Part II: The Data Center Forest Has Gotten Greener

What’s new in data center energy efficiency today?

Seven years ago energy efficiency was not at the forefront of the data center world, but today, data centers are evolving to improve energy use. What is the bottom line? How is this helping our environment and are there potential savings for data center users?

Hot and Cold airstreams are separated via supply and return plenums. Today, Hot or Cold Aisle containment is beginning to appear in the most efficient installations. Our chilled water set points are warmer. We are comfortably running on the warmer-end of the ASHRAE TC9.9 ‘Recommended’ range for server intake temperatures. We install plate and frame heat exchangers for Free Cooling and we have better automation controls so we can actually use them.

Evaporative cooling units on the roof of T5@LA Data Center
Indirect evaporative units on roof of T5@LA.

We’re beginning to see evaporative cooling or heat wheels deployed in favorable climates, dropping those cooling kW loads even lower. We pump in ‘pre-conditioned’ outside air with small Dx AHUs so we don’t have to depend on our CRAHs (and colder chilled water set points) to maintain proper humidity levels. Those old 100kW “toasters” used for re-humidification are being replaced with ultrasonic units that need only 5kW (1/20th) of the power.

And that’s just the Mechanical side …

Electrically, we’re running fewer transformers on more efficient UPSs. We’ve worked around the harmonic distortion and leading Power Factor headaches of the past. Some designs even utilize higher voltages which helps reduce copper resources, while also slightly reducing feeder power losses.

On the I.T. side, we’ve stopped the single application per server madness and virtualized. Thanks to software management tools like VMware, our CPU annual average processing loads are now 70-80% utilized, rather than the 5-10% of the past. The server processors and power supplies are more efficient than ever. Even the internal cooling systems have been optimized with variable speed fans. Although we’ve been saying this for a long time, we may be at the cusp of liquid CPU cooling, which will make heat transfers several orders of magnitude more effective and re-energize Moore’s Law (which has effectively hit a “power wall” due to CPU heat dissipation limitations).

PUE was once a static calculation. It is now regularly presented in real-time on BMS systems.

Yep, just a few things have changed these past 5-7 years!

As an industry, we saw a potential vulnerability…power grid strains. We changed course and managed it without compromising availability. If there was in fact enough power and the threat was only imagined, we did something to greatly benefit our environment by reducing our global energy consumption footprint, thereby eliminating millions of tons of greenhouse gases.

But then again, we are data center operators. We’re smart and we solve problems. Through our collective knowledge and experiences, we did so in a big way! Not only do these innovations help the environment, but many help data centers customers’ budgets as well.

Stay tuned to our blog next week for Part III with a case study of energy efficiency and cost savings.

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