In the News
Best Practices for Designing Government Buildings
A Conversation with the Editors of Consulting-Specifying Engineer Magazine - July 2020
Mueller Vice President Todd Garing, PE, LEED AP, recently participated in an industry roundtable on current trends and best practices in government facility design. His responses and insights are summarized below. Click here for the complete roundtable article.
Q: Each type of project presents unique challenges — what types of challenges do you encounter for these types of projects that you might not face on “civilian” or other types of structures?
A: Most of our project types present unique challenges. For example, some government buildings also serve as public and performing arts spaces, requiring large cooling loads and strict acoustical requirements to account for vibration, air velocities and distribution restrictions.
Government buildings may also have museum spaces, which require strict temperature and humidity conditions to preserve collections. In doing so, achieving energy efficiency also requires being very creative and having a thorough understanding of fundamental engineering.
Government buildings that include laboratories have varied needs, such as occupant safety and inconsistent use of equipment that presents challenges for systems to be responsive to changing demands and able to turn down when not needed to save energy.
Many government buildings are also historic structures, which present major challenges when tasked to incorporate modern systems, minimize energy consumption, maximize sustainability and not impact the building’s historic fabric.
Overall, many institutional owners are always highly interested in sustainability but are frequently challenged by budget constraints. In these circumstances, we discuss various options and offer examples of past projects and perform life cycle cost analyses to help inform their decision-making process.
Q: What are engineers doing to ensure such projects (both new and existing structures) meet challenges associated with emerging technologies?
A: Designing systems with an eye on the future is a core principle and we design systems to be compatible with this philosophy.
One example is using low-temperature heating water, which may not be required if, for instance, the building is connected to a central steam plant, but the low-temperature water is compatible with efficient systems such as heat recovery chillers, water source heat pumps, geothermal, solar thermal and condensing boilers. We also try to minimize roof-mounted equipment and provide electrical pathways to maximize photovoltaic arrays, even if they are not included in the initial scope of the project, but are available for the future.
Q: Tell us about a recent project you’ve worked on that’s innovative, large-scale or otherwise noteworthy.
Q The Smithsonian National Air and Space Museum on the Washington, D.C., National Mall is undergoing a full-scale renovation. At the beginning of the project, we performed several studies to evaluate numerous options for every envelope component, heating and cooling plants, HVAC distribution systems, lighting, power, water and renewable energy. We performed numerous energy model runs to evaluate all the options and then evaluated various combinations. We then performed life cycle cost analyses to help inform the decision-making process.
The systems selected for NASM include a dedicated heat recovery chiller providing chilled water and heating water at the same time; dedicated outside air systems to pretreat the outside air and reduce the need for reheat (a major energy driver in many museums); adiabatic humidification, condensing boilers, a robust control system that responds to the drastic load fluctuations driven by weather and the sporadic attendance of the 7 million visitors a year; digital addressable LED lighting incorporating dimming, daylighting and vacancy controls; and metering of all branch circuits and rainwater and air conditioning condensate collection for reuse flushing toilets and urinals, cooling tower makeup and irrigation.
The two biggest impacts to energy savings were allowing different summer and winter gallery setpoints for temperature and humidity and the LED lighting — these two measures alone will result in savings of 40% energy consumption.
Q: How has COVID-19 changed your work in these facility types? Has the coronavirus affected these projects, by either increasing or decreasing some aspect of them?
A: Every building is different. We review the guidelines provided by organizations such as ASHRAE and discuss options and impacts with our clients. We do believe there will be more emphasis moving forward on items such as filtration, disinfection, humidification and epidemic control modes, to name a few.
Q: How are engineers designing these kinds of projects to keep costs down while offering appealing features, complying with relevant codes and meeting client needs?
A: We implement strategies that solve multiple problems at once. For instance, a small heat recovery chiller can improve energy efficiency, provide night and winter cooling and be backed up on the generator to serve critical cooling loads.
Q: How has your team incorporated integrated project delivery or virtual design and construction into a project? Define the owner’s project requirements and how the entire team fulfilled them using these methods.
