HVAC building-controls expert Tom Hartman on the design engineer's role, achieveing success in a dysfunctional environment, creating building efficiency plans, and achieving better building performance.
Editor’s note: Tom Hartman, PE, principal of The Hartman Co., Georgetown, Texas, has been a regular contributor to HPAC Engineering’s Networked Controls Plus newsletter since its inception in June 2011, lending his respected and provocative voice to many issues that confront the building-controls business. Here is a compilation of excerpts from Hartman’s editorials that have appeared in Networked Controls Plus over the past year. To subscribe to Networked Controls Plus, visit http://bit.ly/NCPsubscribe. Hartman can be reached at 254-793-0120 or by e-mail at firstname.lastname@example.org.
From ‘Building-Controls Designers: Conducting the Orchestra,’ December 2012
I often envision the 21st-century building-controls designer acting like the conductor of an orchestra. A conductor needs extensive experience as a musician and a member of an orchestra to develop a good sense of what is required to have an orchestra perform well. Similarly, consulting engineering firms need to recruit controls designers who have extensive backgrounds of hands-on controls experience and understand what is required for a controls system to perform well.
But the transition to designer—like that to a conductor—requires a huge change in one’s perceived role. The famous conductor Andre Previn used to lament humorously that he had to give up music to become a conductor. In that same context, a controls designer must understand that developing effective controls systems requires him or her to “conduct” the process from start to finish, rather than participate directly in it.
Here are the crucial steps in the process of achieving high-performance building controls:
Step 1: Develop specific design and performance goals. Controls designers must start by authoring a detailed description of a proposed system and operation (design intent) and conduct a rigorous analysis to determine specific comfort and energy-performance goals. The design and performance intent should detail how the goals will be achieved.
Step 2: Assemble the right players who will achieve the performance goals. Different control systems and contractors have widely varied capabilities, and it is essential that bid or request-for-proposal documents limit products and services to those the designer knows can achieve what is required for the project.
Step 3: Establish accountability paths to ensure performance goals are met and maintained over time. Engineers need to develop standards to ensure controls contractors, commissioning agents, and operators or operations-support firms are aligned and accountable to meet performance goals. Engineers need to integrate performance criteria into their contract documents, along with flexibility to add accountability for their performance goals.
Step 4: Stay with the process to ensure it succeeds. Performance goals often are compromised in the processes of resolving the myriad details of construction. But if the engineer has developed and maintains a strong focus on performance accountability among those on the contracting side, it is far less likely that performance will be compromised because those resolving the details come to understand that allowing such compromise will adversely affect their contracts.
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From ‘Achieving Success in a Dysfunctional Building-Controls Environment,’ March 2013
I have stressed the need for design engineers to become more involved in implementation of the control systems they specify. But in today’s fragmented building construction process, it still is almost always left up to the controls contractor to make it all work, regardless of the array of points and sequences that have been specified.
If you are a controls contractor, here are five steps you can and should consider to improve the performance of your building-control-system projects despite the potential problems and hurdles you will likely encounter throughout the implementation process.
Step 1: Assess the controls design. How to most efficiently prosecute a controls project has a lot to do with the quality of the design provided in the contract documents. The place to start looking for design quality is the sequence of operations, to see how clearly the operation of the various systems is described.
Step 2: Assess the design engineer. Regardless of the quality of the design, some engineers can and should be more involved in the controls implementation than others. Trying to work with an uninterested (or unknowledgeable) engineer can be problematic.
Step 3: Communicate. Issue clear, concise, and comprehensive requests for information. Regardless of the decisions made in the previous steps, maintaining communication with the engineer is essential.
Step 4: Program using standard software modules wherever possible. Your company should develop or acquire standardized software modules for the many HVAC systems typically operated by building controls and should work to ensure standardized software modules are applied whenever possible.
Step 5: During commissioning and startup, resolve problems rather than point fingers. It is very frustrating to have followed a sequence that you know won’t work and then to be blamed when it doesn’t. However, simply proceeding down such a path will likely be costly to you both financially and in goodwill. Be sure you head off such situations as early as possible with proactive response.
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From ‘The Wave of the Future: Building-Efficiency Business Plans,’ June 2013
One of the most soft-pedaled of policies from the U.S. Department of Energy (DOE) is that of reducing building energy use in the United States by 50 percent below 2004 levels by 2030. That is a very ambitious goal, but it’s do-able because it really just requires cleaning up the waste in building energy use.
Building owners already are reluctant to invest in energy-efficiency improvements. The simple reason is that the performance drift for typical buildings is of such magnitude that many such retrofits lose nearly all their savings benefits after just a few years. So just reducing the first cost of energy retrofits is not likely to energize building owners, and it most certainly will not achieve the policy goal.
What is needed is a system of building-performance targets, along with periodic indicators to tell building owners how their buildings are performing. The ENERGY STAR rating program is a reasonable start. Take the kBtu-per-square-foot result from the ENERGY STAR rating (instead of the rather meaningless comparison rating) and compare that number with the 2004 Commercial Building Energy Consumption Survey average for that building type and climate. This makes it easy for the building owner to see how much energy-use reduction is needed to meet the 2030 target.
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From ‘Getting Past the Building-Performance Brick Wall,’ September 2013
There are three elements to effective building control. The first is control that effectively coordinates all the components of each system and then all the systems together to generate and distribute heating, cooling, airflow, and lighting as efficiently as possible. The second is control that effectively distributes these resources to where the needs are in the building. The third is control that continually evaluates system operation and alerts operations and maintenance support and automatically compensates system operation when a component or system is not performing as it should.
Each of these fundamental elements is sadly lacking in building control systems as they are designed, implemented, and operated today. Currently, control software is conceptualized for buildings by engineering teams that often have no experience with modern controls. These teams incorporate outdated concepts that restrict the ability of system components to operate to achieve overall efficient operation. The engineer’s concept document, known as the “sequence of operations,” then is handed to the contractor’s selected controls subcontractor, who, independent of the engineer, integrates those crude sequences into a software operations scheme. That software then is massaged during startup and commissioning until a workable status is achieved. At that time, it is all turned over to an operations staff whose only support, if any, comes from the implementer.
The result of this disconnected process is the crude building controls we see operating in buildings today. The problem is that no one in this loose chain of events can do anything to change the outdated process because no one has authority or control over—not to mention the understanding of—all the other stages of the process. So the process has remained unchanged for decades as its potential to improve building performance has grown enormously.
For the full article, visit http://bit.ly/Hartman5