Air economizing describes the practice of using outside air to cool the inside of our data center. Traditionally, data centers were kept as basically clean rooms. Times have changed and current server equipment is more tolerable to humidity and temperature.

Red Rocks Data Center (RRDC) uses air economization to cool two of our server rooms. We’ll go over each of these and how different they are along with tremendous energy savings they have returned.

#1 – Main Colocation Room

In August of 2008, our 600 sqft colocation room was filling up rapidly and with only one 15 year old Liebert System 3 unit to handle the cooling, it was time for an upgrade allowing the Liebert to act as a backup. In Morrison, Colorado, rarely does the temperature rise above the 90 degree mark and with the addition of low humidity that we receive all year long makes our location a perfect choice for using air side economization.

At first, we decided to ‘build our own’. Add some duct work on the side of the building, build a fan enclosure along with a set of sensors to control the fans. Although this might have worked, it did not provide us redundancy in the hot summer days. We turned to Trane to provide the answer and they did with a Voyager 15ton unit that has a built in Economizer in it. When the temperature is below 72 degrees, it uses outside air as a ‘first stage’ to cool our colocation room. If it cannot keep it at 72 degrees, the 2nd stage kicks in which is traditional compressor cooling. Even when we’re at a 2nd stage of cooling, the unit is very energy efficient using 30Amps at 208v.

The end result? Since the final installation in November, 2008, we’ve saved on an average of $600 to $1100 a month in energy savings depending on the time of year. We’ve recorded no additional equipment loss (RRDC’s or customers) and no additional dust or outside fragments.

Some pictures of our setup can be found here. A construction blog was kept along with descriptions and photos which can be found here.

#2 – Dell Cluster Expansion Room

In January of 2009, a Geophysical company came to us asking if we could house their 128 node Dell cluster. According to Dell’s Capacity Planner, this would require over 13 tons of cooling. We had an area in our data center that we had yet to expand to but there was only 2, 15 year old SUN 3ton a/c units available in the room.

First, we knew that cooling outside air 100% of the time would be much easier than cooling 110+ degree server air. In addition, a majority of the time throughout the year, the temperature outside in Morrison, Colorado would allow 100% economization using outside air with no compressors.

We designed a heat containment wall that shuffled the hot server air and blew it outside via a large exhaust fan. We then installed new economizers in the SUN A/C units and set them to pull in outside.

The following diagram illustrates the end result in building a heat containment wall, installing an exhaust fan to blow the hot server air outside and layout of the racks. (click for a larger image)

The future of this room will look very similar. The concept of cooling only outside air in warmer weather has proven significant savings in addition to cooling with outside air when the temperature drops below 72 degrees.

The following diagram shows the future plans as we grow into this room: (click for a larger image)

The future is bright for air economization. Cooling a data center is 30-50% of the total energy costs and if these can be greatly reduced, data centers will save a tremendous amount of money.

We encourage tours of our data center to show these two projects and to answer any questions. In addition, please feel free to contact us if you have any questions or need additional information.