In fact, the 64,000-sq.-ft. Cambridge, Md.-based plant had even sent workers home on several unbearable afternoons when interior temperatures surpassed 100∞F. Such work conditions and absenteeism typically result in reduced productivity and lower profits. “Other plants in this area have been faced with the same problems of absenteeism, lower productivity, and worker morale on hot summer days,” said Adam Xenides, project manager, Hi-Tech, a 15-year-old firm with 150 employees that produces 4 million injection molded tool handles annually in the plant. “We wanted to create a facility that supported our core business and added value back to the company — specifically through energy efficiency, customer satisfaction and operating cost per square foot.”
Typically hvac engineers remedy this common production plant problem with a chiller, air handler and metal ductwork that easily surpasses $1 million in equipment costs, not to mention exorbitant operating overheads. Mechanical engineer Smiley El-Abd, PE, G.F. Morin Co., had a better idea. Hi-Tech already had a chiller cooling its 18 plastic injection molded machines ranging in size from 200 to 1,800 tons in Plant 2. Since the chiller typically was used to only 60% of capacity, Hi-Tech engineers and El-Abd targeted the remaining chiller capacity to spot cool workers at its 100-sq.-ft. stations instead of cooling the entire plant.
While this method saved more than $350,000 over the purchase of a new dedicated chiller and piping to cool the plant, it was Hi-Tech and El-Abd’s innovations that made the project successful as well as energy efficient.
Metal ductwork was impractical not only due to high installation and material costs, but also because the metal building roof was already at its total load bearing capacity. Instead, fabric duct by FabricAir, Louisville, Ky., which is 90% lighter than metal duct, made the project possible because it didn’t affect the roof load.
Another factor making metal duct an inadequate solution for this project is its immovability. Like many plastics manufacturers, Hi-Tech sometimes move an injection molding machine into a different location throughout its production line, which may require the disassembling of duct lines. The two lines of fabric duct – a 292-ft. long (64-in. dia.) and 256-ft. long (52-in. dia.) run, however, can easily be unzipped, capped off, and relocated using the in-house plant maintenance staff.