Healthy hospital success: Sustainability
With hospital projects, it is imperative that engineers get everything exactly right—after all, the lives of patients treated in the health care building may depend on it. Sustainability, energy efficiency, and intelligent buildings are discussed.
Richard Heim, PE, LEED AP, Mechanical Project Engineer, RMF Engineering Inc., Baltimore
Tim Koch, PE, LEED AP, Electrical Engineer, HDR Inc., Omaha, Neb.
Nolan Rome, PE, LEED AP, Senior Vice President, ccrd, a WSP | Parsons Brinckerhoff Co., Phoenix
Raymond Schultz, PE, Project Engineer, CannonDesign, Grand Island, N.Y.
Kunal G. Shah, PE, LEED AP, RCDD, President, PBS Engineers, Glendora, Calif.
Tommy Spears, PE, Vice President of Design Solutions, TME, Little Rock, Ark.
CSE: Energy efficiency and sustainability are often a request from building owners. What net zero energy and/or high-performance systems have you recently specified on a hospital?
Rome: We have recently employed heat pump chillers and group-source heat pump technologies to reduce the energy footprint of our hospital designs. A hospital is one of the few building programs with simultaneous heating and cooling loads in all seasons, allowing us to harvest the heat being removed and use it for reheating and to produce hot water, thus reducing the cost of utilities and achieving both natural gas and domestic water make-up savings by not using cooling towers to reject heat. We have not yet designed a net zero hospital, but we are using PVs and solar water heating on a hospital project that is the closest thing to net zero energy that we have done.
Spears: We often specify high-performance systems for the majority of our health care projects, including heat pump chiller heaters, advanced building automation controls, and sequences of operation to reduce overall energy consumption. However, even though the design is intended to be high-performing, it doesn’t always function that way once the facility is in operation. On a recent project for a hospital in Florida, TME provided commissioning services after the high-performance design was completed but did not meet the Energy Star goal of 75 that was set by the owner. After TME was engaged and implemented several zero-capital improvement projects, the Energy Star rating increased to a 97, making it one of the most efficient facilities in the nation.
Koch: Most of the hospital projects we have designed in the last several years have implemented or evaluated the implementation of a heat-recovery chiller system. Hospitals are an ideal application for a heat-recovery chiller due to the airflow air-change requirements in rooms and the need to reheat this air in interior spaces while requiring cooler supply air for exterior spaces. Hospitals also operate 24 hours a day, which increases the payback. These systems are especially beneficial if there is a year-round cooling requirement such as a main data center in the hospital.
Shah: There is a growing trend to explore the feasibility of net zero; however, for a hospital function it is very difficult to achieve. The consumption level is very high, which makes it difficult to produce that high of energy to offset. Our team has done numerous studies and provided options to help achieve net zero energy for office-building and commercial function. Implementing HVAC strategies and on-site renewable energy systems are the foundations to developing an appropriate system.
Heim: RMF recently specified magnetic-bearing (frictionless) chillers in a hospital central plant. The chillers have an excellent part-load efficiency, which is often where the central plant is operating. The downside is that they are extremely sensitive. There was certainly a learning curve, but after adjusting several setpoints, we have seen the energy benefits of the system. Building owners have often requested energy wheels on AHUs, which due to the frequent high requirements of OA in hospitals allow another opportunity for energy savings.
CSE: Many aspects of sustainability (power, HVAC, maintenance, etc.) require building personnel to follow certain practices to be effective. What, if anything, can an engineer do to help increase chances of success in this area?
Heim: I find it important to provide training and a vision of the system intent to those who will operate and maintain it. Walking through the sequence of operations and explaining why the system operates as it does is extremely valuable to the building staff. Just as important is providing potential typical scenarios (such as failure of a specific piece of equipment) and what should happen to the building system during these events. If building personnel understand these aspects of the system, they are better prepared to operate and maintain the system efficiently.
Rome: Our company is proactive about having the facility engineering staff involved early in the design process, and works to keep them engaged through the process so that the systems are at a sophistication level that staff is comfortable with and can maintain. Once we turn a building over, it becomes a living system and having buy-in from the staff is crucial to reaching the planned efficiencies.
Shah: To be successful in this area, the engineer must implement a process that starts at design, and is not a milestone at the end of the project. Engaging the end users and understanding their process and method of operation helps to develop a design that meets the operational requirements and fits within their process. The system operation must be documented fully and simplified as much as it technically can to outline the key operational processes to maintain the sustainable integrity of the system.