A: Energy efficiency starts with the reduction of the loads on the building. We have seen much more attention paid to the building envelope at the earliest stages with preliminary energy modeling to test ideas. For new buildings, the shape orientation, quantity and location of windows and skylights, floor plate depth, perimeter-to-square footage ratio and floor-to-roof ratio, can have a drastic effect on energy consumption, including daylighting and photovoltaics. For all buildings, the envelope material choices for glazing, wall and roof insulation and especially window shading play a role in energy consumption.
Inside the building, close attention should be paid to the lighting systems and miscellaneous equipment. Depending on the building type and systems installed, the miscellaneous equipment loads can account for 50% of the building energy, so anything that can be done to reduce these loads should be evaluated — examples include laptops instead of desktops, sleep mode for computers and monitors, shared copier/printers, smaller/fewer coffee machines and banning personal electric heaters.
Engineering Support for Mission-Critical Systems
On Point with Robert Marino, PE; Tom Syvertsen, PE, LEED AP; Adam Fry, PE; Karen Schulte, PE, CPD, LEED AP BD+C; and Dan Carmine, PE, LEED AP
Since 1976, Mueller Associates has provided engineering services to Northrop Grumman, one of the world’s largest aerospace, research and development, mission-critical, and defense technology companies. Our work has spanned multiple sites and types of assignments, ranging from the design of complex cleanroom and plating technology facilities to large-scale infrastructure engineering. Mueller’s team of experienced professionals serve this Fortune 500 client with extensive expertise, institutional knowledge, and the ability to respond swiftly to new and evolving industry requirements for Northrop Grumman facilities. For this On Point, we spoke to several of Mueller’s leading engineers about what continues to make this partnership successful.
Q. When did Mueller’s work for Northrop Grumman begin?
A. Robert Marino, PE: We started working for Westinghouse, which was later acquired by Northrop Grumman, in 1976. Our first project was for the E3A Test Area, which was testing sites for the Air Force for its Airborne Warning and Control System. Since then we’ve completed more than 1,000 projects—mostly at dozens of sites throughout Maryland, but in several other states as well. We’ve also completed projects in Mexico and Puerto Rico.
Q. What types of assignments has Mueller completed?
A. Tom Syvertsen, PE, LEED AP: The variety of projects is one of the most interesting aspects of our work with Northrop Grumman. A standard project might be an office fit-out or lab equipment utility hook-up project. A more complex project example would be engineering for a 55-foot-high anechoic chamber for “near field” radar testing, in which tight temperature requirements didn’t allow any single point anywhere in the chamber to deviate by more than two to three degrees. One of the more intricate projects might be something like the Advanced Information Management System (AIMS) plating facility, which required connections to specialized equipment with plumbing, spill containment, exhaust with air scrubbing, and corrosive environments. I remember [former Mueller president] Gene Nerf saying it was probably the most complex project Mueller had ever done.
Bob Marino: We’ve done projects ranging from standard office renovations or MEP equipment replacement to challenging tasks such as replacing a cleanroom air handling unit (AHU) in an extremely tight equipment room while the system remains operational 24/7. Many projects involve facilities to test and assemble components for national defense, such as aircraft and shipboard radar systems. Industrial processes might involve acid washes or paint spray booths. One unique project for us involved the replacement of a huge central rooftop AHU that had to be rigged via helicopter due to the physical size of the building and the horizontal reach limitations of a crane. That was tricky enough, but it also had to be done in proximity to BWI Airport runways and flight paths. We had to coordinate with the FAA and other regulatory agencies to get this done.
Q. How is the work for Northrop Grumman challenging or unique?
A. Adam Fry, PE: Northrop Grumman is often working with critical schedules, requiring a fast turn-around. Some projects are so urgent and mission-critical that the project is evolving as we design it—we get a call and get activated but there may still be some uncertainties about the equipment or the utility requirements. We’re learning the requirements as we design, and the designs may be in flux. It requires us to be nimble, flexible, and creative in our approach.
