Considerations for designing plumbing

systems in health care facilities

Legionella and scald prevention top plumbing trends in health care settings.

By Nicole Krawcke

Polypropylene piping was recently used at Bozeman, Montana Health Hospital for the cooling system water, chilled water and condenser water, as well as some domestic water. The installing contractor’s general superintendent, Tom Harmon of Williams Plumbing, explained: “With any piping system, careful system design and proper operation are keys to help ensure successful outcomes and trouble-free performance for the end-user.”

Plumbing and HVAC systems inside health care facilities tend to be much more complex than your everyday run of the mill commercial building. Hospitals and other medical facilities have unique systems not found elsewhere, including medical gas, dialysis systems, emergency showers and eyewashes as well as clean rooms, such as laboratories and operating rooms. It tends to reason that there are many considerations engineers must think about when it comes to designing plumbing systems in health care applications.

“The most critical consideration in designing plumbing systems in health care facilities is patient and staff safety,” notes James Paschal, P.E., LEED AP, chief technology officer for Aquatherm. “The delivery of clean and safe potable water is paramount, and accounting for all the design elements necessary to do that is crucial. Ensuring clean and safe potable water includes using materials that will not impart contaminants into the water as well as a system design that delivers water at safe temperatures and essentially free of harmful bacteria.”  

Another critical consideration in the proper design of plumbing systems in health care facilities involves Legionella prevention, according to Chip O’Neil, vice president of research and development for Reliance Worldwide Corp. (RWC).

AQT Supplied Healthcare Cooling Twr

As the industry gets a better understanding of how harmful bacteria such as Legionella can proliferate in some areas of plumbing systems, it becomes increasingly clear that these systems need to be properly designed, maintained and operated regardless of the piping material.

“Legionella is a potentially deadly human health hazard when it grows in poorly designed or poorly maintained water systems, such as domestic water, industrial water and cooling towers,” he says. “Other particularly important considerations include prevention of scalding and thermal shock, as well as cross-connection control and prevention.”

Patient rooms and bathrooms must also be given careful consideration. Adrien Scherer, manager of commercial health care sales for Oatey Co., suggests engineers take a systems approach when specifying shower solutions.

“When it comes to shower systems, specifying a complete shower solution is the best way to ensure efficiency and effective drainage,” he says. “For example, a system that includes an integrated drain, pre-sloped shower pan and topical sheet or liquid waterproofing accessories. Additionally, when specifying shower plumbing systems, keep the system functionality in mind. For example, it's important to find a shower solution in health care applications that works for curbless showers, accommodating universal designs following the Americans with Disabilities Act (ADA).”

Scherer notes customization and flexibility are equally important factors as well.

“When working with existing plumbing systems, you never know what you might run into on-site,” he says. “Whether during a new build, renovation, threshold or a back-wall installation, contractors will encounter various plumbing and fixture layout conditions. Therefore, I suggest specifying a solution that allows contractors to adapt to unexpected plumbing rough-in configurations and different shower enclosure sizes.”

Fixture, Wood
HoldRite copper brackets are installed in White Plains Hospital in White Plains, New York.

HoldRite copper brackets are installed in White Plains Hospital in White Plains, New York.

Plumbing trends

Zach Rohlfs, senior associate, plumbing and fire protection for Boston-based BR+A Consulting Engineers notes that waterborne pathogens — especially Legionella — are a big deal in health care market.

“It all comes down to the fact we have lower flow rates now for fixtures,” he explains. “IAPMO is in the process of updating fixture sizes because there’s been this big push for water use reduction. The biggest problem with that is while water usage has been reduced, a change in pipe sizes hasn’t really been considered — there’s been no real change in the size of plumbing pipes. These old flow rates were higher, but now we have to contend with lower flow rates going through the same size pipe. So the water is moving slower through the pipe, and it’s longer to change it over. Bacteria needs time to grow and something to grow in. So with that longer change over period, you’re giving bacteria somewhere to grow as well as time to grow. And if you’re a person with a pool, you know chlorine dissipates over time. So the disinfectant goes away.”

