Risk Assessment of Household Gas Heaters in Tehran During an Earthquake Crisis by Using the Fuzzy FMEA Model

Background: A variety of gas heaters are used in residential, administrative, and commercial buildings in Iran. Home packages (HP) and central heating boiler rooms (CHBRs) are among the most common types of heating systems that can be damaged during earthquakes and, thus, harm the building and the residents. Methods: By doing a survey and an interview in 50 residential buildings in District 16 of Tehran, the risks of these facilities were assessed during earthquakes from the viewpoint of the residents. To do the risk assessment, the failure mode and effects analysis (FMEA) model in the fuzzy space were applied. To analyze the risk priority number (RPN), defuzzification and the center of gravity method were used. Based on the results, 11 indicators were identified and evaluated for each system. Results: The mean RPNs obtained for both systems were almost equal (the difference was about 2%). Thus, no definitive superiority can be presumed for HP or CHBR when earthquakes happen. The major difference in the risk of each system can be separately evaluated based on the conditions of each building, confidence about the quality of installation, connections, pipe materials, electric wire corrosion, etc. Conclusion: It is suggested that the risks of CHBR and HP during earthquakes are the same, and some issues such as design, economy, and technical issues play a greater role in contractors’ selection of the system.