Tom Syvertsen: Sometimes we’re asked to engineer custom systems that are not typically encountered in other industries. For example, we’ve designed a heat transfer skid with a heat exchanger, flash tank, water reservoir, pump, piping, controls, etc., to decouple a press that operates at 650 degrees from its chiller to increase its cooling cycles, by using the reservoir as an additional heat sink.
Karen Schulte, PE, CPD, LEED AP BD+C: In many cases, we can’t take photos on site, so the fieldwork and documentation are critical. We ask a lot of questions, and we’re diligent in the on-site meetings to be sure we come away with as much information as possible. We understand that we are limited when it comes to repeat site visits for surveying and measuring.
Dan Carmine, PE, LEED AP: We collaborate closely with the team at Northrop Grumman. Between the quick turnaround and the potential for changing requirements, we must have strong communications. And as Karen said, because of security requirements, we can’t take photos of the sites, so proper fieldwork is imperative.
Q. How does Mueller stay responsive to on-call arrangements such as the firm’s relationship with Northrop Grumman?
A. Bob Marino: First, we believe it’s important to have several members of our team familiar with Northrop Grumman—their team, facilities, standards, and so forth. Nearly every member of our firm has worked on at least one Northrop Grumman project, and many have worked on dozens. Nearly all of our project managers have deep experience working with this client and these unique projects. We make sure to engage all our staff and share our experience. At this point, with more than 40 years of experience working at their facilities, we bring a lot of institutional knowledge to the work.
We take a lot of pride in this relationship and the important work that is being done at these facilities. For example, we may get a call on a Saturday afternoon about a meeting first thing Monday morning. We have to be agile, creative, and constantly attentive. We’re also vigilant in developing our internal talent to prepare them for this type of work. In many ways, our decades of work for Northrop Grumman have helped shape our company’s professional standards and our culture. It carries over to how we work with all of our clients, regardless of project type.
Plumbing Engineering: An Evolving Profession
On Point with Jeff Edwards, CPD, GPD, chief of plumbing and fire protection, and mechanical project engineers Chuck Swope, PE, CPD, LEED AP BD+C, and Karen Schulte, PE, CPD, LEED AP BD+C
World Plumbing Day on March 11 credits the vital role of the international plumbing community in promoting the link between good quality plumbing, health, environmental sustainability and economic prosperity. In recognition of this important professional service, we talked to three of Mueller’s senior plumbing engineers about the importance of their work.
Q. What excites you about your role as a plumbing engineer or designer?
Jeff Edwards: Having been at Mueller Associates for almost 35 years, I’ve been fortunate to be a part of the majority of Mueller’s amazing projects requiring plumbing systems. From nationally recognized historical sites, museums, and performing art complexes to academic, national zoological park, and laboratory facilities, plumbing system designs play an important role in a new or existing building’s success.
Chuck Swope: Designing a wide variety of plumbing systems certainly makes coming to work easier. I have been involved in the designs of complex laboratories, commercial kitchens, historical renovations, and many others. It’s easy to forget that plumbing is so much more that bathrooms and kitchens. Plumbing engineering also covers fire protection, laboratory and medical gases, chemical neutralization, water treatment, and more. There will always be challenges to solve.
Karen Schulte: Creating environments where the user doesn’t think about the systems I’ve designed is important to me. The “Color Us Invisible” mantra that Mueller has used in reference to our work in historical buildings is resonant with me throughout all our work. If the user can seamlessly use the plumbing systems in the building without a second thought, that’s the outcome I always hope for.
Q. How does plumbing design and engineering impact and help the health and safety of our communities?
Jeff Edwards: All plumbing system designs must take into account that the systems are part of a life safety plan. All plumbing system designs follow strict plumbing codes that have been established to protect building occupants’ health and safety whether using public toilet facilities, getting a drink of cold potable water, or refilling your personal water container. Designing today’s domestic hot water distribution systems to help prevent bacteria such as legionella is a major concern for plumbing engineers and designers. In addition to established plumbing codes, the American Society of Plumbing Engineers (ASPE) provides design handbooks on multiple plumbing systems, technical presentations, and webinars to help keep plumbing engineers and designers up to date with today’s requirements. ASPE also provides a certification process for all plumbing engineers and designers to achieve a Certified in Plumbing Design (CPD) certificate that requires CPD holders to be re-certified every two years.
