Biofilms lead to energy-intensive operations, says Fresh-Aire UV

Florida, USA, 20 August 2018: Growing emphasis on energy efficiency has driven demand for the use of UV to irradiate the cooling coils in HVAC applications. Stuart Engel, International Business Development, Fresh-Aire UV, shared this observation gleaning from the company’s profile of activities, stressing that design engineers have seen payback of maintaining the cleanliness of coils and ensuring they are not blocked by growth of biofilms, which are often fed by cold, wet and damp environments. “The result of biofilm growing on the coils is an increased pressure drop across the coils, which results in increased energy that is required to move the air and will keep increasing as the biofilm grows,” Engel explained. “Without UV installed on the coils, chemicals and pressure washing must be used to remove the biofilm, which is expensive, time- and labour-intensive and has many environmental issues.” Once the coils are blocked, Engel said, it is extremely difficult to clean the centre of the coil as pressure washing pushes the biofilm and further compacts it. This, he said, is where UV offers an environmentally safe and economical solution to keep coils clean. “Depending on the cost of electricity, installing UV on cooling coils can save between 15 and 25% of the annual HVAC energy cost and virtually eliminate having to manually clean the coils,” he said. “Payback time for installing UV will depend in part on the cost of power, annual operating and cooling hours and will normally be between two and 11 months.” Emphasising ease of installation, Engel added that installing UV on HVAC cooling coils will increase the life of the coils. Depending on the amount of biofilm present on the coil however, Engel said it may take as long as two months for the UV to penetrate and break down the biofilm and restore the airflow to design specifications.   Hannah Jo Uy is Assistant Editor at Climate Control Middle East magazine. She may be contacted at hannah@cpi-industry.com