Elemental Composition Analysis of Air‐Side Fouling of a Unitary Room Air Conditioning System Using FESEM With EDX

With an emphasis on both indoor and outdoor settings, this study examines the elemental composition of fouling material collected from air conditioners in Cebu City, Philippines. Key elements were found using an energy‐dispersive X‐ray spectroscopy (EDX) study, including calcium (Ca), iron (Fe), potassium (K), silicon (Si), and aluminum (Al). Al (3.3 wt. %) and Si (7.3 wt. %) were more abundant in indoor samples, but Ca (6.9 wt. %) and Mg (4.9 wt. %) were more abundant in outdoor samples. Significant regional differences in K, Ca, and Fe concentrations were found by statistical analysis using ANOVA ( p < 0.05), highlighting the impact of operational and environmental factors on fouling formation. The findings shed light on how local environmental factors affect the buildup of fouling material. Additionally, as part of the goal of this study, the elemental composition of dust determined serves as a basis for creating standard test dust for assessing prospect fouling‐resistant coatings for heat exchangers of an air conditioning system. This work can contribute to AC maintenance optimization and advance coating technology, especially in tropical climates with high fouling issues.