As hotels age or experience lower occupancy levels, building systems — especially water technologies — must meet the need for greater flexibility.

Hotels, like any structure built with the expectation of frequent use and occupancy, must provide guests and travelers the assurance of consistently maintained services, including the provision of safe, healthy domestic water service free of pathogens.

These are very real risks, with solutions that can’t be taken for granted. I know of many instances, especially at older urban hotels, where plumbing systems were expanded and altered to meet changing needs — whether for expansion or modernization. It’s not a rare occurrence for facility managers to later learn of the existence of carelessly isolated plumbing dead legs. 

This can happen when plumbing retrofit work isn’t performed with care. It’s in these dead legs that water can stagnate, serving as nurseries for bacteria growth. 

Another challenge for any hotel without modern domestic water temperature and pressure regulation is to maintain storage and distribution temperatures in such a way as to keep guests safe from the risks of Legionella growth or scalding at faucets and showerheads. 

However, there are technologies available today, with relatively quick alterations, to solve a wide range of problems associated with hotel domestic water systems. 

Pandemic + fuel prices

Following two years of risk and uncertainty, we’re only now moving beyond the shocking effects of the COVID-19 pandemic. It’s no surprise that hotels have struggled under the effect of greatly reduced travel.

Similar to any machine, a hotel’s many moving parts need routine use, care and maintenance. That includes water heating, treatment and filtration; maintenance of safe storage and distribution temperatures; and water circulation. Without these, facility managers and maintenance personnel must make a concerted effort to keep hotel water systems safe and clean. 

U.S. Department of Transportation data reveals that, through much of 2020 and 2021, domestic travel was reduced by 60 percent or more, and international travel by more than 70 percent. That inconsistency dealt a wicked blow to some already weakened, older hotel plumbing systems, particularly those relying on a steady stream of income to preserve reliable maintenance and upgrades. 

Further, with hotel water piping systems sized to meet the full occupation of rooms, lower-than-average hotel capacity can create more problems. “Water age” is a term now being used to describe the amount of time water spends idle within the piping system of a building. 

Large-diameter pipe serving few water fixtures not only means the water will spend more time in a domestic water system, but also lower the velocity inside the pipe — both of which have the potential to allow water to stagnate. 

Digital mixing

At hotels and motels — more so than at most commercial facilities — this challenge is magnified by the number of guest rooms. It can be a substantial challenge for facility managers and maintenance staff because the range of problems with older domestic water systems often persist through all but one true solution: digital mixing. 

Older domestic water systems were good, but not good enough. As those systems aged or sat idle for weeks or months, the “perfect storm” for facility managers and system engineers forms as:

• Users become less tolerant of long waits for hot water.

• Inexact temperature deliveries result in scalding risks.

• Maintenance staff has a greater awareness of the risks of Legionella bacteria in systems with fewer protective measures in place.

It’s an unfortunate reality, in the wake of COVID-19, that managers of some upscale hotels with four- and five-star ratings must admit they can’t assure customers they’ll have a warm shower when they want it. Or germ-free shower water. 

Airport hotel woes

The director of engineering at a Midwest Marriott hotel lamented stressful challenges with the facility’s domestic water pressure and temperature. 

According to the engineer, late arrivers and early risers often pushed the limits of a hotel’s water heaters and plumbing systems. At the nearly-400-room hotel, near a busy airport, a steady flow of guests occurred at all hours. 

“The highest demand for hot water comes between 5 a.m. and 6 a.m., and again between 10 p.m. and midnight,” he says. It wasn’t uncommon for hotel managers to get several calls a week from guests displeased with the lack of hot water. 

“Unfortunately,” he adds, “the best we could tell them at the time was that hot water was ‘on its way.’”

For years, the hotel battled domestic hot water issues. As it turns out, an incorrectly installed mechanical valve had a 120-second response time and couldn’t actuate with sufficient speed to keep up with the hotel’s routinely fluctuating water pressures. 

Because of the valve’s sluggish response time, every time something would go wrong with the pumps, heat exchangers or storage tanks, the entire DHW system would require a time-consuming recalibration. Maintenance was required frequently and became a constant source of disruption for the engineering staff. 

“More or less, when maintaining the domestic water system, we had to isolate the entire piped network, shutting it down completely,” the engineer explains. “Whenever the hot water mixing valve opened or modulated, the entire system would flood with cold water.”

Enough is enough

Eventually, hotel managers decided to replace the entire hot water system. They called a local plumbing and mechanical installation firm specializing in commercial and industrial work. 

“The owner of the company and I had this discussion about the hotel’s domestic water system,” the facility engineer says. “A key challenge was the presence of so many dynamic changes with the pumps and water pressures. We knew what the hotel needed was a smarter, more responsive valve — especially considering that guests in all the hundreds of rooms had very different schedules.” 

Hotel managers chose against another Band-Aid approach, selecting instead a smart delivery solution for mixing domestic water in a hot water recirculation loop: a Powers IntelliStation digital mixing system from Watts. The digital mixing solution features an intuitive touch screen display. Its modular construction also makes repair and maintenance quick and easy. 

Yet, to be sure, hotel managers first visited another hotel with similar hot water issues. There, they’d installed an IntelliStation digital mixing system, allowing the Marriott facility engineer to see the technology in operation and speak to facility managers who eagerly vouched for the system.

Digital water mixing represents a significant leap in the technology used to control hot water delivery. The approach incorporates a programmable valve to quickly process temperature (mixed outlet +/- 2 degrees to set point), flow and pressure data, which is obtained from the hot and cold water inlets, mixed outlet and sensors on the mixed-water return. 

High-speed, responsive electronic actuation modulates a simple valve that allows the set point to be electronically controlled and maintained. An integral recirculation pump can be programmed to turn on/off to a target set point and temperature variance. 

Digital mixing allows engineers or facility managers to select a desired hot water temperature and to control and monitor entire water distribution systems. 

Bruce Fathers is the senior product manager, Watts Water Quality.