Posts Tagged ‘air conditioning’

Global Cooling

Friday, February 13th, 2009

Continuing the Green theme from the last post, I’d like to explain a bit about how our new air conditioning system gives us the best possible combination of performance, resilience, economy and flexibility.

Our Leeds site makes use of a technology called free cooling. Well it’s not quite free (these things cost hundreds of thousands of pounds) but it is a highly efficient way of taking advantage of one of the main features of the UK climate. It’s cold most of the time!

Whenever the outside temperature is less than the temperature of the water coming back from the data centre, we don’t actively cool the water in our chillers. We let the atmosphere do the work for us. So for most day of the year (and pretty much every night) our chillers are doing very little work, but if it does get hot, they kick in to keep the air cool.

For resilience, each room has pairs of air conditioning units that are fed from different chillers. There is enough capacity to keep the rooms cool even if we lost ½ of the air con infrastructure. We also run the fans from the UPS system to keep the air moving at all times, even during a power failure.

In addition to all this, we are cutting the fan speeds needed to pressurise the raised floor void by using baffles under the floor space to direct cold air where it is needed. We can vary the fan speeds and the input temperatures to precisely control the conditions within the cold aisles. We are making use of Thermal Imaging technology to map our data centre airflow and temperature distribution to ensure the best possible environment for your equipment.

All in all we are doing everything we can to reduce our energy costs and carbon emissions. This is something we can pass on to our customers and, when carbon taxes start to take hold it could add up to some quite significant savings.


It's Green Up North

Wednesday, December 3rd, 2008

By Rik WIlliams, Data Centre Operations Manager

How do you make a 3.5MVA N+1 data center Green, yet still cost effective?

That’s the big question that Node4 have been wrestling with over the last few months, but we reckon we’ve come up with the solution. Our brand new data centre (DC3) in Wakefield will be one of the first in the country to combine 2 of the latest energy saving technologies throughout the site: cold aisle containment and free cooling chillers.

By using these methods, we hope to make DC3 one of the most energy efficient data centres in Europe with a PUE of 1.3 to 1.4 (i.e. only about 1/3 of the total power to the site is used on cooling and power conversion).

Click for Cold Aisle Containment Diagram

Cold aisle containment is a new but relatively simple idea to get the best efficiency from air conditioning units. The data hall is set up as a standard hot / cold aisle arrangement but the cold aisles are then sealed off at either end and a transparent ceiling is installed to trap the cold air in front of the racks where it is needed the most. The rest of the room becomes a hot aisle as the air is returned to the air conditioning units, so the room itself will be between 30 and 35 degrees C.

Although that might be a bit warmer than the average techie is used to, the air flowing through the front of all the servers will be about 20 degrees C which is just as it should be.

This kind of arrangement gives a number of advantages over a non-contained room

  • Hot air can’t re-circulate and mix with the cold air. We are only cooling the air once
  • We can use a higher output air temperature from the air conditioning unit, saving on power
  • Temperature differences between the top and bottom of the racks are much smaller meaning that equipment at the top of the racks is less likely to fail

We estimate that this could save between 40% and 60% on our air conditioning bill, and will be far more environmentally friendly than a normal data centre.

We’ll talk more about how we actually cool the air using our new free cooling chillers and take advantage of the Yorkshire weather in a future blog post.


Archive



Search Wakefield Data Centre Blog Archived Posts