When schools and universities look at saving energy in their facilities, they are likely to review the efficiency of their heating and cooling systems, or the quality of their building envelopes.
When facility managers focus attention on school bathrooms, they are more likely to consider issues such as cleanliness and safety as more critical than energy conservation. But education institutions can provide students and staff members with bathrooms that are more energy-efficient, as well as safe and sanitary.
If everyone who used the bathrooms at education facilities were conscientious about using water wisely, waste wouldn't be an issue for schools and universities. But because many users either aren't aware of or don't care about the environmental or financial benefits of cutting down on water use, facility managers have sought out equipment that reduces the use of water without the assistance of users.
Low-flow toilets, as the name implies, use significantly less water than older models: 1.6 gallons per flush or less, compared with 3.5 gallons or more. Dual-flush toilets have two settings, so less water is used for liquid waste than for solid waste.
Bathroom faucets and locker-room showers can be equipped with aerators or other low-flow devices that reduce the amount of water being used. “Electric eye” motion sensors installed on faucets can turn off a faucet automatically if a school doesn't want to take the chance that a user will leave the water running.
Hundreds of students using multiple bathrooms at thousands of schools at least a couple of times a day for 180 days a year: the gallons of water that could be saved could fill a lake.
In a guide for K-12 schools, the Alliance for Water Efficiency notes that proper maintenance is critical for much of the water-saving equipment to perform as promised.
“To retain water savings, building maintenance staff must be trained to use only the proper parts when servicing the flush valves,” the Alliance says. “Unfortunately, 3.5 gallons-per-flush parts often fit the new 1.6 gallons-per-flush valves.”
The Alliance also advises schools not to install sensors on toilets to trigger automatic flushing.
“Sensor flush mechanisms often result in more frequent toilet flushing than manual flush valves,” the Alliance says. “There is no evidence the sensor valves save water.”
For schools and universities looking to reduce water consumption, urinals that use no water clearly will accomplish that goal. No-water urinals use chemical drain traps that allow urine to pass through while preventing odors from escaping.
Conservation advocates estimate that one no-water urinal can save as much as 45,000 gallons of water a year. However, schools that install no-water urinals have to be diligent about maintaining the units and changing the drain traps when necessary.
If the urinals are not installed or maintained correctly, or if users dump other liquids into the urinals, a bathroom could be plagued with an odor problem.
Some schools have decided to forgo no-water urinals because of the additional maintenance and other drawbacks. In recent construction projects, California Polytechnic State University in San Luis Obispo has specified ultra-low-flow urinals (0.125 gallons per flush), which it says provides 90 percent of the water savings that no-water urinals provide, but without the additional maintenance of traps and seals.
Paper or air
Good hygiene habits require students and staff to wash their hands before leaving a school bathroom. And that means bathrooms have to provide a way for users to dry their hands. Several factors can affect the drying method that an education institution chooses: user preference, cleanliness, reliability and energy consumption.
In most homes, people use cloth towels to dry their hands. Continuous-cloth towels are no longer as common as they once were in public bathrooms. Compared with alternatives, they use less energy because they don't need electricity and, unlike paper towels, the cloth towels can be cleaned and reused. But unless a school has enough staff to change and launder the towels frequently, hand washers may find they have to wipe their hands on their pants legs if they don't want to dry themselves with a damp and dirty towel at the end of its roll.
Institutions with public bathrooms typically choose between paper towels and air dryers. At first glance, it seems that each method has pros and cons in terms of energy use. Air dryers consume electricity to provide the burst of hot air that dries hands, and manufacturing the units themselves consumes energy. Paper towel dispensers consume little or no electricity, but the paper towels themselves consume energy at several steps along the way: cutting down trees, converting wood to paper, transporting it to bathrooms, disposing of it after it's been used, and recycling it or taking it to a landfill.
Research seeking to determine which method is better for the environment has not settled the debate, but many studies have concluded that using air dryers results in less energy consumption, especially with the growing availability of models that dry hands more quickly and expend energy more efficiently.
Educational institutions also can cut energy consumption in bathrooms by replacing any incandescent lights with more efficient compact fluorescent bulbs. Using daylighting strategies for bathrooms that have windows or controlling lights with timers or motion sensors will enable a school to have the lights on only when someone is inside a bathroom.
- Read the "Going with the (low) flow" sidebar to learn how Harvard University made its bathrooms more efficient.
Kennedy, staff writer, can be reached at [email protected].
Going with the (low) flow
Harvard University has made many of its bathrooms more efficient in the last year by installing new sinks and toilets that use less water.
The university's Faculty of Arts and Sciences, which oversees Harvard College, the Graduate School of Arts and Sciences, the School of Engineering and Applied Sciences, and the Division of Continuing Education, has put in 900 new low-flow sinks and 675 dual-flush toilets.
Aerators on the sinks reduce water flow to 0.5 gallons of water per minute compared with 2.2 or 2.0 gallons per minute used by the old sinks. That is a 75 to 77 percent drop in water use, the university says.
Dual-flush toilets use different amounts of water to flush waste. The units installed at Harvard use 1.1 gallons when a user pulls the handle up to flush liquid waste, and 1.6 gallons when a user pulls the handle down to flush solid waste.
Similar upgrades have taken place in the university's residence halls and libraries.