cooling a computer room

[jeffw_00]

My little high-tech startup company in MA keeps its 10x12 computer room cool by using three portable 9KBTU coolers plus (when running) the building A/C. The room temp varies from 80DegF to 97DegF at the warmest point (right above the greatest concentration of computers), which is acceptable. It's a hack, but when it was started the funds to do it right weren't there, and the coolers were only $450 each. Now we're moving, and we have an opportunity to ask for a dedicated cooling unit in a room in our new space. But I'm not sure what to ask for.

How do I translate our current situation into tons of cooling?

Is there more than one solution? Which is the most cost-effective?

Thanks
/j

[whec720]

Get a Liebert. Don't let anybody talk you into otherwise. Go to www.liebert.com and use the search to find a local rep. Add up the wattage of your server equipment. I can't exactly remember, but off the top of my head, one watt is equal to 368 btu/h. That is why your server load is so important. You'll need those numbers when you talk to a Liebert rep. Hope this helps. Good luck.

[d_griff]

Get a Liebert. Don't let anybody talk you into otherwise. Go to www.liebert.com and you the search to find a local rep. Add up the wattage of your server equipment. I can't exactly remember, but off the top of my head, one watt is equal to 368 btu/h. That is why your server load is so important. You'll need those numbers when you talk to a Liebert rep. Hope this helps. Good luck.

i agree..liebert is a good one..get something rated to run in your low temp in the winter,and has humidity control..get a salesmen to come out and look it over

[bustawrench1]

Definitely Liebert.

[barty]

http://www.apcmedia.com/salestools/SADE-5TNRKG_R0_EN.pdf

Cheers

Richard

[roaddog]

I believe one watt is equal to 3.413 btus per hour.I hope this helps in figuring your load requirements on your server room.I also agree with previous post in regards to choosing a Liebert system.

[big johnson]

Liebert all the way, but get a free standing model with remote condenser. Don't let 'em put the evaporator in the cieling, they are a real pain to work on and you have condensate issues to deal with, like leaks on your expensive computers.

[a/cpro]

Liebert All the way.they are easy to work on and real reliable.
I would go with the free standing direct expansion unit.
not the cieling mounted evap.because if you get a condensate leak it stands more of a chance of danageing computor eqipment.
Joe

[finlay]

In the UK we use alot of wall mounted split units for computer room cooling,
good ones to look at are Daikin, Hitachi and Mitsubishi Electric.
They all do large 10kw wall mounted units (35,000BTU) which are very good for computer room A/C applications.
One advantage of these systems is they are available as inverter units, so cut down big time on electrical running costs as they only run at duty required.

Or use an under floor ducted system, gets expensive with raised floor though.

If you do use a split type stick to wall mounted though, if a water leak occurrs at least it goes straight down the wall.

[whec720]

I believe one watt is equal to 3.413 btus per hour.I hope this helps in figuring your load requirements on your server room.I also agree with previous post in regards to choosing a Liebert system.

You are correct, roaddog. I regret my error and thank you for correcting it.

Steve

[Rickstah]

Liebert makes a fine unit. But I would suggest that you consult with someone who knows computer rooms and data centers to assist you to make sure your equipment is placed in such a way that more efficient operation can be achieved. It is easier, and cheaper, to do it right in the beginning than having to re-engineer such a room.

[apc_ac_man]

Jeff,

Let me throw my 2 cents in here.. Look no further than RI and APC. There are many options to choose from out there but the only 2 names you need are APC / MGE and Liebert. If you are going to do a real computer room and your company relies on that room, go with the best.

[clayb1]

Leiberts are fine, but do you really need one?

Leiberts are "High Tech" and control humidity. Do you need humidity control, or do you just need cooling. You're running 9,000 btu units? Times three is 27,000 btu's, or about 2 1/2 tons. wehec720, below is correct; add the wattage up and convert to btu's and you've determined your current cooling requirements. Sounds like you're growing, so you may find you're self in the same too warm conditions later. How much more might you need, what will be the requirements of future servers (the ones you bought will be obsolete in six to twelve months).

We have several tenants who run straight cooling units for server rooms. We also have other tenants who have raised floor data centers and have Leiberts and another with Data Aires.

[d_griff]

i thought humidity was critical for mostly all servers??

[whec720]

i thought humidity was critical for mostly all servers??

It is. Too low humidity causes static electricity, which is horrible for expensive servers. Too high humidity is obviously bad also for this equipment. IMHO, 45 to 50 %RH at 70 to 73 degrees dry bulb, is ideal. Remember, humidity is relative to the temperature you are at. That is one of the main reasons to go with the Liebert. Plus the fact that they are designed to run effectively in very low ambients.