Rohlfs acknowledges modifications to the Hunter’s Curve have helped address this issue some, but it still doesn’t account for everything.

Along with Legionella, scald prevention is the other most pressing trend in designing plumbing systems for health care facilities, and the two challenges can be tightly intertwined, Paschal points out.

“One of the more conventional means of controlling Legionella is raising the operating temperatures of the systems; but doing that can increase the risk of scalding patients or staff, and in some cases, can have adverse effects on piping systems components,” he explains. “Also, for this method to succeed, the water temperature needs to be raised throughout the entire system.

“Many facility operators also use chemical means of preventing the Legionella bacteria, such as hyper/super chlorination, chlorine dioxide, monochloramines and copper-silver ion generation,” Paschal continues. “These measures, as well as ultraviolet (UV) light, have differing levels of effectiveness as well as potential side effects. While these measures may be used in a health care facility once a plumbing system is installed and operating, plumbing system designers need to consider Legionella and scald-prevention measures at the planning and design stage.”

Tile flooring, Material property, Rectangle, Wood, Floor

A QuickDrain ProLine linear drain is used at major Cleveland hospital.

Paschal notes that proper design, maintenance and operation of the plumbing system is the best way to prevent a Legionella outbreak: “There is no piping material that can prevent Legionella.”

O’Neil points to several trends in health care plumbing systems currently impacting the market, including: centralized building automation systems; central thermostatic mixing control stations with Internet of Things (IoT) capability and monitoring; thermal balancing of water systems; elimination of “dead legs,” which, if not addressed properly, allow for stagnation within a facility’s piping systems; systems designed to be capable of undergoing thermal disinfection regularly, easily and predictably; systems designed with the use of building information modeling (BIM) techniques; and plumbing systems that are integrated with audio alarms tied to centralized building automation systems.

“All of these trends are driven by the relentless demand for safe and high-quality health care that keeps up with the latest technologies and capabilities as innovation marches on,” O’Neil says.

Overall, easier maintenance and overall style are the two trends influencing plumbing system design in health care facilities, Scherer says.

“Installers are trying to shoot for a better aesthetic overall, avoiding the cookie-cutter specification of every hospital bathroom or shower looking the same,” he explains. “Especially in health care applications, building owners try to get away from the all-to-common institutional look and feel. ADA-compliant bathrooms and showers don’t need to look institutional. We're seeing it a lot in senior living and assisted living. Architects and engineers want the bathroom to look and feel like you're at home, not at a hospital, to accomplishing a warmer feel instead of the usual institutional feel.”


ADA-compliant showers need not look institutional because of drain options that disappear into the wall, such as QuickDrain's WallDrain.

Scherer notes these trends are driven by a health care market that is trying to modernize, and has, of course, been impacted by the current landscape around the world.

“Specifically, in health care, the pandemic changed the construction of these facilities,” he says. “There's a demand for enhanced cleanliness and more effective maintenance, so hospital management can turn over the rooms faster and get them completely sanitized for the next patient. Ease of maintenance within bathrooms for hospitals is crucial. So, specifying antimicrobial and/or self-cleaning materials is an important part of plumbing system design in the health care space.”

Linear drains offer lower maintenance when integrated with larger format tiles, reducing the number of grout joints and seams where mold, mildew and grime can grow.

“Nobody in a hospital has the time to go in and clean every individual grout line,” Scherer says. “If we can cut down their number, it makes it a lot easier to maintain and keep clean.”

Considerations for medical gas

NFPA 99: “Health Care Facilities Code” was first published in 1984. Since then, the document has evolved to establish the minimum requirements within all health care facilities for performance, maintenance and testing of electrical systems. Current issues such as climate change and the global pandemic dramatically reinforce the importance of resiliency and reliability within all types of health care facilities. The latest version of NFPA 99 addresses these latest issues, and a few others.