Karen Schulte: We are privileged to live and work in a part of the world where access to indoor plumbing is a given. The municipal system (whether it’s water, sewer or stormwater) is closely tied to the building design, and we have to be aware of cross-contamination control within a building’s water supply. The codes are a great starting point.
Chuck Swope: Plumbing engineering is a primary defense against water-borne diseases. Our designs help mitigate the risks of coming in contact with infectious wastes as well as keeping our drinking water supplies clean. There are several pathogens that can be reduced simply by maintaining our hot water temperatures above an acceptable level.
Q. What are some of the ways you promote sustainable plumbing solutions?
Karen Schulte: Low-flow fixtures are a part of every design that we work on.
Jeff Edwards: Today’s plumbing system designs for the majority of Mueller’s projects are almost always required to follow sustainability design standards and guidelines whether it’s the applicable plumbing code, LEED (Leadership in Energy and Environment Design), International Green Construction Code (IGCC), and/or the International Energy Conservation Code (IECC). These are all intended to help save water consumption and provide safe potable water.
Chuck Swope: Reducing water use by providing low-flow plumbing fixtures is only the tip of the iceberg. There are many technologies that can capture wastewater for reuse, such as rainwater and ground water harvesting systems. These systems collect water that would otherwise be wasted and reuse it for flushing toilets or in HVAC cooling towers, further reducing our impact on the local water supplies. There are also sustainable methods of construction like using cast-iron and copper piping, which have a long service life and can be infinitely recyclable.
Q. What inspires you about the current and future of your profession?
Chuck Swope: The plumbing industry is ever evolving to include new technologies like rainwater harvesting and sustainable designs, as well as improvements on old designs like condensing storage water heaters that can be up to 99% efficient. Additionally, the industry has great technical societies like ASPE and ASHRAE that are committed to educating engineers throughout their careers.
Jeff Edwards: Being a part of the plumbing system designs for the next great Mueller project is exciting to me along with helping to teach, assist, provide guidance to Mueller’s plumbing engineers and designers—whatever is necessary so we all can complete another successful project.
Modernizing the National Air and Space Museum
On Point with Pathros Cardenas, PE and Robert Broczkowski
The largest project in Mueller’s history, the modernization of the National Air and Space Museum, now under construction, will transform the Smithsonian’s most popular museum with all-new, energy-efficient building systems. The project involved the development of a detailed building information model that will inform the Smithsonian Institution’s stewardship of the facility for future years to come. On Point discussed what it was like to work on this challenging project with two of the team’s engineers.
Q: What aspects of this project stood out for you? What have you learned from this project that you will take to future projects?
A: Pathros Cardenas, Electrical Project Engineer: “This project taught me a lot about the management of time and resources. This was the largest, longest, and most comprehensive project I’ve worked on. I also learned about the real and effective application of codes (NFPA 101 and 70), specifying UPSs, and electric vehicle charging stations. The sophisticated theatrical lighting control systems were also interesting, as was the design of a large distribution power system with 200+ panelboards.”
A: Robert Broczkowski, Mechanical Engineer: “The National Air and Space Museum is the most interesting project I’ve worked on. This project is a monumental design feat for the company and me personally. I learned so many facets of engineering design and learned a great deal about how to coordinate and communicate effectively within a large team.”
Q: What was the one project challenge you found the most interesting?
A: Pathros Cardenas: “Researching the life safety code and applying it to the design of the project in a realistic way, which meant talking with the people who make the codes to see what they meant with what they wrote, and talking to the authority having jurisdiction to assess the extent and applicability of the code in question.”
Q: The NASM renovation has required a closely coordinated team of consultants, working under the direction of the architect, Quinn Evans. What was it like to be part of this talented team?
