Learning how to engineer colleges, universities better: HVAC and plumbing
Fletcher brings more than 15 years in the construction and real estate development industries to the company. He is an active member of industry organizations such as the Urban Land Institute, Smart Cities Council and Orange County Business Council.
TLC Engineering Solutions
Fryman has managed the engineering team for numerous higher education facilities, predominantly for public universities in Florida. His range of experience extends from fitness centers to highly sophisticated laboratory buildings and housing to university administration buildings, commonly attaining LEED Gold certification or higher.
Henderson Engineers Inc.
As Vice President|Higher Education Practice Director, Holden works on local, national and international projects. His areas of specialty include higher education, medical education, K-12 schools and sustainability-focused projects.
As senior associate, O’Connell’s primary responsibility is managing the company’s electrical department. He keeps current with industry trends such as green building design and LEED certification to educate other staff.
David K. Piluski
Piluski has more than three decades of experience designing MEP systems for a broad range of new construction projects as well as renovations. His specialties include higher education, health care and restaurant/entertainment facilities.
Affiliated Engineers Inc.
As principal and project manager, Sherman offers expertise in higher education research labs and health care facilities, During his tenure, he has led more than 2 million square feet of functionally complex facility projects.
Randy C. Twedt
Since joining the company 25 years ago, Twedt has worked on a diverse range of MEP projects. His contributions include medical projects, multiunit residences, university structures, courthouses and more.
Jeffrey P. Wegner
Since joining the firm in 2013, Wegner has worked on a range of projects, focusing on life sciences, biotechnology, pharmaceutical, aerospace and other high-tech projects. His expertise includes site utility master planning, alternative energy solutions, biocontainment and more.
CSE: What unique heating or cooling systems have you specified into such projects? Describe a difficult climate in which you designed an HVAC system for a college or university project.
Twedt: We designed an anatomy lab for a large university and specified chemical detection to convert the AHU from recirculation to 100% outside air depending on the chemical levels detected. This resulted in substantial energy reduction for the lab.
Sherman: We have been designing a lot of decoupled HVAC systems over the last 10 years. It is much more efficient to pump heating hot water and secondary chilled water around a large facility than it is to force air. Reducing the air to the minimum amount of ventilation required for the facility is the key to success.
The majority of the buildings we design out of my office are in North Carolina. Clients are concerned about using distributed cooling devices in the southeast because of the humidity, fearing condensation in the space. The entire East Coast is humid, so it is no different installing these systems whether it is North Carolina or New Jersey. As with all modern HVAC systems, the latent load needs to be handled at the AHU to avoid the possibility of condensation on the distributed cooling coils. The building control system is used to monitor the space dewpoint in the building and reset the secondary chilled water temperature upward to maintain it at 2°F above dewpoint.
Fryman: At the University of Florida’s Joseph Hernandez Hall, the first–floor general chemistry teaching lab has 128 lab stations arranged at 32 work benches that each has four small, custom designed mini-fume hoods; affectionately called “hoodies.” The hoodies are collapsible and can be stowed away under the bench. These 128 hoodies are served in groups of 32 by a trunk line exhaust duct that runs in a trench under the floor with all the other utilities and systems that serve the benches. Since the benches can be broken down and rolled away, the connection to the hoodies from the trunk line is a flexible stainless–steel duct with a quick releasing flange. This allows for the removal of the benches to use the space for another function, if desired. If the hoodies are all operating simultaneously the makeup air system supplies fresh air to replace the air being exhausted from the room. If the hoodies are collapsed and stowed when the curriculum does not require them or in the event of a smaller class, like may occur in summer terms, the exhaust system trunk lines can be individually closed and take 32 hoodies at a timeout of the exhaust system. The makeup air system will automatically decrease its supply of fresh air to match the exhaust of the remaining hoodies. This results in greater energy efficiency in the reduction of exhaust air and the need for less conditioned makeup air.
O’Connell: Working with existing buildings can be challenging when determining systems that may be feasible. We are currently designing systems for an existing university classroom building, which will use campus chilled water/steam, a DOAS and active chilled beams. When designing this system, it was important to review the existing building envelope and coordinate with the architect on the necessary improvements required to the envelope to ensure the HVAC system operates efficiently.