[TABTech2007]

Hey,

I may not be a service tech or tin knocker but, I agree with both the Liebert Units and the wall mount Mitsubishi or Carrier units as well. I'm an air balance technician but I also design small HVAC systems as a side project. I think if you do go with the wall mount unit(s) you may require more than 1 unit. However they are space saving and effective if calced right. Also, the Liebert units have more "bells and whistles" that may be more suited to your purpose/cause. They are easy to service and very reliable. However you need more space for them. Either way, as long as you maintain the correct humidity (on the west coast it's not much of a problem and rarely considered in the designing). I think you'd need at least a 4-Ton unit for your equipment just based on your temperatures. Keep in mind you may/probably want to "oversize" the unit to accomodate future expansion and addition of equipment. I do wish you good luck though!

[brianm]

what temperatures do server rooms need to be at? From an energy stand point it seems like its sometimes too cool, the building operators will keep it at 65 which is colder than my house.

[Airmechanical]

what temperatures do server rooms need to be at? From an energy stand point it seems like its sometimes too cool, the building operators will keep it at 65 which is colder than my house.


70 degrees is an acceptable temp for computer rooms!

no need for 65 degrees,that will waste a bunch of power!



.

[Carsten]

Hi,

Take what you want, but no comfort air conditioning for flats or houses. because they are disigned for a very high rate of dehumidifying. You have a rate of 70 % for the cooling and 30 % for dehumidifying. And low humidity is bad for servers as written.
Our most computer-rooms have a temperature set by 72 degree. Humidity is set by 40 %. customers who have printers in set 50 %.

I don't know how common our brand in the US is, but maybe you want to look here (http://ats.stulz.com/products/precision-ac/floor-mounted_en.html?myLevel=_0.3.0.0)

And by the way, think of new servers next time and install more than the needed capacity.and think of a breakdown of the air conditioning. we say : n+1. most rooms have one unit running and one unit stand by, or three or more unites with rotating standby units.

[TABTech2007]

Temperatures should run between 65 - 70 degrees for most applications. I find that most IT pros want colder rroms than warmer rooms (for obvious reasons). I have seen lower as well, I was at a project where the room was maintained at 50% RH and 55 degrees, but it was an astronomically large server room. Literally an entire floor of a 10-story high rise!

[Airmechanical]

Temperatures should run between 65 - 70 degrees for most applications. I find that most IT pros want colder rroms than warmer rooms (for obvious reasons). I have seen lower as well, I was at a project where the room was maintained at 50% RH and 55 degrees, but it was an astronomically large server room. Literally an entire floor of a 10-story high rise!

i think the obvious reason they want it that cold is because,

they are computer geeks and they dont know any better!

you could have all 10 floors full of astronomically large server rooms you would

still be better off keeping everything at 70 degrees, and 50% humidity!



.

[big johnson]

Ditto that Airmechanical. They come crying when a freakin router gets more than 68 degrees in a closet. They claim it shortens the life. They repalce it all about every 3 years, how much shorter can it get?

[atmosphere]

The low server room temps ( 62-68) usually come from nervous site managers who want the extra three or four minutes needed to pull that extra bit of hair out of their heads.

The issue is heat DENSITY. That is,
alot of heat real fast in a little bit of space.
Server/data rooms are notorious for that.

Comfort cooling machines are not up to that type of duty. No harm intended, but "to each his own" would apply here.

The need to maintain a PRECISE temp and hum requirement without the DROOP encountered with comfort cooling machines can only be addressed by special precision machines.
Think about it.
How are you going to maintain temp and hum in a 1000 sq. ft. room that requires 7.5 or even 10 tons of cooling.
Now, even more challenging, do it with a 2-3 degree swing and a 5% RH.

A big job for a comfort cooling machine, but run of the mill for Liebert, APC, and Data Aire unit.

This is never the place to save money on equipment.
This is the place to pay for the right machine.

Many smarter men on this site will agree with me on this one.

[bustawrench1]

i think the obvious reason they want it that cold is because,

they are computer geeks and they dont know any better!

you could have all 10 floors full of astronomically large server rooms you would

still be better off keeping everything at 70 degrees, and 50% humidity!



.

I used to do a place where they built servers and routers from scratch. Really cool place, had all kinds of robotic soldering machines which built the boards and some other neat toys.

They had what they refered to as a "Burn Room". This was a big room which had several duct furnaces hooked up to it and they could get the temp up to125*F. They would get a bunch of equipment built and put it in this room, hooked up to test equipment. Then they would seal it up and crank the room up to temp, then power up the equipment and run it full blast for 24 hours. If the equipment survived, it got shipped.

Point is, after that, when some geek tells me that if his server room is 70 instead of 68 it's a major problem, I tend to be a little skeptical.

[bustawrench1]

The low server room temps ( 62-68) usually come from nervous site managers who want the extra three or four minutes needed to pull that extra bit of hair out of their heads.

The issue is heat DENSITY. That is,
alot of heat real fast in a little bit of space.
Server/data rooms are notorious for that.

Comfort cooling machines are not up to that type of duty. No harm intended, but "to each his own" would apply here.

