I just read an article in Engineered Systems magazine that reminded me of one of my own blog postings from a few months ago.  The difference is that the author in the ES magazine article went all mathematical on us and showed the formulas for calculating HVAC system reliability given the reliability of the individual components in the system.  Although it was a long time ago I remember going through the mathematical exercise in one of my engineering courses back at the University of Texas...so we have all known about this procedure for a very long time.

During this same week I have been asked to do a competitive analysis on a "new" system concept compared to one of our systems.  While I could name names that is not necessarily the important point of this posting.  What struck me about the competitor's "new" system concept was just how many parts were required to accomplish the task of providing "free cooling".  Many of those component parts had dependencies that meant that the proper reliability analysis was the "series" analysis.  You can refer to the latest issue of Engineered Systems if you don't remember what that means but in keeping with my simple approach to my postings the bottom line is that the reliability of a "series" of components is the compounded product of each item's reliability multiplied together.  In other words if the "new" system concept required 4 compressors that are staged in series, a direct drive exhaust fan array, a direct drive supply fan array, a sensible heat wheel motor, sensible heat wheel belt, sensible heat wheel bearings, digital control module, etc...and we gave each of those items a reliability of 98% (which sounds pretty good and is generous for some of the items in the chain)...then the "system" reliability would be:

.98 x .98 x .98 x .98 (compressor section) x .98 (exhaust fan) x .98 (supply fan) x .98 (sensible heat wheel motor) x .98 (sensible heat wheel belt) x .98 (sensible heat wheel bearings) x .98 (digital control module) = .817

So, the "new" system concept under this scenario would actually have a reliability of only 81.7%...not quite so good I think you would agree. 

The information from this example is actually directly from the competitor's product literature...and I left out some components for simplicity sake.  The reliability of the components at .98 was an estimate and you can plug in whatever numbers you think are accurate.  The important thing is to recognize that the more complex the system is the lower the reliability will be.

In a previous blog posting I quoted Albert Einstein who said ..."make everything as simple as possible, but not simpler.".  I still think Albert was a pretty smart guy and when I look at some of the design solutions being proposed today for data centers, pharmaceutical warehouses, or cooling in general I just have to wonder why we sometimes design such complex solutions.

Remember..."it is not sustainable if it is not maintainable"...and, as a corollary to that statement, "it is not maintainable if it is too complex and has too many parts"…

Many modern data centers are now being design to the latest ASHRAE TC 9.9 guidelines that allow the use of fresh air cooling for thousands of hours per year.  This obviously saves a tremendous amount of operating expense annually.  But a large data center requires thousands, if not tens of thousands, of outside air to provide the necessary fresh air cooling...so how does that air get into the building?

Aztec has been providing large outside air intake penthouses for data centers in the northwestern US.  These penthouses can approach 20 feet in length by 8 feet in width and 8 feet in height...no small structure!  Each penthouse must also be designed to prevent water from entering the data center so the Aztec units are designed with welded drain pans, sloped intake hoods, and carefully selected air intake velocities.  As an extra precaution against moisture intrusion the penthouses are also equipped with racks to accept "mist eliminator" type filters in addition to the MERV 8 or 11 standard filters that are installed in the penthouses.  As an added safety/security feature the penthouses also include a heavy gauge grate over the opening into the data center.  Access doors are provided for filter access and some versions include motorized dampers that can be programmed to respond to the outside air demands of the server farm.

Aztec is not the only Mestek company that is involved in providing air intake or exhaust penthouses for data centers.  The Arrow United division of Mestek is also providing penthouses of a slightly different design incorporating storm-resistant louvers.

Although the use of evaporative/adiabatic cooling in data centers is growing by leaps and bounds we face an interesting problem here at Aztec and Alton.  As part of a larger half-billion dollar corporation you would think that engineers and contractors would not be hesitant to use our products.  However, over the years our company has kept a low profile and that philosophy seems to be coming back to bite us.

The list of companies that are already using evaporative/adiabatic cooling includes some of the biggest names in the mission critical world....Facebook, Yahoo, Microsoft, Digital Realty Trust, Sabey, Google, Apple, Amazon, Skanska, CyrusOne, and  Dell...all use evaporative/adiabatic cooling in many of their centers.  Most of the time they are using either one-of-a-kind custom units from small specialty manufacturers with small support organizations, or, products from companies such as Munters.

