Building automation for hospitals, health care facilities
Neal Boothe, exp Global Inc., Maitland, Fla.
David W. Crossey, Principal/Vice President, Lovorn Engineering Assocs. LLC, Pittsburgh
Jeff Harris, PE, LEED AP, Director of Mechanical Engineering, HGA Architects and Engineers, Minneapolis
Michael McLaughlin, Senior Vice President, Southland Industries, Washington, D.C.
Michael Sheerin, PE, LEED AP BD+C, Principal, Director of Health Care Engineering, TLC Engineering for Architecture, Orlando, Fla.
CSE: What factors do you need to take into account when designing building automation and controls for a hospital building?
Harris: Hospitals tend to have hands-on facilities personnel, and their needs and requests are some of the earliest and most important criteria for the building automation system (BAS). Other factors are the need to provide a system that will help the client’s hospital become more energy efficient, by making trending and monitoring of the systems as easy and user friendly as possible. Many of our projects are additions to existing hospital campuses, where there is a legacy BAS. The challenge is in providing specifications that allow for competitive bids while integrating the new controls into the existing control system.
Sheerin: We strive to make the user interface a help to the hospital staff in operating the building so compel an early look at what that graphic will look like. Likewise, we try to review the operating sequences with the staff during the design or shop drawing phase; this way they understand the intent and we can make final adjustments with their input.
CSE: When re- or retro-commissioning hospital control systems, what challenges to you encounter, and how do you overcome these challenges?
Harris: One of the first challenges is data points or equipment that are not picked up on the BAS. These need to be trended by data loggers, which takes time and still only provides a partial snapshot of system performance. With older pneumatic temperature control systems, the operation of the system under changing conditions needs to be visually observed. Another challenge for hospitals is the areas that can’t be shut down during testing. Sometimes, in order to commission the systems, the systems need to be switched to the “hand” position while the conditions are “faked,” and the commissioning personnel need to watch the software triggers without actually causing the equipment to change operation. This is closely related to another challenge, which is the lack of documentation for older systems. Equipment has been running in “hand” position or with setpoints overridden for so long that no one remembers how it was supposed to work. Sometimes the solution is to dig into the software of these systems and see how the program was originally designed. One issue that comes up repeatedly is dampers and valves that read 0% at the BAS but are actually leaking. This requires visual observation of dampers, and for valves, we have measured the temperature at a coil where a valve is reading 0% open, then close the manual shutoff valve and see if the coil temperature changes with the manual valve closed.
Sheerin: In many cases, we find that the equipment is too far gone (too old, out of useful life) to perform, so we have to explain to an owner that it needs to build a capital program to replace it. That can be a challenge, as you hate to be the bearer of the news. In many cases, the owner finds it a help as it provides a third-party report of something that it has been warning its executive leaders about for a while.
CSE: What new control technologies or BAS have you recently specified into a hospital?
Crossey: On a recent project for a hospital in Pittsburgh, we were required to design patient rooms for variable acuity levels. From the HVAC aspect we needed to be able to provide the required air rates depending on the way the room would be used—as a normal patient room, a critical care room, or an isolation room. Each room needed to work independently to maintain its own set of pressure and air change requirements. We used venturi air control valves in conjunction with variable speed controls on the air handling unit (AHU). All of the controls are available through the BAS, but we provided a local control with a selector dial so that the nursing staff had control over the operation of the room.
Harris: Recently, we have been able to modify existing chilled water systems to primary variable speed pumping. For two different hospitals (in different regions), we were able to take a primary/secondary chilled water pumping system, and through the addition of additional cooling capacity and the reconfiguration of the piping in the central plant, were able to decrease energy use (on a per-ton basis) and increase capacity, resulting in a real benefit to the owner. Trending capabilities of the BAS, and specifying that they are set up and that the owner’s facility personnel know how to use them, have become more important. Older BAS didn’t have this capability or it was not understood and not used. Recently this proved to be a valuable tool in determining the problem of water treatment usage, or lack thereof, in a condenser water system. The inconsistencies in the water treatment for this system led to premature cooling tower failure. Being able to monitor the system and see the trends of water usage helped us understand the problem and determine the solution.
Sheerin: We have a sophisticated bedside interface at the Nemours Children’s Hospital that provides control of the “mood” lighting (patient selectable covelight color) along with the window shade and nurse call, Get Well network, and a host of other things. Making it all come together and ultimately work together has required our team, a lot of different vendors, and the owner to work very hard. In a recent IMRIS Neurosurgery Suite, we worked as the integrator to ensure that the connectivity and mapping of the more than 45 systems in that suite came together properly. That was a very technology-dense project.