March 2004

Innovations in Comfort, Efficiency, and Safety Solutions.

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Perfect We Ain't  But Becoming Better is Surprisingly Easy

Thomas Hartman, P E
The Hartman Company

New and emerging technologies could be applied so much more effectively than they are. And I found that increasing numbers in our industry are looking for new approaches so that they can do what they do much better.

On the way to the ASHRAE Winter Meeting this year I read David Well's book on his experiences in baseball. Baseball and the HVAC industry don't have much in common, but one thing rings true, neither attains perfection! For me, my work is a source of great enjoyment, particularly in this time of great technological change. I am thankful that I have the opportunity to work with many fine engineers, contractors, manufacturers and owners to develop new applications for wider use in improving building performance and operating efficiency. I returned home from this winter's meeting reenergized and brimming with enthusiasm to work toward narrowing the gap between where we are and where a slightly more perfect industry would bring us!

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The ASHRAE Winter meeting and AHR Expo was a very positive experience for me in this regard. I talked with engineers, manufacturers and others who understand that the design, equipment selection, and procurement decisions each of us make in this industry could be much better. New and emerging technologies could be applied so much more effectively than they are. And I found that increasing numbers in our industry are looking for new approaches so that they can do what they do much better.

One individual with whom I talked during the meeting was a control contractor whose approach and story I particularly enjoyed. He was lured into the field by his prospective employer's business - "Comfort Control Contractor". Having dwelled much of his adult life in uncomfortable buildings, he looked forward to participating in a business that could do something about it. When he found this business actually had almost nothing to do with comfort, he made it one of his career objectives to change that sad fact.

Rather than focus on all the details in the control specifications that came across his desk, he decided to look at how the controls he was bidding on could really keep people comfortable, since that was the ultimate purpose of the system being controlled. His field work led him almost immediately to the discovery that a major reason buildings are so uncomfortable is the temperature in most building spaces is often outside of recognized comfort limits! Few spaces in buildings are even monitored for temperature, and the location of sensors in those that are is not well thought out. Equally shocking was the seeming ambivalence by many of his seasoned colleagues to this finding.

His next finding was just as shocking to him (and uninteresting to his more experienced colleagues) - that the use of a fixed supply air temperature so typical in many VAV systems is absolutely incompatible with maintaining comfortable conditions in office buildings throughout the changing seasons and conditions.

He took these revelations to his management who yawned and politely told him to think about how he these findings and his resulting ideas for improving the comfort in buildings might be used to generate additional business. The ensuing years brought further revelations, a great deal of frustration, but also enough success to keep his employer satisfied and him focused on comfort. I really enjoyed his perspectives on how poorly the industry operates to meet its purpose and how steps the industry has taken to help the situation have not. For example, he characterized commissioning as a process that too often "gets the wrong things right!"

He found that ongoing support is the key to success in higher performing buildings. He talked his firm into offering on-line support services. It's been very successful and his firm has many very pleased clients.

In presentations I made during the meetings and expo, I tried to focus on the implementation of incremental improvements that involve more advanced technologies. As the control contractor with whom I spoke observed, most experienced engineers and building operators know that keeping the supply air temperature fixed in VAV systems does result in poor comfort and/or air quality in cool or cold weather, but very little is done to accommodate an effective approach toward integrating a changing supply air temperature into an overall HVAC system design. Rather, it is too often left to the building operator to manually adjust the supply air temperature setpoint in cold weather and find some compromise between the increased air movement and the reduction in zone cooling capacity. In one presentation I encouraged engineers to look at effectively integrating a changing supply air temperature strategy into zone control in order to improve comfort, lower the overall system cost and improve system efficiency. In the long term, changing from outdated fixed temperature and pressure setpoints throughout HVAC systems to optimized operations will greatly improve building comfort and can cut their energy use in half. But like baseball with all its traditions, there is simply too much built-in resistance to expect that all the changes necessary for this to occur will happen overnight.

Instead, as the contractor with whom I spoke has done, I recommend to designers, contractors, and manufacturers an incremental approach whereby we all shift our focus to the ultimate purpose of our activities - efficient comfort - and, keeping that focus, start a transition from the older technologies we continue to employ to the newer, more effective and efficient technologies that are now possible with improved integrated controls and other advanced equipment; moving ahead one step at a time.

But it may be a long road if we don't work together effectively. This was made clear to me by other discussions I had during the ASHRAE/AHR meetings. For years I have been working to convince engineers in the industry that continuing to design and operate variable speed systems as we have their constant speed predecessors is not effective. By moving away from outdated proportional methods of control (now commonly referred to as "PID" control), we open ourselves up to the prospect of much more efficient methods of variable speed equipment control and huge reductions in valve and damper pressure losses that occur in distribution systems today. These technologies have the capacity for reducing the energy use of these systems to a small fraction of what they now require.

But there is enormous resistance to such changes, and I heard much of this during and the meetings and expo. I was again reminded of the adage that for those who have come to rely on one level of technology, stepping up to a new level seems to be equivalent to embracing witchcraft - it seems so counterintuitive or even "unnatural" compared to what we have come to accept as they way things naturally work.

In several different conversations, I listened to engineers tell me that variable speed will cause some systems to use more energy and that throttling valves or dampers across a substantial pressure gradient is an essential ingredient of good control practice. Moreover, I was told that alternative methods of control I know to be theoretically sound and have applied with success will not work in particular cases because of this reason or that.

Some of this comes from inexperienced individuals who don't fully understand the issues they are rendering an opinion upon. However, a surprising amount comes from experienced engineers who are respected in the industry and should know better. Of course not every point made should be completely dismissed either. We all need to recognize the fact is there is no perfectly straight and smooth road to the future. And none of us has a compass that shows the exact direction our industry needs to take. Our job throughout this period of transition is to understand that teamwork is what is required to develop effective systems that incorporate newer more effective and more efficient technologies. If we can develop the tools to work together effectively in order to support the design, procurement, implementation and operations of newer technology systems, not only will we provide far better building comfort with far better operating efficiencies, but we will have a model of successful teamwork that is from my reading well ahead of the levels of cooperation being achieved in the ultimate team activity - baseball!

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