Comments on: Data Center Cooling suggestions

By: batman47

batman47 — Thu, 20 Aug 2009 14:58:45 +0000

We are maxed out because the 10 ton unit with dual compressors run in 2nd stage 24/7. No more cycling back to 1st stage. Network Services was suppose to come up with a heat load, not sure if they ever did. They just like to add servers and blame the A/C company when their units can’t keep up.

The decision has been made to install a 10 ton Liebert A/C rack right next to our SAN rack with curtains on either side of the cold isle. We are also having a company build an air channel under the floor to direct the air from the 5 ton unit to the cold isle and replace our perforated floor tiles from the 1980s with new ones that are at least 50% more efficient.

By: drjulianpe

drjulianpe — Thu, 20 Aug 2009 00:53:50 +0000

Controlling airflow is an important point.
How do you know you are maxed out on AC?
Is it because the equipment is overheating or did you calculate the amount of heat being generated in the room?
One kW of IT load is 3412 BTUs. 12,000 BTUs is one ton of AC.
15 tons of AC could cool, assuming it has proper air flow (minimum hot and cold air mixing), approximately 52 kW of load. This load consists of IT power, transformers in the room, lighting, people and building envelope. This also assumes that the cooling units are actually providing 15 tons of air conditioning. Depending on the units and the method of heat rejection the actual cooling may be less than the nameplate value.

By: cando

cando — Wed, 12 Aug 2009 14:34:53 +0000

I am in Anaheim and have a meeting at noon today and another at 2:00 this afternoon. My flight leaves Burbank at 7:00 this evening. Could you send me a sketch of your space and details on your cooling systems? I may be able to make a suggestion from that. I would be much better to see it in person but time is a little short today. You can call me if you like 505 400-0036. I can give you my email on the phone.

By: batman47

batman47 — Tue, 11 Aug 2009 22:26:43 +0000

I’m in Tustin, California. Yes, there are a lot of common sense things that could be done. I agree about plugging the holes and having return ceiling plenum. Recently, we turned on a SAN rack that is putting out more heat than any other rack in the room… on the side of the Data Center that has no return. The only return is on the A/C units on one side of the room. I agree with everything you said, but it is clear to me that we are maxed out with A/C (or will be in the future even after we fix all the other problems) so I was wondering what is the best cooling solution is for the future as we add more heat load…. these new A/C racks or more cooling being pumped into the cold isle? What about redundancy?…. when the 10 ton failed the temp in room jumped to 90. That was before we bought our new SAN equipment.

By: cando

cando — Tue, 11 Aug 2009 17:42:03 +0000

Sounds like your spinning around in circles and so is your air. Your problem is not so much where the air is coming
in the room, but what happens to it after it enters the room. Separation of heated server exhaust and air supplied for
cooling is your best tool against what you are experiencing.
You should of course plug unnecessary openings in both areas you supply cooling air. If you have a space in your dc above the suspended ceiling, it could be used as a return plenum. Connecting as many heat producing devices hot side to this can make a large impact on improving your situation. Obviously there will be some things that cannot be connected, but; you are looking for the low hanging fruit. Install blanking panels in your racks where you have no equipment. (I know everyone says that…few do it!).
Connect your cooling returns to the same return ceiling plenum if you have one.

Try these and see what your results are. Without seeing your site it is difficult to suggest much more.contact me here if I can help more.
Where are you located? I may be close.