After cleaning the air conditioner coils at one of its campus buildings, Florida State University generated an additional 6.1 percent increase in air-flow, and the cooling coil showed a 10.5 percent increase in heat transfer. The cost of the coil cleaning was recouped in less than 10 months.
Rather than spending the money to replace the coils of its air conditioning unit at Dirac Science Library, Florida State decided to have the coils steam cleaned, according to Thomas Shewan, maintenance director at the university. Rejuvinair did the steam cleaning, and three years later had a case study on the project prepared by Performance Engineering Group (PEG).
Aaron Fancher, author of the PEG study, explained that it is regular practice for facility managers to replace the filters on building air conditioners, but more rare to clean the coils. “The filters are the first line of defense, but air can bypass the filters, so the coils get dirty in ways that are barely visible,” said Fancher. “We found after cleaning it improved the efficiency of the cooling and improved the efficiency of air flow.”
Dirty coils have higher resistance and require additional fan energy to maintain airflow. Also, dirty coils cause a loss of heat transfer, resulting in reduced cooling or heating efficiency.
At the Dirac Science Library, Rejuvinair steam cleaned the coils of the AHU‐21 Carrier model 39ED17, which was installed in 1985. Since the cleaning, the 7.5 horse power motor, which runs 24/7/365, is getting an the estimated fan energy savings of 4,200 Kwh or $420.00 annually. The combined air side and water side anticipated annual savings achieved from the steam sanitizing process is $2,686. The cost to achieve this efficiency was $2,200. This equates to a simple payback of less than 10 months.
While some companies use chemicals to clean air conditioning coils, Rejuvinair uses a chemical‐free, high-temperature, low-pressure steam cleaning and sanitizing process. “We have air conditioners that last five times longer,” said Richard Namovich, president and CEO of Rejuvinair. “When they get dirty the building can’t breath. But the coils could last forever.”