An in-house HVAC team used a multi-split system to bring affordable air conditioning to the gymnasium of a 50-year old school. The plan worked, with cooling results better than anticipated
Administrators in school districts across the U.S. are finding it difficult to obtain funding for capital improvements. Tax levies don’t always pass easily, the population of many cities has declined, and unemployment is high.
However, the Jackson County Board of Education, Jefferson, GA, isn’t letting reduced funding hold it back from making some necessary equipment upgrades. It’s just careful to spend wisely the money that it obtains from an existing, special purpose local option sales tax (SPLOST).
The Jackson County School District operates 14 schools, and administrators have realized that each of the schools will soon need new air conditioning. Indeed, some of those schools— such as the North Jackson Elementary School —a 50-year-old building — were built without air conditioning. This school’s classrooms and administrative offices were air conditioned in 1984.
The North Jackson Elementary School gym, which wasn’t air conditioned, is a metal-framed structure with a full-size basketball court, offices, and restrooms. In addition to daily classes, most school functions such as assemblies, graduations, and general meetings, are also held in the space.
With school now starting in early August, the gymnasium’s high temperature would present health and comfort issues for children, teachers, and parents. Installing a traditional air conditioning system in the gymnasium would have involved a package unit on the ground and fabricated ductwork running up the side of the building, through the gymnasium wall, and across the entire ceiling. The primary issue with this standard application was its associated cost against existing funds. It was estimated that it would have cost $15,000 to convert the school’s 225-amp single-phase electric service to three-phase in order to meet the needs of two, 15-ton package units. Necessary ductwork was estimated at another $15,000, and associated equipment costs were close to $24,000. At a price tag of nearly $54,000, the project was not likely to gain Board of Education approval.
Josh Patton has been the HVAC foreman for the Jackson County Board of Education for 12 years. Prior to starting this position, he worked for a local HVAC contractor. His objective was to provide a cost-effective solution, budget-wise and operationally, for this first-generation air conditioning installation.
As someone in tune with comfort technology, Patton was aware of what could be done using a mini-split system. He had used one such system, an LG unit, for a kitchen conversion in June of 2011. There, he used LG Multi-F products to provide supplemental cooling in the cafeteria space as a cost-effective alternative to adding ductwork.
“I wanted something we could do in-house, because we have 10 of these gyms that are identical, with no air conditioning,” he explains.
In partnership with the local LG representative, Terry Friesenda, Patton proposed a design that would meet the gymnasium’s cooling requirements based on load calculations, within Board of Education budget restrictions. The resulting system — installed by Patton, and his technicians, Karl Odom, and Tim Love — included eight indoor units around the perimeter of the gym discharging air towards the center, and three ceiling cassettes in the center of the gym discharging air in a four-way pattern.
The 11 indoor evaporator units and seven outdoor units operate independently of each other and provide load-matching capability far beyond a single system using a single thermostat. The project was completed in three weeks.
Continue to Next Page: Reduced Electricity, Gas Costs
Reduced Electricity, Gas Costs
Each of the LMU369 systems are rated at 15.8 SEER at full load. The systems were installed on the existing electric service, effectively eliminating the costs associated with an electric service upgrade. Additionally, the LG inverter systems allowed Jackson County Schools to remove natural gas fueled space heaters, and the associated cost.
As an extra wattage and cost saver, Patton addressed the power draw by the gymnasium’s old 400 Watt metal halide light fixtures. He replaced them with more efficient lighting, and cut one third of the amps per leg, from 76 to 22 amps. ”That gave me enough power to run the LG units without further changes,” he explains.
During a graduation ceremony in May 2012, the gym was able to maintain set point (68F) with nearly 400 people present.
“I had hoped we could maintain 78-80F, and can’t believe how well the system performed under these conditions,” Patton says. “By using inverter systems, we’re able to individually control the seven systems with independent set points. By nature of the operation, they match the Btuh load as called for.”
Using the LG technology enabled Patton and the team to stay within budget, and to beat their estimates for the conversion. In addition, Georgia Power provided a rebate for using the high-efficiency systems to further offset the costs. “I saved more than $20,000 by using the LG systems on this job, before we even factor in operating savings,” Patton adds.
The total cooling load need was estimated at 31 tons, but Patton says the inverter units are maintaining comfort with only 22.5 tons of cooling.
One final advantage: physical education classes could continue during the installation, though in somewhat reduced areas, as the ceiling units were installed one at a time.And now, when the school bell rings at North Jackson
elementary, phys-ed might be everyone’s favorite class, thanks to the vastly improved comfort of new air conditioning.