A: Robert Broczkowski: “One particularly meaningful experience involved a full in-person design ‘jamboree’ meeting. This meeting was used to help all disciplines make concrete design decisions in real-time. It gave me perspective on the true effort that goes into many of Mueller’s challenging projects. I also appreciate the guidance from Mueller's leadership on the day-to-day tasks as well as over the long term. One of our greatest strengths is the attention to detail in our work. There is a constant effort here to uphold and improve standards that drive our work to the highest quality.”
Advancing Careers Through Association Leadership
On Point with Karen Schulte, PE, CPD, LEED AP BD+C
Karen Schulte, PE, CPD, LEED AP BD+C, joined Mueller Associates in 2006 after interning here while she was a student at Penn State University. She has designed plumbing systems for many major projects for the firm and leads the Women of ASPE for the Baltimore chapter of the American Society of Plumbing Engineers. On Point talked to Karen about her association leadership and her career development at Mueller.
Q: What led you to specialize in engineering plumbing systems?
A: In the Architectural/Engineering program at Penn State, I focused on mechanical engineering and HVAC design. We didn’t have a plumbing engineering class. But once I started at Mueller, I had an opportunity to learn both HVAC and plumbing engineering. I think the opportunity to design both disciplines helps you become a better mechanical engineer. We’re all trying to use the same space in the building as we design systems, so the coordination is important.
Q: You’ve had a chance to become involved with ASPE. How has that helped your career?
A: ASPE has really helped me in my career development in plumbing engineering. They have monthly meetings with technical sessions for continuing education. These sessions really further your education and introduce you to new technology. I’ve been attending these meetings for several years now.
Q: You’ve recently become more active in local ASPE leadership. What opportunities have you had?
A: Jeff Edwards, who is Mueller’s chief of plumbing and fire protection and serves as president of our local chapter of ASPE, asked me to head up Women of ASPE for the Baltimore Chapter. Our chapter didn’t have Women of ASPE so I was pleased to start this group. It’s been an important networking and support group. We’ve had good turnout at our events and I’ve enjoyed the camaraderie. We have both engineers and product representatives take part. I also had the opportunity to attend the ASPE national conference in Atlanta recently. There was a day dedicated to the Women of ASPE, with speakers addressing diversity and professional development. It was great to get their take on things, and it gave me ideas for events we could do locally.
Women of ASPE Paint Night
Q: What project stands out for you at Mueller? What has been interesting to work on?
A: The Bird House at the National Zoological Park in Washington, D.C., has been fascinating. It’s been interesting to approach the project knowing that the most important occupant is not the public, it’s the birds. As an engineer, you have to change your mindset. We’ve needed to create the best living environment for the birds, with extensive plumbing systems. The birds need filtered and tempered water sources, while on the public side, we also need to supply a domestic potable water system. It’s just starting construction. I’ve learned a lot on this one—it’s been incredibly interesting.
Sustainable Design: Smart Strategies at Work
On Point with Todd Garing, PE, LEED AP
Todd Garing, PE, LEED AP, a vice president with Mueller Associates, has helped engineer several of the firm’s high-profile sustainable projects, including the award-winning UMBC Performing Arts and Humanities Building. On Point explores Mueller’s “green culture” with Todd, as well as the latest on the firm’s LEED® projects.
Q: Mueller has a diverse portfolio in sustainable design. What projects have been unique?
A: It’s interesting—one of our earliest projects that focused on conserving energy was for the White House in the 1970s. We designed a solar energy system there. That was before my time, but I did have the opportunity to work on another historic property, at Thomas Jefferson’s Monticello. The visitor center there is a LEED-Gold project, and it incorporates an innovative geothermal chiller/heater system. We like to think that Jefferson would have approved—it was cutting-edge but organic in that it made good use of the land.
Q: What are some of your significant LEED projects?
A: Two of our higher education projects have achieved LEED Platinum: the Angelos Law Center at the University of Baltimore and the Center for Natural Sciences, Mathematics, and Nursing at Bowie State University. Both of these projects incorporated cutting-edge technology. The Angelos Law Center has radiant heating and cooling in the slab floor. The Center for Natural Sciences features chilled beam technology. At the LEED Gold University of Maryland Eastern Shore, the Engineering & Aviation Science Complex, we incorporated geothermal technology.
