Experimental analysis of air-handling unit fans’ failure on particulate matter concentrations due to incense burning in the south of Italy

Air-Handling Units are frequently operated under faulty conditions that may significantly affect concentrations of indoor pollutants and cause significant detrimental health issues for occupants. In this study the effects associated to the failure of the supply air fan (SAF) and the return air fan (RAF) in a typi-cal AHU on concentrations of air-borne fine particulate matters (PMs) due to burning of incense sticks are investigated via laboratory tests in the south of Italy. In particular, concentration-time data measured during both the faulty and fault free tests are compared in terms of concentration decay rate and particles removal efficiency. The analysis aimed at (i) experimentally charac-terizing the PM emissions of typical incense sticks, (ii) determining correla-tions representative of measured trends, and (ii) assessing the impacts of AHU fans’ failure on PM concentrations. The experimental data highlighted that the influence of the RAF failure is not really relevant, while the SAF failure significantly limits the AHU capability in reducing PM concentrations.