Children at the Will Rogers Elementary school in Hobbs, New Mexico, situated close by the Texas border in the southeastern part of the Land of Enchantment state, are enjoying a new heating and cooling system this school year, thanks to a Taco LoadMatch® hydronic system installed during the summer of 2006.
The Will Rogers School, named for the cowboy humorist and actor, was built in the late 1930s and is considered a historical building in the city of Hobbs, a community of almost 29,000 residents. When an addition to the original building was added in the 1970s, air conditioning was installed to offset the 100° F daytime summer temperatures. Except for the addition of the chilled water system and routine maintenance over the years, the school's original HVAC system functioned until it was replaced in 2006.
Will Rogers Elementary School. The school, constructed in the late 1930s, underwent a renovation of its heating and cooling system in 2006.
For the Will Rogers project, like similar LoadMatch projects in recent years, engineers and contractors encountered the innovative Loadmatch system for the first time. In this case the LoadMatch system was introduced to Alegro Engineering of El Paso, Texas, the consulting engineering firm on the project, by Taco's local sales representative firm of Massey Johnson, also of El Paso. Robert Johnson, a partner at Massey Johnson, has installed a LoadMatch system in his new home so he knew the system and its benefits firsthand. He brought the LoadMatch system concept and its attendant Hydronic System Solutions (HSS) software system design program to the attention of Rolando Legarreta, a project manager at Alegro Engineering.
Alegro liked the HSS software, especially its graphic interface with AutoCad. "Once you get the hang of it," says Legarreta, "it makes total system design so much easier." Engineers like HSS because it allows them to design LoadMatch-equipped commercial systems in less time and with a higher degree of accuracy. With its system design accounting ability, HSS automatically performs engineering calculations and design tasks that engineers previously labored over manually, like head loss and static pressure calculations.
Taco KV vertical pumps in the school's mechanical room.
Alegro Engineering brought the LoadMatch system design for the Will Rogers school retrofit to Israel Franco, part of the contractor team, for review. Franco and his group were skeptical at first of the Loadmatch single pipe concept, and knew that school department officials had asked for a conventional four-pipe system for the project. Franco also knew that municipal clients tended to shy away from innovative systems like LoadMatch.
Though they had their reservations, Franco's team took a close look at the LoadMatch system, reviewing it top to bottom for functionality and reliability. "We studied the concept and its applications, and we looked at some other LoadMatch installations," says Israel Franco. "We keep an open mind regarding new technology."
Key to the final selection of the LoadMatch system was its ability to meet design and budget requirements. The contractor was convinced that a LoadMatch system for the school could meet its budget and serve as a best first-cost option.
Twin Loadmatch circulators attached to an IEC fan coil in school's attic.
Taco maintains that LoadMatch provides better comfort than DX air systems as well as four-pipe hydronic systems. A LoadMatch system is self-balancing, and it eliminates the need for most balancing valves and expensive, energy consuming control valves, replacing them with small, energy efficient LoadMatch circulators in this case attached to 53 fan coils supplied by IEC.
LoadMatch's circulators direct water in the system to where it needs to go, as opposed to forcing the water through a conventional system's long piping loop. With less pipe and valves needed, LoadMatch saves on materials. It is also highly energy efficient, requiring less horsepower to move BTUs around a building than an air system. Taco estimates that LoadMatch can achieve savings up to 30 percent of life cycle costs.
With the LoadMatch design approved, work on the school's HVAC retrofit began just as soon as school let out for the summer. A typical retrofit of this size can take from eight to twelve months but in the case of the Will Rogers School the job had to be completed by mid August. August 15th, in fact, was the project's so called "D-Day," when the fan coils and chillers had to demo'd. Although a challenge time-wise, the installation went smoothly and was completed on time.
Interior of Hobbs elementary school.
Along with the LoadMatch circulators and IEC fan coils, the school's new HVAC system consists of two RayPak boilers located just outside the school building. The school has an independent zone for a combined cafeteria and activities area serviced by a separate Raypak boiler, Taco KV vertical pumps, and a 30-ton Trane air handler. Trane chillers comprise the air conditioning system for the entire building. Honeywell temperature sensors were installed at several locations along the piping loop. Teachers and custodians can set Honeywell DDC controls in individual classrooms between 60° and 80° F for year-round comfort.
The cooling side of the HVAC system was commissioned first, in mid-August, just prior to the start of the new school year, and the heat side got its start-up in November 2006. On the day of the air conditioning start-up the outside temperature was 100° with about 50 percent humidity, according to Robert Johnson, forcing the cooling equipment through a good initial workout.