Q: How has the firm approached the challenges of incorporating sustainable design measures?
A: We’ve been working with institutional spaces for many years, so we’ve always had a focus on energy conservation—incorporating control strategies and more efficient equipment, or laying out the pipe and ductwork in a more effective configuration. The LEED process has essentially validated much of what we have been doing over the years. The focus has evolved so that it is not just an energy and cost-saving focus, but we are thinking more broadly in terms of environmental awareness. It challenges us to think in terms of each and every detail and what can be done more effectively to conserve resources.
For example, many people don’t realize how much water is produced through A/C condensate. For the University of Maryland Baltimore County Performing Arts and Humanities Building, we were able to predict that as much as 40,000 gallons of water from condensate could be collected a month during the summer. That’s a lot of water—it could be used for toilets, irrigation, or cooling tower make-up. For that project we utilized the A/C condensate as well as the rainwater collected from the roof to serve the irrigation system.
Q: How integral are sustainable strategies to the firm’s work? How much of Mueller’s staff focuses on this aspect?
A: The sustainability framework guides all of our projects—it’s inherent in our approach and our process. What is exciting to us is that the LEED process really taps into the “brain power” of the firm. We have a lot of smart people here—people who are good at coming up with ideas and new strategies. A large percentage of our professional staff is LEED accredited, so it has become integral to our practice and the way we approach our work.
Mueller: A BGE Service Provider
On Point with John Morris, PE and Ken Rock, PE
John Morris, PE, and Ken Rock, PE, have provided leadership for the past year in the firm’s role as a BGE Service Provider. On Point reviews the highlights of the program with the two Mueller vice presidents.
Q: What is a BGE Service Provider? What does this mean for Mueller clients?
A: Ken Rock: BGE encourages architects, engineers, and contractors to become participating Service Providers through the company’s Smart Energy Savers Program®. The program focuses on energy efficiency through products and services, and helping clients realize lower operating costs.
The rebate program addresses energy-saving measures that exceed the minimum energy code requirements. These range from straightforward upgrades, such as the use of occupancy sensors for lighting controls, to complex, prescriptive programs for custom systems. These require upfront capital costs, and BGE helps model the energy and cost savings so clients can forecast the long-term value.
Q: What’s involved with becoming a Service Provider?
A: John Morris: Training is important. BGE, with the support of ICF International, offers a robust program of training and seminars. It begins with an introductory half-day of training, and continues with occasional seminars that help keep providers up to speed on energy-saving tools and strategies.
Q: What’s covered in the training and ongoing seminars?
A: John: Some of the topics are procedural, and relate to the application process for rebates. For example, a recent seminar covered the specifics of the rebate program, and the BGE calculation tools available to quantify energy savings. BGE prefers that applicants go through the training in order to understand the paperwork—how to complete the forms and required calculations. Other topics focus on energy-saving equipment and strategies, such as the benefits of different types of lighting fixtures and controls.
Q: What types of clients benefit from Mueller’s role as a Service Provider?
A: Ken: All types of clients in Maryland can benefit. The Smart Energy Savers Program is driven by the Empower Maryland legislation, which requires that the utilities show energy savings. BGE offers a number of incentives to building owners. Several of our state clients in particular, such as universities, are interested in this opportunity.
A: John: Several of our current projects involve rebate applications. The new Law School at the University of Baltimore, for example, has several custom energy-saving features that will qualify. We have submitted an application for that project as well as the Johns Hopkins University Lacrosse facility. The University of Maryland at Baltimore Pharmacy School has been awarded a rebate, and we will also be submitting an application for the Morgan State University Business School. There are a lot of opportunities for rebates for existing facilities as well, such as lighting retrofits, putting variable speed drivers on motors, and HVAC equipment replacements. These all qualify for rebates.
