Developing an Electrical System toward the Prevention of Heat Ventilation Air Conditioning Contamination

Abstract

Biofilms comprise diverse bacteria and fungi with slime material, especially in humid conditions. The surface of the heat ventilation and air conditioning (HVAC) system, especially at the evaporator, is in high moisture conditions due to the compression and relaxation of refrigerant. Biofilms comprise electrically polarized molecules, which include polysaccharide, DNA, liposome, and diverse amino acids. Thus, when an electric field is applied to biofilms, the field creates an electrostatic force that enhances the destruction of biofilms and results in detachment from the surface. The principles are known as the bioelectric effect. A new bioelectric (BE) technology has been developed that is focused on the optimization of electrical energy for biofilm removal, and its efficacy has been previously demonstrated. In this work, a prototype of the BE device for HVAC application has been fabricated and tested. Escherichia coli (E. coli) biofilms were utilized as a standard model of biofilm on the HVAC evaporator. The results demonstrate that when the BE technology was applied for one hour, approximately 81.8% of total biofilm was removed. Furthermore, live cells in biofilms were reduced by approximately 71.4% under the BE device, compared to non-treated biofilms.