The need to maintain a PRECISE temp and hum requirement without the DROOP encountered with comfort cooling machines can only be addressed by special precision machines.
Think about it.
How are you going to maintain temp and hum in a 1000 sq. ft. room that requires 7.5 or even 10 tons of cooling.
Now, even more challenging, do it with a 2-3 degree swing and a 5% RH.

A big job for a comfort cooling machine, but run of the mill for Liebert, APC, and Data Aire unit.

This is never the place to save money on equipment.
This is the place to pay for the right machine.

Many smarter men on this site will agree with me on this one.

I agree.

I inherited a 20 or so sites with small server rooms where they tore out libert mini mates and put in ductless mini splits. Same capacity tonnage wise, but none of them really do the job right. Every one of those sites is a problem child now.

[D'Laine]

I've serviced many computer rooms in Ontario Canada. In the winter the hum in the base building drops to 19%, and if the computer room is sealed, it might maintain 30%. Never a problem. Even down to 25. Well, except that most rooms aren't really sealed if you look above the tiles or below the floor.

Now in the summer, some rooms move a lot of paper or count bills. Then the hum has to be kept down around 55% or they get stuck together.

If the room temps are from 70 to 76. Still no problems. Today's servers just keep running fine. The trick is to put the perf tiles where the computers' fans suck in the cooling air. The rooms need to be 'balanced'.

If Lieberts get a steady diet of very cold return air, say below 68, then the u-bends on the tube sheets rust out prematurely and you have to scrap the A-coils!

If the unit can't be shut down for an hours service, then the customer needs more redundant cooling.

I'm sticking with this story.

D.

[jeffw_00]

thanks guys - as it turns out - the building we're looking at may already have a dedicated cooler. and FYI - I'm ok with temp up to 95DegF for the equipment 8-}

[clayb1]

My comment about the need for humidity control is based on my experience here in So. Cal. Many of our tenants are using strictly comfort cooling machines for their servers. Those with more critical applications have more sophisticated units e.g. Data Aire.

The thing I thought of later and was mentioned by D'Laine is do you need redundancy? However, as you stated below, and I mentioned I have seen, your computers are running OK at 85 to 95*??? Go figure... No bit rot? So I imagine you don't need redundancy.

[Airmechanical]

My comment about the need for humidity control is based on my experience here in So. Cal. Many of our tenants are using strictly comfort cooling machines for their servers. Those with more critical applications have more sophisticated units e.g. Data Aire.

The thing I thought of later and was mentioned by D'Laine is do you need redundancy? However, as you stated below, and I mentioned I have seen, your computers are running OK at 85 to 95*??? Go figure... No bit rot? So I imagine you don't need redundancy.


a computer room that is designed properly will always leave room for a hvac system that goes down!

100% of all serious server rooms/buildings have redundancy, due to the fact that millions of dollars of data can be lost in an instant!

when temps get to high, or humidity gets to low (static discgarge) is when the quickest damage will occur!

a good computer/server room a/c tech gets to work with the cream of the crop hvac systems, the best ever made!



.

[HVACRoNY]

I agree pay now or pay later. Go with the Liebert. If you are given an option install the computer room in the center of the building with no exterior walls (minimal infiltration). If it is humidity controlled, a vapor barrier is needed. Be careful what ceiling tiles are put in the room they must provide a moisture barrier as well. It is also common practice to prevent the main HVAC unit from affecting the room. Isolate it.Hope this helps.

[propmanage]

After you get in your new room update us on what you find and if you need a change.

[control distributor]

I am a controls distributor in MA. We do not sell AC equipment. I can not tell you what is a good unit. However, I can help you find quality techs to sell and install your system if you need help.

[menaphnx]

you in a 13200 btu unit. i would use a mr slim or a quiteside mini split brand unit made for this kind of app.

[jeffw_00]

thanks guys - checking out the space next week. Honestly in our situation 100% uptime is not critical. If the cooling goes down, the machines go down, work stops for a day, but no one dies or anything.
/j

[airon]

For a "small" server room standard equipment should work just fine. Pull the heat out at the cieling and put the cooled air in towards the floor. Mini splits work well for this.

If you need humidity stand alone humidifying equipment can allways be added.

I think the humidity issue is a bit overblown for todays electronics, (obviously you want to avoid static discharges), The humidity thing is a carryover from the old tape drive issues where it was a highly critical issue. and from the days when a lot of printers couldnt handle the static charges. Now those printers are largely outside the server rooms.. Just an opinion.

A large computer room is a whole different story.

[Crazy4thenucks]

When calculating your heat load, and cooling requirements, make sure you leave room for further expansion.
I would recommend either an APC, or liebert glycol unit, with remote condensor.

[ross]

Jeff I work in the boston area and have done many comp rooms with standard ac we add hot gas bypass and a humidfier we done jobs with 100% back up and with remote alarming and controls if needed find your self a good ac company and they should be able to help you. Lieberts are nice but if you don't have a super cridicail area just go with a standard equipment you can get parts at any supply house