Revit®: The Standard for MEP System Design
On Point with Rebecca Fischer, PE, LEED AP BD + C
A mechanical project engineer, Rebecca Fischer is a graduate of Penn State and has worked with Mueller Associates for nearly nine years. She has been using Autodesk’s Revit® and Navisworks® software for building information modeling (BIM) since 2006.
Q: What was your introduction to Revit? What were your early impressions of the modeling software?
A: I’ve been using Revit MEP here at Mueller since 2006. I graduated with my engineering degree in 2003, and the program didn’t exist when I was in school. Our management at Mueller recognized early on that we needed to embrace this technology, and provided us with comprehensive training. We saw where the industry was going.
Our first project using BIM was the new Visitor & Admissions Building at the University of Delaware. At first, the software was not as well suited for mechanical/electrical engineering, but it has improved by leaps and bounds.
Q: What has improved since your earliest use of the software?
A: At the beginning, we were only able to model ductwork and electrical systems. Now, we have the ability to model just about every mechanical, electrical, plumbing, and fire protection system. We can do the electrical panel schedules, which we couldn’t do before. The software has advanced tremendously, and our own training and proficiency has improved. Our entire professional and production team is trained in Revit. It makes it a lot easier when we’re using the technology across the board, rather than having just a few Revit “specialists.”
Q: How many of Mueller’s current projects are using BIM technology?
A: Nearly all of them. It’s one of the biggest differences from three or four years ago. Nearly every project, including our university and museum work, is done in Revit today. It’s become the standard, especially for large projects.
Q: What advantages do you see as you work with BIM?
A: The software really lends itself to a much more integrated approach to design. We can see the other disciplines’ design intents in a 3-D environment, with real-time updates. We export the models to Navisworks so that we can do our own clash detection. Mueller also has a comprehensive Revit-based library with details on equipment and fixtures. It streamlines our design time and effort and can be used to support life cycle and maintenance programs.
Q: How do you keep current with updated programs?
A: We participate in the Autodesk user groups and Autodesk University. I’ve also had the opportunity to visit the Autodesk offices in New Hampshire and test their last two Revit MEP products prior to release and provide feedback. We have a lot of knowledge about BIM in this office and that’s based in part on our experience but it’s also a result of our commitment to continue to learn and take advantage of the latest resources.
An Intricate Puzzle: The University of Baltimore Law School
On Point with John Morris, PE
In 2008, Mueller Associates was selected as part of the Behnisch Architekten/Ayers Saint Gross team to design the mechanical systems for the new University of Baltimore Law School. Mueller Vice President John Morris, PE, led the engineering effort for this innovative, award-winning project, which opened in 2013.
Q: You’ve been a mechanical engineer for more than 25 years. How does this project rank in terms of complexity?
A: It’s certainly [one of] the most complex projects I’ve ever worked on. The design was very ambitious in terms of the sustainable strategies and Behnisch’s objective of keeping the spaces very clean and streamlined. The basic design of the building, with its interlocking forms, has been described as a puzzle, and for us, integrating the mechanical systems into the spaces was like an intricate puzzle as well. At 12 stories and 192,000 square feet, it was also a very large project to manage.
Q: What sets this building apart from other large projects you’ve worked on?
A: There are several features that made this project both interesting and challenging. One is the thermally active (radiant) slab flooring, which is used for both heating and cooling. This is a little more common in Europe but hasn’t been implemented on many U.S. projects. The slabs were 11 inches thick and there was a lot of infrastructure to accommodate there—electrical conduit, PEX tubing, security conduit, and so forth. The automated natural ventilation system is another key feature. There was a lot of testing to be sure that everything worked properly in terms of humidity control. The windows in the curtainwall system open and close automatically depending on outdoor ambient temperature and relative humidity.
Q: Are there other building innovations that you were working with?
A: Yes. The automated shade control system is an important feature of the building from a climate control perspective. There are operable shades along the façade between the curtainwall and the rainscreen system. Solar sensors on the roof track the sun’s radiation and trigger the automatic opening closing of the shades to control solar heat gain. Also, if the wind speed becomes too high, the shades automatically retract to prevent damage.
Q: Much of what you describe is automated—can people jump in and control the settings as well?
