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

insulation

[mabu]

You can use standard window units - but the key is insulation - you have to have a very well insulated and sealed room. I built my own server room by adding two additional layers of insulation on to the existing sheetrock (styrofoam with a plastic vinyl 4x8 sheet paneling and then putting silicon on all the seams, then using window units (with a backup unit). I can keep the room at a constant 61 degrees F with two full height racks running with a 8000-12000 btu 220 window unit.

Remove the heat

[Phroggy]

The best idea I've seen is to use enclosed racks, sealed with weatherstripping except for vents at the bottom, and put a duct in the top that leads to an exhaust fan on the roof. Now you're not trying to cool the hot air produced by the servers; you're removing the hot air produced by the servers. Cool air from the already-air-conditioned room will be sucked up through ventilation at the bottom of the rack to keep the servers cool. And since your existing AC doesn't have to cool all that hot air, it should be able to keep the room temperature down to 20C.

Note that this is a long-term solution in terms of lower energy costs. I have no idea what it would cost up front to implement.

Dual Air Conditioning Issues

[billstewart]

Steven Wright has a line about "I bought a humidifier and a dehumidifier and put them together in a room to fight it out." That was what happened with our dual A/C system in the first computer room I helped build, back in the early 80s to support our VAXes. We had a couple of chilled-water Liebert units that were bigger than the computers, and management had decided to get two of them so we'd never lose cooling. Turned out we couldn't actually run them both at once, though I don't remember if they were fighting more about temperature or humidity - one unit would be pushing a bunch of cold dry air under the floor, which would blow into the sensors of the other unit, which would push a bunch of warm wet air under the floor, etc. And any time there was a power failure, the A/C wouldn't automatically restart, but the VAX would, so if this happened overnight or on a weekend, the room would reach 130 degrees (F), at which point the power system would decide their might be a fire and shut everything down until the room got cooler - which would take a while, since it wouldn't let us use the A/C. So we'd get in on Monday morning, have to open the back doors to the lab and go steal desk fans.

My late-90s lab had much smaller equipment - a bunch of routers and PCs in an enclosed office - but it still generated enough heat that we needed extra A/C. We didn't own the building, and the A/C unit that the landlord put in the ceiling would occasionally ice up and start dripping water onto our desk, but fortunately it usually missed the rack. For a couple of weeks during one of the A/C repairs, they gave us a big standalone thing that blew cool air into the room and warm air out through the ceiling ductwork. It had enough room in the top to chill a couple of bottles of wine, so our winetasting that month did whites.

Go Geothermal!

[haemish]

I once had to do essentially this in a slightly unusual situation: the server room was by an outside wall, and on the other side of the wall they were about to put in a new lawn. We just dug down extra deep (about 4 feet) and got about 100 feet of 6' diameter corrugated plastic drainpipe (intended to be buried, the corrugations make it somewhat flexible), covered it with dirt+lawn, and finally put a fan on one end and recirculated the server room air through this. Only had to buy a fan and the pipe, and the long-term power bills were almost zero (just the fan). And it's incredibly reliable.

Re:Antarctica

[nbert]

Since a few years we hear about people putting everything in an aquarium filled with vegetable oil. The only downside is that the oil creeps up the cables going out, so you have to wipe them from time to time. Never heard of any larger setup of this kind, but it would be interesting.

And before someone mods me down consider this: The original article lacks info about just everything one would need in order to give reasonable advice: Location (local temperatures), heat output (amount of systems and what kind they are of), size of room and so on. So don't blame me but the guy who failed to articulate his question in a way that one could help him (plus the one putting it on the front page).