Designing, retrofitting hospitals during COVID: HVAC and plumbing
While COVID-19 has changed many aspects of HVAC systems in a health care facility, some things remain identical
- Luis Alvarez Colon, PE, Associate, Page, Austin, Texas
- Allison Graves, PE, Principal, RTM Engineering Consultants, Chicago
- Jeff Hankin, PE, LEED AP, Senior Principal, Stantec, San Diego
- Reed Paitich, PE, Associate, Wold Architects and Engineers, Saint Paul, Minn.
- Keith D. Prata, PE, LEED AP BD+C, Mechanical Department Manager, Bala Consulting Engineers, Boston
- Donald R. Stevens, CHFM, CHC, Director – Health Care Facilities, Lockwood Andrews & Newnam Inc. (LAN), Austin, Texas
What is the most challenging thing when designing HVAC systems in such buildings?
Allison Graves: The most challenging thing in designing mechanical, electrical and plumbing systems for health care buildings involves the amount of space available for the systems. Trying to fit a fully ducted HVAC system in the same ceiling as plumbing, medical gas, electrical and lighting systems and low-voltage cables is a constant challenge.
Keith D. Prata: I believe the greatest challenge is finding enough physical space inside the facility to house all of the required/needed mechanical, electrical and plumbing devices, equipment and pathways. This is particularly challenging when renovating existing buildings. Every device and pathway have a direct impact on the program area of the facility.
How have you and your team addressed the unique air requirements of COVID-19?
Donald R. Stevens: So far, it’s a lot of discussion with a few air cleaning products being installed at the suggestion of the manufacturers. UV lights and ionizing filters for example. Some owners are arbitrarily increasing the amount of outside air in their buildings. The guidelines from the various agencies are still in flux and it’s difficult to know which modifications can be made that will be sound investments in both human safety and capital expenditures.
Allison Graves: Our team has paid particular interest in the control of airflow in our recent designs. Being able to manage the pressurization of spaces and direct airflow in a path which matches the care givers procedures has been instrumental in making both the health care workers and patients feel safer in this confusing time.
What type of specialty piping, plumbing or other systems have you specified recently? Describe the project.
Reed Paitich: We recently upgraded an aging central utility plant as part of a hospital renovation project. The old equipment was centrally located in the basement but was landlocked in terms of getting piping infrastructure to different areas of the campus. We built a stand-alone central utility plant and connected it to the hospital via a bridge, with piping running across the bridge over to the existing roof. Due to the existing building structural weight limitations, we had to reduce the weight of the heating and chilled water piping, so we worked with the contractor to specify polypropylene piping mains on the roof.
Medical gases are vital for hospitals and medical campuses. Define the project, its goals, the challenges and the design solutions.
Reed Paitich: During the COVID-19 pandemic, we have had multiple clients inquire about their installed bulk oxygen system. One client was concerned about how long their bulk oxygen system could sustain the entire med surg department if it was completely full of patients needing oxygen, while keeping the emergency department functional. Since our firm keeps as-built documents in our main office, we were able to calculate potential oxygen flow at each outlet within the two departments simultaneously and show they have adequate capacity in their existing system, particularly that their main line from the bulk tank to the hospital was adequately sized.
What unusual or infrequently specified products or systems did you use to meet challenging heating or cooling needs?
Allison Graves: For a recent renovation project we specified MaxiTherm Heat Exhangers for the replacement of the hospital’s heating system. By specifying this equipment, we were able to take the heating system off the low-pressure steam system, eliminating the need for replacement of the pressure-reducing valve station. We connected the new heat exchanges directly into the 125 psi main steam lines. This will allow the facility to provide routine maintenance on their low-pressure steam systems without needing to shut all heat off to the building. The elimination of pressure-reducing valves and smaller line sizes along with the packaged controls from the manufacturer also made the installation more cost effective than a traditional heat exchanger system.
How have you worked with HVAC system or equipment design to increase a building’s energy efficiency?
Allison Graves: Much of the newer equipment is already designed to meet the stringent efficiency requirements set forth in the energy codes. What we tend to do is find unique ways of applying the equipment into an overall system. For example, by using three MaxiTherm Flooded Vertical heat exchangers, we are able to eliminate the flash steam and draw just a little more heat out of the system. Increasing overall system efficiency ever so much.
What systems are you putting in place to combat hospital acquired infections (HAI)?
Allison Graves: Secure Aire is an electronic filtration product that we have recently installed in a large existing air-handling system. Adding any extra level of help in capturing and filtering small particles allows for the overall air quality within the facility be better for the occupants.