All posts by alanlachapelle

Uptime Institute Network Conferance

This week I had the pleasure of presenting at the Uptime Institutes Group 3 and 5 network Conferance with my colleague John Gray. First, let me thank the Uptime Institute for the opportunity and also the terrific audience. We received terrific feedback and engaged in some really great discussions. I would also like to thank the other presenters for their fantastic presentations, especially the team from Thompson Reuters who presented on two fantastic topics and the Fidelity team for hosting and providing great input to the group. What a week!

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Is airline travel too safe?

I just read an interesting article providing a nice contrarian perspective on airline¬†travel domestic and abroad. It compares the cost of a life saved relative to money spent in other areas. Keep in mind, I’m writing this at the airport so I am painfully considering the implications of the points I am making. While this may seem ludicrous at first, the idea of making something less safe, I realized that this might help me make an interesting point effectively, one that I struggle to articulate. The article points out how more effective spending on vaccines, safety belts in cars, and other areas of our lives relate to the money spent on aviation safety. Because of very effective FAA regulations, poor countries spend a lot of money on aviation safety while school children are unvaccinated and traffic deaths occur at significantly higher rates.

So what point, relating to data centers, could I be getting at? Are we spending money in the most effective manner to realize high availability. Much like the net loss of life in poor countries would be lower if they allocated resources where they have the most impact, so too we can improve our loss of compute by investing where impacts are highest.

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Chill water resets

Do you have a chiller plant? Is your air handling equipment operating at some level below 100%? You can probably benefit greatly from a chill water reset, especially if you operate with a largely sensible load (like a data center!). Even if you have latent cooling, the latent capacity is not impacted as much as you think by higher chill water temperatures. The coils leaving air temperature is what determines how well the air handler removes humidity as that air is typically at saturation. So as long as you are meeting your air temperatures set point, latent capacity is not impacted.

So what of the chill water reset? Well, ASHRAE recommends, in a series of articles co- authored with Taylor Engineering, the use of a chill water temperature reset followed by a chill water d/p reset.
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NPV Calculator

For all those looking for some easy peasy NPV calculations I put together a spreadsheet. Please note, I am always open to improvement so if you see something that can make it better please let me know.

Just fill in the yellow boxes (I have locked down discount rate at 10% and inflation at 3%, if you know enough to want to play with that let me know and I will give you the unlock password).  Select 10 or 15 year project life, and the spreadsheet will auto manipulate. This is focused around energy savings projects but you can use anything with a cash flow that will accelerate with inflation.

NPV calculator simplified

Spring is coming

Spring is coming. Will your data center be a spring chicken or an old bird? As the weather begins to warm (hopefully) this is a great opportunity to take stock of your data center and it’s economizer system and operation.

We have this sensor, we call it the million dollar sensor. Now how can a single sensor be worth a million dollars? The answer is simple, really, it’s the outside air temperature and humidity sensor, and we have selected it such that many of the problems with other sensors, particularly humidity, are eliminated. By having a highly accurate sensor, we can reduce the margins for the economizer to engage ( for instance, return air temperature plus 2 degrees instead of 4) and have knowledge that we won’t be what I call “anti-economizing” where the air we bring in has more enthalpy than the air exiting the building.

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ROI – a misunderstood metric

Right now there’s a phone commercial. A guy is building a birdhouse and he says to someone else “I’m thinking of renting it out to get a better return on investment”. Now this guy understands what ROI is. He has an investment. He understands what it means. It’s how much he makes relative to what he put into it.

Investopedia defines ROI as the amount of net income returned as a percentage of shareholder equity. It further amplifies this definition to allow for different organizations to calculate ROI differently. ROI can be a cash amount, it can be a ratio, a percentage, or an annual yield. One thing clearly absent from this list of possible ways to calculate a return on investment is a time period.

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Maximizing Utilization by Revisiting SLAs

First, let me define SLA as it relates to this discussion. SLA is service level agreement and for the facility minded individual is how we guarantee conditions at the server. We guarantee uptime and with properly corded devices we guarantee customers will not lose power. We also have temperature and humidity SLAs. They might be do not exceed 60-89 degrees f and 20-80% relative humidity for more than 4 hrs, for example. Now we have a target band tighter than that but that is our promise.

With that understood, we can start the discussion. Let’s say we have 2 MW busses with 4 primary and 1 redundant bus using static transfer switches to transfer to the reserve (redundant) bus. Let’s say that each bus has 1400 kW of UPS power, requires 100 kW for house loads, 100 kW for UPS losses, 40 KW for lighting, and 760 kW reserved for design day cooling. As we can see we will not be able to use about 400 kW of installed UPS capacity. Continue reading Maximizing Utilization by Revisiting SLAs

House loads / PUE

Right now we’re having a bit of a debate on how to calculate PUE. We are all familiar with the GreenGrid definitions of PUE 1, 2, 3 etc but our debate is which is most valid. As a colocation provider we lease data center space. We also lease data center adjacent office space. Should this space count against our PUE? Some of our sites don’t have offices while some do. Comparing them to identify opportunities would require a similar metric wouldn’t it? The office really isn’t supporting the center, it’s its own entity. At the same time, we have been including office, so the historical readings will no longer be as relevant if we change PUE. I’d like to open up a discussion here if anyone is interested.

I’m not as obsessed with conforming to an industry standard as I am with providing useful standards for comparison and progress. Of course us in the know are looking at so much more than just PUE, we break down the load path, find out where our power is and where it should be, and look for opportunities or solve issues. Yet PUE is an important tool for executive level reporting.

Metrics for goals – PUE, kWh, or $$

What’s the best measurement of success in an organization when your talking about energy savings? Cash savings is great because it’s quantified in the most important business metric. Unfortunately it does not correct for changes in IT load and utility pricing. kWh gets at what is most controllable by efforts of the group trying to save energy, but again needs to be calibrated for IT loads. If we benchmark against expected energy spend (vice previous spend or trended spend) then we can use the actual IT load and the results can represent what the energy efforts actually accomplished. PUE doesn’t need any calibration, but it isn’t quantified. The statement PUE went from 1.77 to 1.65 is meaningless to a income statement. And those are the results with impact ( save $400,000 a year with a net present value of $2,500,000 and a first cost of $300,000 for improvement is a great victory to anyone in corporate finance). It’s a juggling act, maybe it depends more on who is seeing it. But when your getting evaluated for year end performance, which is most important?