Not much you can do

[NFN_NLN]

Dry ice and a fan?

This is not recommended:

Due to the health risks associated with carbon dioxide exposure, the U.S. Occupational Safety and Health Administration says that average exposure for healthy adults during an eight-hour work day should not exceed 5,000 ppm (0.5%). The maximum safe level for infants, children, the elderly and individuals with cardio-pulmonary health issues is significantly less. For short-term (under ten minutes) exposure, the U.S. National Institute for Occupational Safety and Health (NIOSH) and American Conference of Government Industrial Hygienists (ACGIH) limit is 30,000 ppm (3%). NIOSH also states that carbon dioxide concentrations exceeding 4% are immediately dangerous to life and health.

Cost of doing business

[TJ_Phazerhacki]

You can cut corners - but if a 20 Amp circuit + $600 for a cheap unit is scaring you off, you are out of your league.

Bite the bullet and get what you need right the first time, because the repair and replace if it isn't done correctly will make $1500 seem like a drop in the bucket...

Re:Remove the heat

[mcrbids]

Your solution *sounds* nice, but in fact, may drive cooling bills UP.

Where I live, it's routinely over 100 degrees (Yup. Ima 'merkin!) outside, today is expected to hit over 110. In order to provide a net savings, the hot air coming out from your server rack has to be even hotter than that, otherwise you're venting 90 degree air outside, then having to compensate for this by cooling down 110 degree air as it gets sucked into your building.

And this problem is exacerbated if there is relatively high humidity. (EG: Florida) Then, not only are you cooling down the air, you're pumping water out of the air, and since OP mentioned water drains and "not flooding" the place, this may well be him.

Now, if you're in an area where high temps are the exception, this may not be much of an issue. But it sure wouldn't work where I live.

OP: Here's what you do: Go to three reputable contractors. Get three quotes for the job. Get references for each contractor. Present this information to your boss.

If he/she can't handle that, you need to move on anyway.

Re:Turn off the servers

[raddan]

Not to mention-- adding another AC unit without that unit being tied into the same controller will cause problems for your AC units. They'll be turning on and shutting off more frequently. This will greatly affect the life of your AC units. If you're a hardware hacker, you can probably add capacity on the cheap by hacking your thermostat to coordinate multiple units. Otherwise, you really do just need to pony up and pay for the AC upgrade. Cool air is a basic business expense nowadays. If the people writing your budget don't see it that way, then your company is in trouble.

HVAC design for Server rooms

[Elfich47]

You have to ask the following questions when designing a cooling system for an HVAC system for a server room. The conditions are significantly different than cooling for an office.

1. What is your total kW consumed in the room.

2. What is the cooling strategy you want to employ?

Passive cooling - use a fan to dump the heat out of the building.
Active cooling - Install an air conditioner with an external condensing unit to dump the heat outside.
Alternate cooling - Dump the heat into the rest of the building during winter in order to saving on heating costs.
Any of these options have good and bad points: expense, humidity control, thermostat control, expense of use, required backups.

3. How is your server room arranged?
Is everything just thrown in the room?
Are you running a hot isle/cold isle environment?
Do you have a raised server floor so you can pump cold air into the bottom of the racks with a ceiling return?
Do the racks have fans to draw air from front to back?

4. What is your current cooling capacity that is dedicated to that room?

The last server room I designed was 500 square feet and consumed roughly 14 kw (28 watts/sf). That is roughly 4 tons of sensible cooling. To purchase a system capable of 4 tons of sensible cooling you will need to purchase a system capable of 5-6 tons of total cooling (Skipping the lecture on Sensible vs Latent vs Total cooling). So have you have just spent $4,000 in materials. Assume your costs will double for installation. Plus another couple of grand to have an actual engineer come in and design a system that will serve your specific needs.

The question is not one of getting the heat off the chips. The heat is making its way into the air just fine. You need to get the heat out of the air (and the room) and out of the building. If your room is exceeding 30C I would assume your racks are easily running 5-10 degrees hotter. That is getting into the range where your equipment is going to start shutting down.

Now onto your problem: $600 budget. Option: Throw a patch of your choice at it. A roll-a-way unit from Wal-mart or target where you can push a heat rejection duct out of the building, for example. This is a patch, not a solution.

Assume you are going to have to pony up $10,000 (USD) to solve this problem.