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PROJECT
plumbing
School Goes Tankless, Saves $70k Annually Replacing a 2,300-gal. electric water heater with a tankless system resulted in a two-month ROI and significant annual energy savings.
Because the wait time for hot water could be substantial in a large school facility, one of the tankless water heaters is on a recirculation system, which moves hot water in a loop close to fixtures, so there is less of a hot-water wait. The new tankless water heaters also feature unit redundancy, which means that if one, two, or more units require maintenance, the remaining units seamlessly continue to provide on-demand hot-water service to the school. Therefore, even if one unit shuts down, the system still operates with approximately 80% to 90% coverage. “Redundancy was another major reason the school decided to go with a tankless system,” said Palmer. “If one unit wasn’t working or needed maintenance, the school would still have hot water. You could just work on the unit that needed to be worked on without shut-
L
ocated in Overton County, Livingston Acade-
more effective that new system would be at meeting
my High School in Livingston, TN, is a public
the school’s hot water needs and reducing energy costs.
The whole project took about six months, includ-
school with approximately 900 students. Op-
In fact, throughout 2012, the school saved $65,000 to
ing specifying equipment, developing a plan, and
erating the school’s 1970s electric water heater had
$70,000 in energy costs as a result of installing a Rin-
completing installation during summer vacation.
been draining the school’s funds for a while. It was
nai tankless water-heating system. Rinnai America
“Once we had everything figured out, it went very
time for a change.
Corp. is located in Peachtree City, GA.
fast,” said Palmer. “Rinnai experts helped us specify
ting down the hot-water supply.”
In 2011, the school took steps to replace the old
The school’s maintenance staff began working with
the right number of units for the school’s hot-water
water heater with a more efficient water-heating solu-
Jim Palmer, territory sales manager for C.C. Dickson
demands. They gave us good advice and direction and
tion. What wasn’t known at the time was how much
Co., Wilson, NC, one of the largest wholesale distrib-
what they recommended is providing fantastic results.”
utors of HVAC/R equipment in the Southeast, to design a new, more energy-efficient system.
“We never imagined how much money it would save,” said Palmer. “The system paid for itself in two
Palmer had seen the benefits of tankless water heat-
months. The school is still amazed at how well the new
ers in other applications, but had not yet been involved
system is working—that something that compact could
with such a project. After much consideration, Palmer
deliver the hot water they need. They have no com-
and school administrators collectively decided that
plaints. Not one.”
Rinnai Ultra Series condensing tankless water heaters
Overton County School System decisionmakers
would offer the school optimal energy savings and ef-
are planning to gradually switch to Rinnai condensing
fectively meet its hot-water needs.
tankless water heaters in all schools. Additionally,
Removal of the older, 2,300-gal. electric water-heat-
when the Overton County Sheriff ’s Department
er tank from the school’s mechanical room proved to
heard about the energy savings experienced at Living-
be a challenge. “The old tank was the size of a car. It
ston Academy, it contacted Palmer for information.
took up half the room and we had to cut it at the bolt
“We are looking for more and more opportunities to
forces to get it out the door. The tankless units are only
use tankless water heaters. People see the value of them
one-third the size and are a much more powerful sys-
and the results speak for themselves,” Palmer said. CBP
tem. It’s quite impressive,” said Palmer. The project’s team worked with Rinnai engineering in the design and installation of a sophisticated rack system
DATA CACHE
for the mechanical room. Collectively, the school needed seven Rinnai condensing tankless units—approximately 1.4 million Btu—to adequately supply hot water to its five mop sinks, 75 regular sinks, and 46 showers. Each unit is individually vented through the building’s roof. An existing gas line in the mechanical room allowed the team to Top. When the Livingston Academy school replaced its 2,300-gal. electric water heater with a tankless system, the school realized a $70,000 annual energy savings. Above. The seven tankless units have a 1.7-million-Btu capacity and the system paid for itself in two months.
easily make the switch from electric to gas. Condensing units were selected because they capture latent heat before it escapes into the vent system and transfer it to the water being heated. This improves energy efficiency. Condensing units offer an energy factor rating as high as 0.95, compared with 0.82 with non-condensing tankless units.
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COMMERCI A L BUIL DING P RODUC T S
APRIL 2014
www.cbpmagazine.com
Want more information? The resources below are linked in our digital magazine at cbpmagazine.com/digital/apr2014.
Circle 10 on the Reader Service Card. Evaluate the specifications of the Rinnai RU98 unit at http://www. rinnai.us/commercial/tankless-products/ru98i-reu-kb3237ffud-us. Download the RU98 spec sheet at http://www.rinnai.us/ documentation/downloads/RU98i_KB3237FFUD_spec_sheet_ tankless_water_heater.pdf. Download a manual for designing tankless-water-heating systems at http://www.rinnai.us/documentation/downloads/R-TRWH-E-02_ Rev_D.pdf.