In the class of equipment from larger evaporative cooling manufacturers Munters is probably the most widely known brand.  Most engineers, contractors, and mission critical decision makers are willing to accept the Munters name as a sign of quality due to their long history in the evaporative cooling world.  Munters started in 1955 in Sweden and has built a nice business that finally expanded to the US in the mid-1980s.

There is a company that pre-dates Munters by almost 10 years and has been in the US market for over 60 years...and that company is Alton and our indirect evaporative cooling brand Aztec.  Many of the techiques used by Munters and others in the evaporative cooling industry were either used or patented by Alton and Aztec long before these other companies even existed.  Many of those techniques were abandoned by Alton and Aztec because our experience in the field of evaporative cooling showed us that those techniques were either less effective or too costly to maintain for the user.

So when it comes to credibility and trust in this segment of the industry it seems there is another option that users should consider...Alton and Aztec.

It has been a while since I have posted anything to this blog...no, I was not on sabbatical on some desert island...I have been traveling around North America talking to consulting engineers, contractors, and data center owners and operators. This posting just provides a few insights that I garnered over the last 2 months on the road.

First, the data center/mission critical market continues to occupy the minds and the design resources of many, many companies in the design community. It is clear that this is a market segment that is vibrant and all indications are that it will continue to be for quite some time to come. The latest issue of Datacenter Dynamics FOCUS indicated that the world is now consuming over 300 Tkwh annually to drive data centers, with the US consuming over 25 Tkwh alone. The consumption in the US is projected to grow over 9% in 2013. While this information points to a growing market it also points to the urgent need for improved operating efficiency in data centers.

Second, and related to the first item, is the lack of knowledge about new "best practices" in data center design. I have talked to dozens of engineers, contractors, and data center people who are not aware of the latest design guidelines from ASHRAE. In fairness, those guidelines were only officially announced a few weeks ago...but they have been rumored and discussed for about a year now. I mentioned in one of my earlier posts that education of the design community is an important, and ongoing, task. This has been reinforced to me over the last 2 months.

Third, for those engineers and contractors who understand and embrace the new standards, is the challenge of convincing the data center people to adopt those standards. This is less of a problem at the top levels of the data center company than it is on the floor of the data center. The IT equipment operators who live in "the white space" seem not to understand the allowable operating temperatures of the equipment that they manage every day. I have heard many different reasons for their reluctance to adopt the new best practices but I think it comes down to fear. Because of stringent SLAs the operators worry about losing any equipment for any period of time...even though there is mounting research that this fear is unfounded.

Fourth, I have heard of several cases where the local electric utility has started to put limits on the available service capacity for planned centers. In the US we are so comfortable with the idea that our electric grid can provide unlimited power that we forget that is not true. We have a fixed number of powerplants with only so much generating capacity. With the tremendous growth of data centers, and data centers with 300 to 500 watt per square foot electrical demands, there is a limit to what a utility can do. And timing is another element of the equation. A data center can be built in a matter of months...a powerplant takes years. So even when a utility sees the demand coming they cannot add capacity as quickly as the demand can be added.

So, these are a few observations from the last couple of months. Of course there is more to the story and feel free to comment on this post with any questions you might have. I will try to respond as quickly as possible.

The attached article from Processor Magazine provides a very good description of the benefits of the Aztec ASC indirect evaporative cooling products for the small to medium sized data center.  The key product feature that can save smaller owner/operators lots of capital and operating costs is the built-in DDC control system in the Aztec unit.  The Aztec DDC provides most of the same functionality as a third party DCIM but without the extra cost and coordination that comes from putting an information/control overlay on top of the data center cooling equipment.

Well, this is embarrasing. I have been in the HVAC industry for over 40 years now and have helped design and manufacture some of the more sophisticated products that have been introduced. But, in spite of that I have to admit that I messed up. And the lesson that I was reminded of can help you too if your residential, commercial, or mission critical system is struggling to keep up with the heat.

Over the past couple of weeks the temperature here in Texas has been over 100 degrees F every day...sometimes up around 105 to 110. That is nothing unusual for Texas in the summer and not as bad as last year. But I started to notice that my residential HVAC unit was no longer able to maintain my thermostat setpoint of 77 to 79 degrees F. The system was consistently running 3 degrees behind and running non-stop...and was only installed a year ago.

Refrigerant leak? Undersized? Dog left the door open?

