“The boilers were oversized for the school,” said Hugh Leahy, project manager for the Boston office of Siemens Building Technologies, the company hired as the mechanical designers and general contractor for the project.
“One of the boilers ran all year long, the other stayed in stand-by mode. When it was time to replace them, the school district really wanted to make sure they installed an efficient boiler.”
In fact, the ultimate goal of the project was to help the school district to save money by cutting their energy consumption and fuel costs.
Siemens specified four, high efficiency, Smith 28 HE, 12-section cast iron boilers for the project, due in part to their thermal efficiency rating of up to 85 percent. As part of the project the new boilers were brought into the facility in sections and assembled on location in the boiler room. New concrete pads were poured for the new Smith 28 HE boilers, and the existing heating infrastructure was re-used. The only new piping required was from the new boilers to the header. Tucker Mechanical of Meriden, Connecticut installed the new system.
Cast iron sections are precision-machined to ensure dimensional accuracy. In addition, graphite port connectors provide the installation ease of a gasket and the longevity of a push nipple to minimize call-backs. The graphite connectors provide a lifetime seal that is impervious to chemicals, flue gases and high temperatures.The Smith Series 28 HE boilers -- available in 15 basic sizes with output ratings from 931 to 4,622 MBH - are designed to provide the highest combustion and thermal efficiencies possible with forced draft firing. They can be used in either water or steam systems, and may be fired with light oil, gas or gas/oil combination.
One of the primary objectives for the project was to help the school district to save money. And according to Leahy, the estimated fuel savings was nearly 25%. Perhaps more important, the school never had to run more than three boilers at any given time all year, so there is still plenty of heating capacity.
Read the attached .pdf document for more information.