Piluski: Many of my projects have been in Wisconsin and northern Illinois, which if you are from there, you may consider a difficult climate. Swings in temperature and humidity result in systems needing to be able to changeover from heating to cooling and vice versa often within the same day and use of natural ventilation is very limited as compared to more temperate zones. Systems must be robust and backup measures should be employed to address possible failure of the primary system components, particularly in the area of heating systems to prevent freeze damage. Additionally, two-pipe changeover systems possibly employed in other climates, are not a good solution for the rapidly changing conditions in these zones given the mass of water needing to change temperature before a full changeover can be realized.
CSE: What unusual or infrequently specified products or systems did you use to meet challenging heating or cooling needs?
Piluski: I am currently working on a project for Carthage College in Kenosha, Wisconsin. The building is the college administration building, which was built in the mid–1960s and has seen minimal upgrades since that time. The HVAC system is a multizone hot deck/cold deck system that uses structural cavities and tunnels within the poured in place concrete structure to facilitate air delivery and serve as ductwork. Actual ceiling space is limited to approximately 12 inches with ceilings being suspended as low as 8½ feet. As a result, we are designing an HVAC retrofit based on VRF systems with DOAS providing ventilation requirements. This allows for enhanced control on a room by room basis, while switching the energy conveyance media from the air system to the refrigerant system allowing for conservation of the limited ceiling space. VRF fan coil units can fit in the limited vertical space of the ceilings and ductwork is sized to only deliver the ventilation needs of the spaces at a neutral air temperature.
Sherman: Wrap-around heat pipes are a great technology for the DOAS that we are designing. We are trying to deliver drier air than typical to our buildings so that the air has more ability to hold moisture. Any building that is artificially overventilated (like a research or teaching laboratory) is a perfect candidate for this technology. For a very small amount of airside pressure drop, we get precooling of the outside air and free reheat. You really need to be in a cooling/dehumidifying climate for this technology to be most effective. Any locale from Washington, D.C., south should be a really good candidate.
Twedt: A new product that we are using more frequently is a smart glass technology. Halio smart tinting glass is responsive and reacts to sun on the building. Smart glass technology can dramatically reduce cooling loads to the space via actively adjusting and minimizing solar heat gain through the windows.
O’Connell: In several instances we have implemented thermal ice storage as a means of offsetting utility costs. This allows us to design a reduced sized chiller plant, which is supplemented with the thermal ice storage to meet the buildings peak cooling capacity.
CSE: How have you worked with HVAC system or equipment design to increase a building’s energy efficiency?
Fletcher: I often look at the life cycle and maintenance programs. A large part in energy efficiency and life cycle cost-savings is related to maintenance of the equipment in these buildings and systems.
O’Connell: has regularly worked with equipment manufacturers and our energy modeling department to determine if providing energy recovery, when not required by code, would be beneficial to the project. While energy recovery can initially seem like a great energy–efficient measure, it is important to understand its impact on the overall system. Having an understanding on how increased air pressure drops, energy recovery wheel and/or supply/return motor sizes impacts energy consumption is important to ensure that long-term benefits are truly provided. Payback periods significantly beyond anticipated equipment life may not provide benefits to the owner they are willing to consider that requires a higher initial investment.
Twedt: Often for networks of university lab buildings, we design complex control systems that allow the buildings to perform at maximum efficiency. For example, the integration of the exhaust hoods and HVAC systems in the buildings is important to allow the systems to ramp up and ramp down depending upon occupancy, which increases efficiency while reducing costs. It is also important for users to have the flexibility to modify their environments when they are occupied.
Piluski: Controls are the key component of any final selected system. While systems must be designed to address a variety of factors including code compliance, energy conservation and owner preference, improper or ineffective controls will hamper even the most advanced systems. Integration and well–planned control sequences, along with commissioning throughout the design and construction process, is imperative to correct functionality. Coupled with this, training of the end users and maintenance staff is necessary to impart understanding of operations and establish expectations, especially if the designed system is unique to the campus or building.
CSE: What best practices should be followed to ensure an efficient HVAC system is designed for this kind of building?
