It was the middle of summer when the compressors in a Massachusetts facility shut down. Though the compressors had run smoothly for years, but no more; they were overheating in the midafternoon. The facility manager reached out to Atlas Copco to remedy the situation.
“The manager was not very happy,” said the Atlas Copco regional representative who worked with the facility. “For years they were happy with our compressors and preventative service plan. When things started to go wrong, all they saw was the problem and our logo on the compressors.”
The understandably upset facility manager had followed all the Atlas Copco recommendations, and had even installed cooling ductwork in the compressor room. Yet the compressors were still overheating.
“We quickly realized that the HVAC system was incorrect,” the Atlas Copco regional representative said. “The facility manager had it installed because the compressor room was getting hot in the summer. This is a great idea, but there was a small issue. We noticed it when we had trouble opening the door to access the compressor room.”
This clue was the gateway to solving the problem. When air is exhausted from a compressor room, more air should be introduced. If not, the room is starved of air and negative pressure is created.
“Once we got into the room, we immediately realized the issue wasn’t with the compressors, but with the airflow,” the Atlas Copco regional representative said. “There wasn’t any ‘make-up air’ coming into the space. We left the door and a few windows open, and the compressors started functioning better right away.”
The facility manager had the HVAC company install make-up air ductwork from the outside directly into each compressor inlet-air grating. While this is typically a recommended practice, it still didn’t solve the facility’s problem.
“You would think everything would be fine now, but the units continued to overheat,” the Atlas Copco regional representative said. “We came back out to the facility and inspected the system again. The ductwork inside the building looked fine but when we went outside we noticed that the hot air discharge was too close to the cooling air inlet. That allowed hot air to be drawn into the cooling air duct, causing a buildup of inlet air temperatures that eventually resulted in overheating.”
Atlas Copco recommended the facility run the hot air discharge ductwork away from the inlet cooling air duct in the summer but into the warehouse during the winter. The 50,000 square foot warehouse was kept at just above freezing during winter months to save money on heating costs. While this was fine for the product, employees had to dress for frigid temperatures.
“The customer was wary of this solution, because they weren’t convinced that the heat recovery would offset the cost of additional ductwork installation,” the Atlas Copco regional representative said.
The calculations proved otherwise. With four 350 horsepower compressors running fully loaded most of the time, the machines were producing over 3 million BTU/hr heat rejection.
Let’s put that in perspective. In order to heat a 2,500 square foot home in a winter climate (25 to 35 degrees Fahrenheit) to around 65 to 70 degrees Fahrenheit, you need approximately 125,000 BTU/hr. This means the 3 million BTU/hr produced by the compressors could heat more than 28 residential homes and easily heat the 50,000 square foot facility throughout the winter months.
The savings more than paid off.
“The customer was thrilled with the savings, and the employees were thrilled with the warmth,” the Atlas Copco regional representative said. “The installation went well, and the facility is still experiencing excellent compressor performance without the nuisance of high air temperature shut downs.”
On top of the energy savings the warehouse gained from using heat recovery, the utility company paid for 50 percent of the ductwork costs.
“This was truly a win for everyone,” the Atlas Copco regional representative said. “We were able to bring top quality service to our customer, the facility saved money and the employees can stay warm through the freezing Massachusetts winters.”
Do you have an Atlas Copco success story? Share it in the comments below! You can also view all of our customer stories by visiting www.atlascopco.com/air-usa.
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