Spears: TME’s approach to this process involves including the facility management staff early on in the design and commissioning processes, a practice recommended in the ASHE Health Facility Commissioning Handbook. When maintenance staff are involved in design, the engineer often benefits from an operations and maintenance (O&M) point of view that may affect the way certain spaces are laid out to ensure that the staff can maintain the building once construction is complete. We also follow a transition to operations process during commissioning that brings O&M personnel in to witness functional performance tests and sequence programming, so they understand the why and how behind certain aspects of facility operation. Additionally, we recommend and provide a benchmarking assessment for facility staff, as well as training tailored to address any deficiencies in certain areas.
CSE: Please share a hospital success story in which you were able to enhance sustainability of an existing building. Annual statistics on energy savings and other supporting evidence would be helpful.
Rome: We designed a replacement of a campus central energy plant and an addition to a new high-rise tower for Phoenix Children’s Hospital. The existing hospital was performing at close to 360 Btuh/sq ft. Phoenix Children’s early on stated they wanted a high-performing plant and building, but they wanted an SS Camero and not a Corvette. We worked with Johnson Controls, which is the plant service provider, to design a heat pump chiller system and convert the campus from steam to heating hot water to maximize the advantage of the simultaneous heating and cooling loads. The existing hospital was back-fed and served by the new heat pump chiller plant a full year early and showed a reduced energy consumption to 260 Btuh/sq ft from the new plant service. The total campus consumption today, including the new 12-story tower, is running at approximately 175 Btuh/sq ft and improving through retro-commissioning efforts in the existing building as part of an ongoing partnership.
Koch: HDR worked closely with health care partners to develop a clinical interface that integrates HIPPA-compliant, real-time patient information with the building management system, providing positive feedback when an OR is occupied or unoccupied. When the room is unoccupied, the air-exchange rate is reduced to code minimum while maintaining differential pressure, temperature, and humidity. The clinical interface assists the hospital in meeting the meaningful-use requirements of the American Hospital Association and saves the hospital an average of $5,500/OR annually (example: $55,000/year for 10 ORs). Per actual data, the OR is occupied less than 20% for 10 mo of the year, and less than 40% for the remaining 2 mo. The user interface is embraced by the infection-control clinicians by providing confirmation the environment parameters are within code. Installations have been running successfully since 2012.
Spears: TME provided retro-commissioning services for Sacred Heart Hospital on the Gulf, a 64,323-sq-ft facility in Port St. Joe, Fla. The retro-commissioning process included revisions to all major systems and setpoints, a room ventilation schedule, central plant programming revisions, and M&V to ensure savings and performance improvements. TME provided BAS remote monitoring to troubleshoot any problems as well as identify additional cost-reduction opportunities. The hospital invested a total of $61,000 in retro-commissioning costs. After implementing the recommended energy cost-reduction measures, savings for this project exceeds $150,000 annually, resulting in a less than a 5-mo payback on services performed, and the facility’s Energy Star Rating increased from 1 to 59.
CSE: Please describe your experience in smart or intelligent hospitals.
Koch: Similar to IoT, an integrable base for all building systems is necessary to provide readable data where and when it is needed. The real question is what comes first, the integrable base or the actual integration applications that provide a desired outcome. Since integration applications usually go through multiple iterations before they go mainstream or are used for reliable data, the infrastructure is necessary for testing and development. However, spending resources on data interfaces for "nice-to-have" applications may not be available. These are the decisions we go through with many owners. A second question needs to be addressed: "Who does the owner call when an integration fails to operate?" Having trained personnel or the ability to making only one phone call for the resolution leads to a sustainable (and reliable) integration.
Spears: A large portion of smart design in hospitals is related to patient comfort. Amenities like temperature and light controls at each bed as well as entertainment packages, Internet access, and the ability to look up medical records and hospital bills from patient rooms are becoming more commonplace. As hospitals become more dependent on paperless data and records, they also require more infrastructure and bandwidth to support those systems. Additionally, in several of our current and recent projects, TME is implementing measures that allow the BAS to control all functions of the hospital. By importing communications directly to the BAS from each system, the hospital saves on wiring and material costs; and while the programming and testing costs are higher at the onset of these projects, there is an overall reduction in maintenance and failure points that saves facilities time and money in the long run.
Rome: We are designing most of our current hospital control systems to use control algorithms that "learn" from the data collected. Additionally, we are integrating the lighting and patient-usage systems into the BAS so that we setback unoccupied rooms automatically, but still maintain pressure relationships, etc.