April 2004

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Getting Honest About Comfort

Thomas Hartman, P E
The Hartman Company

Comfort and environmental quality complaints top nearly every survey made of building occupants' concerns about their workspaces. 

This U.S. election year has started off with a bang about who's telling the truth and who isn't. In the HVAC industry we have also have a serious a problem with honesty when it comes to comfort. And now is an excellent time for us to come to grips with it because we're seeing new approaches that could help us enormously. First, let's define the problem.

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Imagine your company has just relocated its offices to a brand new building. A property manager for the building is showing you your new office and explaining to you that this building employs the very latest technologies to make your workday as enjoyable and productive as possible. Such discussions take place all the time.

So, you think about what you don't like about your current office. If you're like most people that have been surveyed, one of the first things that comes to your mind is the fact that for one reason or another you are not very comfortable in your present office, but as you look around this new office, you don't see any temperature sensor or thermostat. So, you ask about it. "Well…,' it is explained, 'there actually isn't a temperature sensor in this particular office. The temperature control for this zone is accomplished from a sensor in another office, one or two doors away." "But', the property manager adds with great confidence, "the system has been carefully designed and engineered so when that office is comfortable, yours will be too!"

Would you believe that? I don't think many of us would. It is, frankly speaking, a lie, one that engineers, contractors, building owners and property managers employ daily in their work without even thinking about it because such terminal unit configuration and layout is part of what we call "industry practice." And to be sure, included in this industry practice are also design methodologies that attempt to mitigate the effects of a single temperature sensor controlling multiple offices by balancing as best we can the heat loads and air flows among the various spaces served by each terminal zone. But as the variations in heat loads have grown from office to office, and as variations have become far more difficult to predict ahead of time, the concept of a carefully engineered system capable of keeping multiple spaces comfortable with a single point of temperature reference is no longer a reasonable premise in a modern office building. As a result, comfort and environmental quality complaints top nearly every survey made of building occupants' concerns about their workspaces. Furthermore, advancements in technologies are such that this unhappy situation need not be so prevalent, since there are an enormous variety of comfort enhancing technologies that are being developed and could be brought in to vastly improve comfort and air quality in office buildings.

So why aren't we doing anything dramatic to make the ultimate users of our designs happy? Engineers often talk about tight budgets. They explain that they don't have the flexibility to do what it takes to improve building comfort. But my analysis shows this to be more an excuse than the real reason. Rather, the root problem appears more centered in our industry than our clients. End users have pretty consistently been telling us over the years that we are not doing our job well and building management has been clear that it regards comfort as a very important feature in their buildings. However, rather than listen, the trend is for our industry to increasingly turn a deaf ear to these concerns. In my observations, discussions about comfort at professional gatherings have decreased over the last decade. Instead, it seems engineers have tended to join with building operators in blaming building occupants as natural complainers who will never be satisfied in so far as comfort is concerned - an almost textbook example of blaming the victim. Very seldom do we find engineers nowadays even discussing or proposing the incorporation of comfort enhancing technologies into their projects. Instead, the issue of comfort has been largely ignored as the industry focus has changed over the years such that engineers now spend most of their time on comfort system infrastructure issues rather than on the issue of comfort itself. For some buildings the entire discussion between engineer and client on comfort amounts to the engineer recommending a particular space air temperature setpoint for the building.

If we keep in mind that the sole purpose of all the HVAC equipment designed and installed in a building is to provide comfort and environmental quality for building occupants, and that complaints about these features far outweigh all others in nearly every building occupant survey, it seems logical we should think about refocusing our design time and project budget away from infrastructure issues and direct it more on zone level improvements aimed at achieving better end results. We need to spend less time and money on exactly which chiller, or boiler, or fan, or control system to employ and more on how we can keep people comfortable considering the range of occupancy, internal heat loads, and outside weather conditions we can expect. To the greatest extent possible, the decisions on the infrastructure to be employed should be secondary, driven by what we find concerning how the building environment can be made more comfortable and of higher quality over the entire range of anticipated conditions.

To reorganize ourselves in this manner means that we must find a way to do this and still turn over a mechanical system that is of high quality, efficient and reliable in the long term without increasing the design and construction costs. But the answer to this question has also been developing over the years. Manufacturers, contractors, and others in the industry are becoming more proactive in providing entire systems that employ their products or services. They have developed specialized design tools that at present often duplicate elements of the engineer's design effort. For example, a designer may provide a full layout of a heating and chilled water piping system at some considerable expense, only to see the installing contractor independently develop and propose his or her own three dimensional solution that has much greater detail and may also be more efficient in the use of pipe and connections. Piping layouts completed by designers are therefore diminishing in value to projects. In many projects, engineers really need only to develop certain equipment layouts to the extent that it can be assured the space is adequate for the equipment and piping required. Then, with a good system schematic and operating criteria, the installing contractor has all that is required to develop and submit for approval and ultimately the as-built record, a very detailed set of layout drawings that will also allow the installation effort to be more efficient. The submitted design is very likely to be more efficient and cost effective from an operations standpoint than can be developed by the engineer, in part because contractors often have design tools and resources that may be more effective than those of the engineer. Similarly, many equipment manufacturers have powerful tools to optimize the layout and selection of their equipment in order to maximize the access for maintenance while minimizing the footprint requirements.

Engineers can tie into this available expertise and save both design and project dollars. Imagine specifying and selecting a chilled water plant without first preparing detailed equipment selections and layouts of towers, chillers, pumps and piping, but instead, requiring the plant to provide a certain capacity, fit into the available space and be integrated into the building control system with a guaranteed level of performance (average annual kW/ton) and a long term warranty/service agreement. There are an increasing number in this industry that are literally waiting in the wings, ready to respond to such requests, and the process to develop a simple and well constructed RFP and choose the best proposal takes far less time for the designer. Generally, comfort system designers can expect a plant so designed and constructed to cost less, require a smaller space, and perform far better than one they would design entirely themselves. And it frees them up to focus on the real purpose of their work.

Standing back from the mechanical system infrastructure and focusing on the real purpose of HVAC systems is not likely to be popular or easy for many engineers. Comfort system design engineers rightfully take pride in their detailed knowledge of chillers, boilers, fan systems, as well as piping and ductwork. But this is not, and should not be, the true focus of our design efforts. Rather our industry needs to retrain itself to better focus on our purpose - occupant comfort and air quality. And then too, we need to be more honest with the end users and with ourselves about how well we are doing, and how well we can do if we really work at delivering comfort and environmental quality in our designs.

For those interested in getting a better understanding of new technologies that can improve comfort and energy efficiency together, consider attending the Intelligent Building Technologies Summit on May 4th in which Mr. Hartman will participate. This conference is in San Diego and is sponsored by the San Diego Regional Energy Office. To get more information visit: 

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