According to Brian O’Connor, P.E., engineer with National Fire Protection Association (NFPA), the major changes to the 2021 edition of NFPA 99 include:

  1. A new section on “Responsible Facility Authority,” which compiles and clearly states the responsibilities and qualifications of this newly created designation. A majority of the responsibilities this person has have been requirements in NFPA 99 for some time, but this new section requires a single point of responsibility to be created;
  2. A new section on the development of a “Permit to Work System,” which requires a permit to be pulled when any work is done on the health care facility. This ensures that there are no surprise interruptions in service or changes that deviate from the code occur;
  3. A new section and definitions related to using health care microgrids as a power source;
  4. When clinical spaces are converted to nonclinical spaces (for example a doctor’s office turning into a waiting room), the medical gas/vacuum inlets/outlets that are not accessible for maintenance and testing need to be removed or decommissioned;
  5. The emergency oxygen supply connection now requires an alarm to be installed to monitor the supply so you won’t be surprised when the temporary supply gets low; and
  6. The definition “Home Care” has been altered to better clarify what is considered home care (and thus not covered by NFPA 99).

“There are several purposes behind these changes, the first it is to keep improving upon the previous editions of the code by finding deficiencies in it and correcting or improving those,” O’Connor says. “Second is to keep up with changing technologies, such as health care microgrids. Third is to improve upon the operational requirements, such as the development of the permit to work system and the advent of the responsible facility authority. It is very important to use the most up to date codes and standards in order to prevent the loss of life and property damage in health care facilities.”


Because WallDrain is built into the wall instead of the floor surface, it offers a totally concealed and sleek look, Oatey notes.

Considerations for a post-COVID-19 world

According to O’Connor, while the pandemic has changed many things, it has not changed the factors engineers should consider when designing health care facilities.

“Preventing fires, preventing electrical shock, allowing for safe egress, avoiding inadvertent cross connections of medical gas and vacuum systems as well as infection control are all among the top things an engineer must consider when designing a health care facility,” he says.

Rohlfs notes the only real change he sees following the pandemic is a greater importance placed on medical gas.

“During the pandemic, there were issues with oxygen and questions on whether facilities could handle extra ventilators on the medical air side,” he says. “Additionally, I think people are handwashing more instead of relying solely on hand sanitizer. Engineers should just make sure they are designing to reduce the risk of waterborne pathogens the best they can, because the bacteria is there.”

Paschal notes that ensuring plumbing systems have as few dead legs as possible is crucial in the current environment.

“Those dead legs, or areas where water is not circulating, can harbor Legionella, and may be a source for other bacteria or viruses, such as COVID-19,” he says. “It is also worth noting that COVID-19 has not been detected in properly disinfected potable water supplies. The systems — especially the hot water systems — need to be designed so that water is circulating all the way up to the fixtures. As we, as an industry, get a better understanding of how harmful bacteria such as Legionella can proliferate in some areas of the plumbing systems, it becomes increasingly clear that these systems need to be properly designed, maintained and operated.”

Quick Drain Mt Carmel Proline

Dearborn Safety Series ADA Compliant Lavatory Tubular Covers are made from antimicrobial and UV-resistant material.

Scherer again stresses the systems-based approach, as well as taking into account the ability to adapt to jobsite conditions and specifications, whether it be for a renovation or new construction. Additionally, specifying materials that are aesthetically pleasing and easy to maintain are key.

“The healthcare industry is rapidly growing, making it vital to stay up-to-date on technology and products to ensure top-quality care,” he says. “No two construction projects are the same. With that being said, the demands and requirements of a health care project are even more unique. These projects entail innovative solutions and an expert team to make sure the project is completed on time, within budget and built to rigorous specifications.”

Engineers should relentlessly focus on specifying materials and systems that are easily maintained over time, while avoiding those that are resistant to various disinfectant methods, O’Neil suggests.

“Health care facilities are a critical element of our society and will continue to become even more important as we face pandemics and an ever-aging population,” he says. “With that in mind, it becomes increasingly important that designers and engineers are mindful of specifying and insisting upon materials, systems and equipment that provide resiliency over the long haul. This includes the use of equipment, materials and methods that enable healthcare facilities to provide uninterrupted service, despite less-than-ideal situations, such as overcrowding, over-use, extreme weather events and natural disasters.”

Nicole Krawcke, is chief editor of PM Engineer.

PM Engineer Archive