Server Room Cooling - Help with BTU #

[DthInd]

The company I do some computer work for on the side is moving to a new office. He is going to have a dedicated server room. He wants to have seperate cooling system for this room. The building contractors need to know how many btu's he wants for the room.

The room is 15x15x10. There is a single door into the room that will be closed 99% of the time.

There will be a dedicated vent in and exhaust for the room in the ceiling.

He has six mid tower servers doing mostly file i/o. The servers are raid-5 and dont work too hard, but must be up 99.99% of the time.

He will also have a small phone switch in the room.

What is a good rule to determine the cooling needs for the room ?

Thanks for any help you can provide.

 

[QwertyJuan]

It's not that big of a room man... I've seen a small building used fopr a server room, that was roughly 10x10x7 high... and it was planty cool with only a 5000BTU AC in it... you do have higher ceilings, but man... I would think 10,000 BTU's would be more than enough...

QJ

 

[Christopher]

Determine how much electricty the room will consume, usually this is mesused in watts.

Then you can convert watts into BTU per hour.

1 watt = 3.4121416 Btu/hour

Be sure to think about headroom for server upgrades, faster systems usually produce more heat.

 

[rcolbert]

The above advice is excellent. Planning for future expansion is always a must. Six servers don't seem like much, but they could unexpectedly become 50 servers overnight.

Exhausting through the ceiling is excellent. Having cold air introduced low is also good. Through a raised floor is ideal, but may be overkill here.

Layout of the equipment should take in mind expansion and also hot-side/cold-side of the servers. In other words, setup the servers with their backs pointed to the empty space directly below the exhaust. Allow for hot-aisle/cold-aisle if you think that there might come a time when mutliple rows of server racks might be there.

Over the past 8 years we've doubled, and then tripled (total of 6x) the size of our data center, and both times we thought we had created enough capacity. We've gone from several dozen Windows servers and a similar number of Unix boxes to well over 500 Windows servers and ~200 Unix hosts in that period of time. No one saw that coming. Now with blade servers and a very dense server farm for two way searching and matching on the horizon, we're looking at seriously overhauling our environmentals for what seems like the third time since we'd reached our maximum size.

Overkill sometimes is not enough....

 

[sieb]

Virtualization.. I'm mid cycle migrating our hosting servers to VMWare GSX servers, four - six virtual machines per physical server. Cut our server count in half saving us overhauling our server room. The above advice is good, as long as cold air comes in and hot goes out (hotside/coldside), a good airflow will do better than just chilling the room.

 

[feigned]

We're having the same problem at our office with a 10,000BTU A/C unit.

We doubled our volume by opening up a wall to a closet (did some painting and what-not, doesn't look half bad really) and upgrading two servers, with a third on the way.

14x16x10 or so, roughly. BTU just for the room calls for 5,000 and with the four servers and a new fifth one soon, plus our two machines, two test machines, four monitors (two 17", 1 19", and 1 15" LCD, five 2000w UPS's, and including the two of us, we're looking at well over 30,000BTU of needed cooling. I tried telling the other admin we'd need to exhaust all of the heat rather than just pump cool air into the room...I told him to think of the room as a big case and he didn't want to hear any of it.

Anyway, our current piddly-ass unit freezes over on the inside and it's really cool (lol what a pun) to have to turn the damn thing off so the layer of ice that penetrates the entire radiator (?) part has time to thaw out, then turn it back down a bit, rinse and repeat. We're getting another 12,000BTU unit installed in the server portion of the entire office, and I can see us growing even more in the next year. Yay for politics and not wanting to spend the money to do this crap correctly.

 

[HTPC Rookie]

Can't really help with the BTU question, other than to say call an AC shop in for a free estimate and see what they have to say.

I'll toss in something I learned the hard way though to avoid. Whatever size unit you end up with, don't get one with electronic controls, find a good manual (turn the knobs not push the buttons) type.

The electronic ones don't restart themselves after even a slight power loss. We stuck one in our server room window at my last job, and every time the power went a little nuts the Exchange box would e-mail me at home, and send a message to my pager telling me it was shutting down, even though all the servers ran thru the power hit on their UPS. Sucked to be at a club somewhere with a couple drinks in me and have to run back to work. By the time I got there the server room was so hot most of the machines had shut themselves down.

That thing didn't stay in the wall long...

 

[valve1138]

Can't really help with the BTU question, other than to say call an AC shop in for a free estimate and see what they have to say.

This is what I would reccommend as well. There should be at least one HVAC contractor familiar with this.

Last server room I built I gave the HVAC guy a count of how much and what type of equipment we needed to cool it. He came back with a number that left us with room to grow.

 

[da sponge]

Can't really help with the BTU question, other than to say call an AC shop in for a free estimate and see what they have to say.

I'll toss in something I learned the hard way though to avoid. Whatever size unit you end up with, don't get one with electronic controls, find a good manual (turn the knobs not push the buttons) type.

The electronic ones don't restart themselves after even a slight power loss. We stuck one in our server room window at my last job, and every time the power went a little nuts the Exchange box would e-mail me at home, and send a message to my pager telling me it was shutting down, even though all the servers ran thru the power hit on their UPS. Sucked to be at a club somewhere with a couple drinks in me and have to run back to work. By the time I got there the server room was so hot most of the machines had shut themselves down.

That thing didn't stay in the wall long...

If you're getting a window type unit, then ok. If you get a seperate system w/ condenser & whatnot that's hooked into the building's water supply, electronic controls are they only way to go.

 

[mike2323]

The room is 15x15x10. There is a single door into the room that will be closed 99% of the time.

The server room I deal with is 20 x 18 x 10. Single door entry closed 99% of the time. I've no idea what kind of AC unit they have. All I know is it required a crane to lift it on top of the building.

 

[HTPC Rookie]

If you're getting a window type unit, then ok. If you get a seperate system w/ condenser & whatnot that's hooked into the building's water supply, electronic controls are they only way to go.

Large systems that use seperate condenser / air handler units (built-in systems) use external t-stats.

The electronic t-stats have a NVRAM chip inside to keep the settings, and start the unit back up when the power comes back up.

You can't get mercury-bulb t-stats anymore, that did away with most non-electronic t-stats. But there are still bi-metal strip t-stats out there, usually the cheaper non-programmable units. Those you would never have to worry about power outs or dead batteries with.

 

[rcolbert]

Virtualization.. I'm mid cycle migrating our hosting servers to VMWare GSX servers, four - six virtual machines per physical server. Cut our server count in half saving us overhauling our server room. The above advice is good, as long as cold air comes in and hot goes out (hotside/coldside), a good airflow will do better than just chilling the room.

We're running a lot of ESX. VMware is great. Unfortunately you can't virtualize everything. Match and Search engines tend to use the whole server, and in our case need to be deployed in pools of 20-50 machines in order to keep the entire database in RAM. Exchange servers hosting a thousand users each are also bad virtualization candidates, as are full-desktop terminal servers which also run at the full capacity of the box.

However, VMware has really helped out for dozens of servers and especially dev and qa server farms where we could get away with it.

ESX server on a Proliant 585 with tons of RAM can easily replace a dozen application servers, and in many cases more.

Also, if you haven't already, check out virtual center. Virtual Center makes Vmware about 100% more user friendly and flexible. It's their true killer app of the year.