Twedt: As an integrated A/E firm, our design approach combines BIM and building performance analysis results to “remodel things less,” better capitalize on our architecture and engineering practices, proactively communicate performance opportunities and inform a data-driven approach to design. HVAC systems can no longer be designed without regard to other disciplines. Involving cross-discipline efficiency measures is critical to ensure all sustainable design features are working synergistically.
Fryman: College and university buildings always have a widely varying occupant loads due to large classroom or auditorium spaces being used on varying schedules depending on class schedules and the academic calendar. There are also considerable blocks of time between semesters where buildings will have almost no occupants. Two common strategies for energy efficiency in HVAC systems in these types of buildings are demand controlled ventilation and heat recovery from exhaust air through dedicated outside air units. We can also reduce outside air requirements in labs using fume hood controls to monitor sash positions and occupant detection in front of the hood.
Piluski: I cannot emphasize enough the value or early planning and education of the end users about the options and performance of the systems under consideration. The most efficient systems conceivable will not prove satisfactory if the users cannot operate them or if aspects of their expectations are not addressed effectively.
Sherman: We need to make better use of the data and capabilities inherent in our BAS. Alarm optimization, fault detection and diagnostics, key performance indicators, data storage, measurement and verification and point naming are all things that we try to stress with our clients. All of the major control vendors can incorporate all of these items within their systems when they are given the proper direction. Clients that understand the value of trying to effectively and consistently incorporate these design parameters into their design documents benefit greatly in the long term by having buildings that function the way everybody envisioned during design, saving both energy and maintenance resources.
CSE: What is the most challenging thing when designing HVAC systems in such buildings?
Piluski: In existing buildings the primary challenge is the existing structure and space constraints. These were often buildings originally designed before highly efficient technologies were available. In all buildings, the main challenge is meeting and exceeding code requirements and designing highly efficient systems while managing budget and expectations at the same time. I try to put myself on the other side of the table, as the owner’s advocate, when making any decisions or recommendations impacting budget.
Sherman: Convincing all the stakeholders on the project of the value of the systems that we are designing. Most owners, architects, construction managers and even mechanical contractors haven’t installed the type of decoupled systems that we are designing. There is usually a lot of education that we have to engage in with all of the main stakeholders to make sure everybody is comfortable with the systems. We have many tools that we can use to help build consensus. Affiliated Engineers Inc.’s graphic illustrators create wonderfully understandable diagrams that we can share with both technical and nontechnical team members to get the concepts across. Additionally, we routinely tour these groups through our existing buildings and show them the systems in person in a working environment. It also gives them the ability to talk to the people that actually work on these systems, so they know exactly what to expect.
Fryman: When beginning the design for higher education buildings, it is important to meet with the users of the building to determine the actual expected operations of the building. This is important to develop appropriate schedules of use to provide appropriate demand controls based on occupancy and any necessary setbacks based on scheduling. These are important to know up front to perform accurate energy models to develop the system types. These schedules can change over the life of the building or even during the timeframe of the design process. We have to design the building systems with a balance between the best system for Day One and versatility for what may come in the future.
O’Connell: With the increase of technology in buildings and the need for fire protection, ceiling cavities have become congested. Coordinating the routing of these systems above the ceiling requires additional time during design. In addition, as systems become more efficient, the size of the equipment does not necessarily become smaller in footprint. Allocating appropriately sized rooms to house equipment so that distribution can easily be routed and maintenance can be performed is always a challenge.
Twedt: Space allocation is a constant challenge. There is often tension between the design team, seeking the highest ceilings possible and the contract, looking to reduce costs. Routing the HVAC systems is often the element that suffers due to the dynamic.
CSE: What unique HVAC systems have you specified for campus dorms? How do you help engage and educate the students with this design?
O’Connell: At a previous dormitory project at Fairfield University, a building energy dashboard system was displayed within the entry lobby for the building. The dashboard system displays energy consumption and water use by the students. It helped to educate students on average water and electricity usage on a daily basis. The system also allowed for competitions to be held between the floors of the residential building and which floor could have the lowest energy use. This knowledge can be used to help students understand the benefits of turning off lights and/or faucets when not in use.