A: Yes, the building is designed to be “smart,” but there is a lot of flexibility. The audio-visual system is tied into the shade control system, for example, allowing for manual adjustments in the amount of natural light. In private offices, occupants get a signal—a green light when ambient environmental conditions are favorable—that lets them know that they can initiate natural ventilation themselves by opening and closing windows.
Q: Are there other sustainable aspects related to the mechanical engineering?
A: There is a dedicated outdoor air system with a heat recovery wheel and a passive desiccant wheel that helps drive down the humidity level. The energy recovery wheel utilizes exhaust air to preheat or pre-cool the outdoor air as necessary. Other sustainable features include high-efficiency chillers and boilers, water-conserving fixtures, and a rainwater harvesting system.
Q: How important was BIM to the design of this building?
A: BIM really helped to facilitate the design. Whiting-Turner, the construction manager, created BIM models of the slabs, which was important. All of the modeling helped with the intricate integration of the systems with the structure. There are a lot of exposed concrete finishes in this building and BIM helped us create a clean look.
The Right Fit: Chilled Beam Technology
On Point with Darren Anderson
Chilled beam technology is seeing increased use in the U.S. as an energy-efficient option that can lower long-term operating costs in buildings. Darren Anderson, PE, CPD, LEED AP BD+C, an associate with Mueller Associates, discusses the advantage of using chilled beams and how the technology can impact the overall design of a building.
Q: What are the basics on chilled beam technology? How does it work?
A: Active chilled beam systems use conditioned air supplemented by ceiling-mounted chilled water heat exchangers. The beams receive air ducted from a central air handling unit and water piped from a central chilled water system. The amount of water varies in order to maintain a comfortable temperature in the space. The ducted air passing through each beam induces room air to flow through its heat exchanger, cooling the room as it circulates. The amount of air delivered to each space is minimal—often only the amount required for ventilation.
Q: What are the benefits?
A: Using water in a chilled beam heat exchanger to remove heat, rather than using conditioned air, is more efficient. Water can carry more energy than air, and this leads to lower operating costs. First costs to use chilled beam systems for an entire building are similar to costs for variable air volume systems when you factor in other design considerations. Chilled beam systems are more expensive than air-only systems with traditional air diffusers, but the ductwork and air handler capacity needs are reduced. There may also be less space required for the mechanical room and ceiling area.
For tenants or building users, the technology can offer increased comfort, with more temperature control zones and better indoor air quality.
Q: What types of spaces are appropriate for chilled beam technology?
A: We are seeing an increased interest in chilled beam systems for laboratories in particular. Labs often house a lot of heat-generating equipment. The air cannot be recirculated, which can lead to high energy costs. The use of chilled beams assists in reducing the required airflow because the amount of air is driven by ventilation and not by the need to remove heat from the equipment. This lowers the overall amount of energy used.
Q: Does Mueller have any current projects that incorporate this approach?
A: We are currently assisting Perkins+Will in the design of the new Natural Sciences, Mathematics, and Nursing Center at Bowie State University in Maryland. Perkins+Will has had success with the chilled beam approach and has been a proponent from the start of this project. The building has a number of laboratories and was a good candidate for using a chilled beam system.
Q: How has chilled beam technology made a difference on the Bowie State University project?
A: Incorporating chilled beams in the Natural Sciences, Mathematics, and Nursing Center has had a dramatic impact on the overall design. It has been very interesting to see how this technology can alter a design and have a positive impact on the overall cost.
Because the ducts required for the chilled beam system are smaller, the design team was able to reduce the building height by one foot on both the second and third floors. The two-foot reduction overall will save the university more than $300,000, which offsets the cost of the chilled beam system and lowers the life cycle cost of the building as well. Part of the cost-savings is a result of the smaller amount of dynamic glazing needed for the exterior windows, because of the reduced height.
Chilled beam technology is a strong option for new buildings, with a number of clear benefits. In our experience, the best results—and potential cost-savings—occur when the architectural and engineering team works creatively and in close collaboration, to be certain those benefits are realized.