High standards for labs, research buildings: Automation and controls
Laboratory and research facilities are high-performance buildings, often with complex systems and exacting standards for engineers to meet. Building automation and management systems often are employed.
- Bryan Laginess, PE, LEED AP, Senior associate, Peter Basso Associates, Troy, Mich.
- Jeremy Lebowitz, PE, Vertical market leader, Rolf Jensen & Associates Inc., Framingham, Mass.
- Brian Rener, PE, LEED AP, Associate, SmithGroupJJR, Chicago
- Joshua Yacknowitz, PE, LEED AP, Associate principal, Arup, New York City
CSE: According to a recent Consulting-Specifying Engineer poll, automation and controls are the biggest challenges for engineers working in laboratory/research facilities. Do you agree or disagree, and why?
Yacknowitz: I am fortunate in that I work in a firm that is large enough to have a dedicated controls group who have a good deal of laboratory experience, so while the design of these systems is quite complex, I don’t find it to be difficult to find the resources to do it properly. I would agree from the perspective of interdisciplinary coordination, though. It is extremely important for all disciplines (including architecture and MEP, fire protection, and IT) to understand how they would like their respective equipment and systems to be controlled, and to be able to articulate a user requirement (for lack of a better term) to the controls engineer who is developing the control diagrams and sequences of operation. The places I see disconnects are where standard control sequences have been improperly applied for very user-specific applications.
Rener: I agree. Interoperability and integration between various building systems and the main BAS are challenges. Competing standards, protocols, and interfaces remain as obstacles. Specifications usually need to remain open to competitive bidding, and this makes writing specifications for equipment that can all communicate effectively a major undertaking. Bid evaluations and shop drawings reviews must be carefully performed to ensure interoperability among vendors and suppliers.
Laginess: It can be, especially in facilities with variable volume fume hoods. Maintaining proper velocities across the face of the hood as the sash height changes, and maintaining proper room pressurizations while this happens, requires a lot of communication between various equipment, and it all needs to happen very quickly.
CSE: When designing integration monitoring and control systems, what factors do you consider?
Yacknowitz: In the case where there is no user requirement specification, it is very important to engage the relevant stakeholders early in the design process to ferret out the expectations of all involved. I find there are often conflicts between the expectations of users, facility managers, and environmental, health, and safety (EHS) managers, and these need to be resolved before the automation system design is finalized. It is easy to “gold-plate” a controls design and add a lot of first cost to the project because the owner seldom gets far enough into the details of the controls design to challenge the design basis. It is therefore important to have the early discussions and clearly document what decisions have been made related to the extent of automation, monitoring, and reporting that is required. Another consideration is that many lab projects go for U.S. Green Building Council LEED certification, and often go for the measurement and verification (M&V) credit. There is fairly wide latitude in terms of design approaches to meet the International Performance Measurement and Verification Protocol (IPMVP) standard, and the right approach for any given project also needs to be discussed with the relevant stakeholders to avoid excessively complex and costly systems. Another consideration is any integration required with legacy building or campus-level control systems, and the impact on control platform selection. Finally, there is the painstaking coordination that needs to take place with all equipment and systems that touch the control infrastructure, extending beyond typical HVAC to things like scientific furniture, lab equipment, prefabricated rooms, and so on.
Rener: It’s important to decide which systems will be controlled versus monitored. Any number of systems can only be monitored on a basic level—and control or full information sharing is limited by either that manufacturer’s protocols or by code restrictions which do not allow a building management system (BMS) to control it.
CSE: What are some common problems you encounter when working on a BAS?
Yacknowitz: One common item is coordination of controls infrastructure with specific equipment packaged controls, particularly when a design-basis equipment selection is substituted by an alternate that has slightly different standard factory controls options. Another is the integration of laboratory airflow control systems with BMSs, which requires a lot of careful consideration during design to understand the options and limitations of the various control platforms being considered (not all of them are alike).
Rener: Most common problems are encountered during construction and building start-up. This is where the value of commissioning comes in, and ideally the commissioning agent should be on board during design to review the control basis of design.
CSE: Describe a recent laboratory/research facility project in which you integrated HVAC, lighting, and/or daylighting with the building automation or building management systems.
Yacknowitz: At Columbia University Northwest Corner Building, we designed a fully integrated BMS including laboratory airflow control system (LCS), M&V system, lighting/daylighting controls, and critical laboratory equipment monitoring. The BMS was the overarching system integrating all control subsystems, with a front-end interface in the building, and integration with the existing campus front end. The BMS interfaced with equipment level controls on all major air-handling systems, critical chiller plant, central compressed air/vacuum systems, local fan coil units, campus steam pressure reducing station, campus chilled water flow control and metering, steam-to-hot water converters for heating and potable hot water, and a variety of other systems. A full M&V system was incorporated, including trending, graphical user interface, lighting energy monitoring, campus chilled water/steam energy metering, critical chiller plant energy metering, service hot water metering, laboratory exhaust air heat recovery metering, and a number of other systems. Lighting control was predominantly via occupancy sensors, with daylighting control on perimeter areas using local light level sensors. Specific critical laboratory equipment and systems, such as environmental rooms and areas with hazardous gas or oxygen depletion monitoring, was monitored by the BMS, with e-mail notification to key personnel for specific critical fault conditions.
CSE: What types of cutting-edge control systems have you specified into these buildings? What type of push-back are you receiving from the contractors, clients, or other team members?
Yacknowitz: One mechanical cooling approach gaining traction in the laboratory sector is use of active chilled beams in certain lab types where recirculated air is allowable. There is still some hesitancy among institutions that are leery of these systems due to the potential for condensation, but it is being accepted more widely each year. From a contractor’s perspective, chilled beams are a “finish” item, which is visible in the ceiling and needs to be coordinated and installed carefully for appearance as well as performance, so there are sometimes premiums attached to this from a labor perspective. Another interesting technology is demand control ventilation for labs, which uses pollutant monitoring technology at the room level to allow lower minimum air change rates during unoccupied hours. This technology does not detect every conceivable hazardous substance, however, so careful consideration with the user and EHS management needs to occur to evaluate the risks. In mixed-use buildings where there are zones using traditional recirculating air-handling systems, there is an opportunity to use spill (system exhaust) air from central air handling units as a component of inlet air to the laboratory once-through air handlers. This lowers the enthalpy change required in the lab air handler, thus reducing the energy cost and thermal plant sizing needed for lab operation. This approach needs to be considered carefully with regard to potential levels of CO2 from densely occupied nonlab spaces, which might cause problems with the lab indoor air quality. For interdisciplinary labs where the lab infrastructure and plan are intended to allow for flexibility of programs over the life of the building, some interesting discussions often occur around the method of energy recovery to be used on the lab air exhaust system. The safest approach from an air cross-contamination perspective is to use glycol loop or heat pipe systems. However, these systems allow only for sensible energy recovery. Plate-type heat recovery systems can achieve a somewhat higher effectiveness but can still only transfer sensible heat, and their thin-foil construction raises some concerns with particularly aggressive corrosive chemicals. Enthalpy wheels offer the highest potential heat exchange effectiveness in that they can recover latent energy as well, but these systems have a small amount of leakage between the two airstreams, and contain media that may be degraded by certain types of chemicals. A risk-based approach to energy recovery system selection is therefore needed, and the discussion is most productive when the user, operations, EHS, and design teams are engaged.