No...it was one of the most common problems in any HVAC system that is not running correctly...the condenser coil was coated with a fine film of dirt. Let me repeat that...a FINE film of dirt. Not clogged...not even very obvious at a quick glance...a FINE film. In my case it was actually a fine film of dryer lint since the clothes dryer outlet was located behind the condensing unit...but the point is that had a service tech not looked at the coil with a flashlight I never would have noticed the dirt. Running water over the coil from a garden house to wash off the film dropped the system head pressure and restored the system's ability to maintain the thermostat setpoint without running non-stop.

Many years ago Louisiana State University conducted some tests on residential HVAC systems to determine the impact of dirty condensing coils. The results were eye-opening. A fine film of dirt, similar to what I had on my system, would reduce system capacity by up to 20%. If your home, business, or server room is too hot then imagine what giving it an extra 20% of capacity could do...and it would only cost you a bit of water and time to wash off the coils...with no service tech assistance required.

I have had a busy few weeks traveling to meetings and visiting with owners, operators, engineers, and researchers. This has given me an interesting perspective and awareness of an issue that our industry needs to address. My awareness of this issue was increased by an editorial in Mission Critical Magazine that bemoaned the lack of progress in data center design due to secrecy regarding "best practices".

I came away from all of those meetings with the sense that there are many very smart people who know how to design more efficient solutions to energy use in mission critical applications. "Best practices" can be described by experts from the largest server manufacturers, global data center developers/operators, and from academia. The issue is that we are all sitting around a large table in a closed meeting room and sharing that knowledge with others who already have a pretty good idea what to do. We are "preaching to the choir".

The result is that the vast majority of data centers, server rooms, and telecom facilities are operating in very inefficient ways. While a Microsoft might be able to design a data center with a 1.2 PUE the rest of the world is struggling to reach a 2.0.

This came out in a technical committee meeting at ASHRAE's mid-year meeting a few days ago. A comment was made by a server cooling system manufacturer that he finds it very difficult to convince smaller users to adopt the latest operating standards that could save the user tens of thousand of dollars a year in energy costs. This sentiment was echoed by several around the room and pointed to how difficult it has been to educate the broader public on the reliability of modern equipment in warmer rooms.

And when I say "broader public" I mean just that. The mechanical design director for a global retail data center operator told me that he knows his equipment will run just fine at 78 or 80 degree F inlet temperatures but his customers have not gotten the message and demand a "cold" room. It seems that until corporate IT managers and executives understand all of this we will continue to see skyrocketing energy use by data centers. Even small server rooms could benefit from elevated temperatures if key elements of "best practices" were implemented. So called "legacy" data centers might be difficult to retrofit but they can certainly be upgraded with the basic elements of "best practices"...if only the occupants understood what is possible.

The industry has a massive educational challenge if it is to stem the rising cost and consumption of energy. And the education cannot come soon enough because the projections are that server power densities will continue to climb and data storage power densities will climb even faster. Today we talk about 300 watt per square foot densities but systems are being designed already that push almost 10 times that density. It may seem that we have an endless supply of power from the grid but there are only so many power plants around the world and building a new one takes a decade or longer...data power consumption grows at a much faster rate and will stress grids around the world eventually if we cannot educate the "broader public" more effectively.

Richard Kirkland, Sales Manager for Business Development, at Mestex exhibited a display version of the Aztec indirect evaporative cooling system at the recent Texas Air Systems sponsored golf tournament for the DFW ASHRAE chapters.

The unit on display was the smallest of the Aztec indirect evaporative cooling line and included the features most in demand for the data center and server room market.  DDC controls, VFD supply and cooling tower fans, direct drive plenum supply fan on vibration isolation, and fire resistant fiberglass cooling tower media were all part of the display unit.

On April 12, 2012 management and engineering representatives of Aztec, part of Mestex division of Mestek family of products, met with engineering representatives from the University of Texas at Arlington to define how resources will be jointly applied to researching and developing an advanced technology indirect evaporative cooling solution for data centers.  Research already started at both organizations will be shared in order to more quickly advance the development of a viable solution to the high rate of energy and water consumption by data centers.

The joint project will be part of the NSF-I/UCRC program.  This program, initiated by the National Science Foundation, is a collaboration between 5 major universities and a select group of industry contributors.  The stated purpose of the program is to develop commercially viable solutions that will improve energy efficiency in data centers.  Research projects range from chip level solutions all the way to complete, large scale, data center solutions.  Aztec will be contributing special knowledge of evaporative cooling and outside air cooling solutions that has been developed over 40 years of product development and marketing.