I’ve been involved in the design and development of over $6 billion of data centers, maybe about $10 billion now, I lost count after $5 billion a few years ago, so I’ve seen a few things. One thing I do see in the data center industry is more or less, the same design over and over again. Yes, we push the envelope as an industry, yes, we do design some pretty cool stuff but rarely do we sit down with our client, the end-user, and ask them what they really need. They often tell us a certain Tier level, or availability they want, and the MWs of IT load to support, but what do they really need? Often everyone in the design charrette assumes what a data center should look like without really diving deep into what is important.
When we do that, we can get some very interesting results. For example, I’ve been fortunate to have been involved with the design of three data centers this year and all three we were able to push the envelope of design and ask some of these difficult questions. Rarely did I get the answers from the end-users I wanted to hear, where they really questioned the traditional thinking and what a data center should be and why, but we did get to some unconventional conclusions about what they needed instead of automatically assuming what they needed or wanted. As a consequence, we designed three data centers with low PUEs, or even what I like to call “ultra-low PUEs“, those below 1.10. The first was at 1.08, the next at 1.06 and now we have a 1.046, OK, let’s call it 1.05 since the other two are rounded up as well. (We know we can get that one down to about 1.04 with a few more tweaks to that “what is really needed” question.)
Now, I figured that a PUE of 1.05 was going to take a few years to get to because the hardware needed to improve, i.e. chillers, UPS, transformers, etc. But what I didn’t take into account was that when we really look at what the client needs, not wants, and what we can do to design for efficiency without jumping to the same old way of designing a data center, we can reach some great results. I assume that this principal can apply to almost anything in life.
Now, you ask, how did we get to a PUE of 1.05? Let me hopefully answer a few of your questions: 1) yes, based on annual hourly site weather data; 2) all three have densities of 400-500 watts/sf; 3) all three are roughly Tier III to Tier III+, so all have roughly N+1 (I explain a little more below); 4) all three are in climates that exceed 90F in summer; 5) none use a body of water to transfer heat (i.e. lake, river, etc); 6) all are roughly 10 MWs of IT load, so pretty normal size; 7) all operate within TC9.9 recommended ranges except for a few hours a year within the allowable range; and most importantly, 8) all have construction budgets equal to or LESS than standard data center construction. Oh, and one more thing: even though each of these sites have some renewable energy generation, this is not counted in the PUE to reduce it; I don’t believe that is in the spirit of the metric.
Now, for some of the juicy details (email or call me for more or read future blog posts). We questioned what they thought a data center should be: how much redundancy did they really need? Could we exceed ASHRAE TC9.9 recommended or even allowable ranges? Did all the IT load really NEED to be on UPS? Was N+1 really needed during the few peak hours a year or could we get by with just N during those few peak hours each year and N+1 the rest of the year?, etc. The main point of this blog post is to say that low PUEs, like that of 1.05, can be achieved, yes, been there and done that now, for the same cost or LESS than a standard design, and done TODAY, saving millions of dollars per year in energy, millions of tons of CO2, millions of dollars of capital cost up front, less maintenance, etc. We just need to really dive deep as to what we need, not what we want or think we need, and we’ll be better at achieving great things. Now, I need to apply this concept to other parts of my life; how about you?