Maintaining Student Performance

In Austin, Texas, school building maintenance, including the maintenance of mechanical systems, forms part of the educational program.

“Anything that helps the school building perform properly helps students perform better as students,” says Alan Albers, executive director of operations and facilities with the Round Rock Independent School District in Austin. “We want the buildings and the building systems to work perfectly. We don’t want an uncomfortable building to become a topic of discussion.”

Albers’ facility team takes care of a lot of buildings. Round Rock spans 110 square miles and 46 campuses. It includes four high schools, eight middle schools, 31 elementary schools and a variety of administrative facilities. Just over 42,000 students attend school in the district.

Albers team of heating, ventilating and air-conditioning (HVAC) technicians start early, well before the school day begins. First thing every morning, they gather at the energy management office, hop online with laptop computers and check out the schools. Each takes care of certain schools and buildings. Each taps into sensors that monitor HVAC operations from air temperatures to compressor running times to system diagnostics.

They check e-mail for after-hours requests for air conditioning, heating and lighting from faculty and administrators. They might respond to requests by adjusting the air conditioning and lighting in various areas to accommodate after school activities.

“We’ve gone beyond pipe wrenches,” Albers says. “We can completely check out the HVAC systems in each building every day before school starts. The diagnostic capabilities in the building control system will even send e-mail about a component of the system that has varied from its optimal operating characteristics and requires service.

Complementing the early morning systems checks, Albers is also assigning maintenance crews to night shifts, when systems can be shut down and maintained without inconveniencing students, faculty or administrators. “We’re doing this not just for mechanical systems but across the board,” Albers says. “We’re beefing up preventive maintenance on anything with moving parts by doing it at night.”

Goals of Mechanical System Maintenance
For Albers, mechanical systems maintenance seeks three goals. First, as noted earlier, the mechanical systems create and sustain a comfortable indoor environment.

Second, the equipment is enormously expensive. Round Rock schools use boilers ranging in size from 120 gallons to 400 gallons; they cost from $28,000 to $45,000. The chillers range from 125-ton to 350-ton capacities and cost between $75,000 and $500,000.

The capital cost of such equipment on 46 campuses probably runs to several million dollars. “We want this equipment to last 25 years,” Albers says. “If you don’t take care of it, it will wear out in just 12 to 15 years.”

Shortening the life of capital equipment by half effectively doubles the cost of that equipment.

Third and last, poorly maintained equipment uses more energy to produce the same level of environmental comfort, thus raising utility costs.

Anything short of competent maintenance costs the district money that could be better used in the classrooms.

Send in the Coupons
Manuel Castillo, Round Rock’s HVAC supervisor, focuses on preventing pipe corrosion, scaling and bacterial growth in the network of tubes inside chillers. “We monitor for that with coupons,” he says.

Coupons? Coupons are small pieces of copper steel and other metals, chosen because they corrode easily.  Third-party water treatment experts treat the water running through chiller tubes monthly with chemicals designed to prevent the tubes from corroding and scaling. Coupons help determine whether or not the treatments are working. Every 90 days, Castillo removes the coupons and analyzes them to ensure that the water treatment is doing what it is supposed to do. It’s an early warning system that enables him to spot and deal with trends before they become problems.

Basic Maintenance
Water-cooled chillers reside inside buildings, with large companion cooling towers placed outside. Together, the two pieces of equipment form an open system, a system exposed to outside air and contaminants. “Inside a cooling tower, a sump collects water at the bottom of the unit,” says Pete Jefferson, PE, LEED-AP, HBDP, a principal and vice president with the M.E. Group/design + green, a Denver-based architectural firm. “The water is typically out in the open and exposed to the elements. Rainwater, leaves, dirt and other contaminants can get into the unit. So you have to treat the water to prevent the contaminants from causing scaling and corrosion.”

Most districts employ water treatment companies to do this work on chillers, cooling towers and boilers. These companies test the pH level of the water and look for corrosive agents and minerals that will create deposits or scales inside the plumbing, continues Jefferson. They treat the water with chemicals dealing with problems turned up in the analysis.

“Despite the water treatments, contaminates eventually build up in the basins and heat exchangers and cause scaling,” says Steve Klestinec, Round Rock’s director of maintenance. “Hot water heaters scale up, too; as do large boilers. To extend the life of this equipment, you have to treat the water monthly and clean them out a couple times of year.”

In the Round Rock district, six schools have large chillers and companion cooling towers. Klestinec says it costs approximately $75,000 per year to treat the water and to clean out these pieces of equipment. The district also spends $25,000 to $30,000 per year to maintain and clean the hot water heater on the districts’ 46 campuses. Both the chillers and cooling towers receive a thorough inspection and cleaning once a year.

“The water treatments hold down the cost of cleaning,” continues Klestinec. “Without the treatments, we would have to clean the equipment every couple of weeks, doubling and tripling the costs. The equipment would use more energy, too.”

Albers recalls a time when a neighboring school district dealt with a third party water treatment company that did a poor job. “The tubes in the boiler broke and put the unit out of commission,” he says. “I’ve seen the same issue with chillers — the tubes get corroded and cannot exchange heat. At that point, you have to rebuild the equipment, or, if that can’t be done, replace it.”

Another basic maintenance task involves protecting the separation between the domestic water system and the water flowing through the water heaters, boilers, chillers and cooling towers. “There is a point where the domestic water system feeds the mechanical system,” explains Mike Wolfe, the district’s supervisor of plumbing.  “At that point, you have to prevent any contaminating backflow from the mechanical side into the domestic water source should the pressure in the domestic system decline for any reason.

“That requires a device approved by Uniform Plumbing Code. We regularly test our device and turn the results into the city.”

People Watching
Albers’ maintenance strategy includes paying close attention to the health of the students, faculty and administrators that use district buildings. “People are sensitive to HVAC problems today,” he says. “If a student gets a sniffle, it might be something in the system.

“We respond aggressively to any complaints like this. We also monitor the absentee rate and talk regularly with the school nurse about health complaints she may be receiving.”

An environmental technician evaluates any and all complaints that might tie into the indoor air quality of any Round Rock building. The buildings rarely turn out to be at fault — because Albers’ approach to mechanical system maintenance begins and ends with the idea that the buildings are for the students. Building characteristics that interfere with their ability to learn is a maintenance problem.