Effects of HVAC on combustion-gas transport in residential structures. (March 2022)

• Record Type: Journal Article
• Authors: Ghanekar, Shruti; Weinschenk, Craig; Horn, Gavin P.; Stakes, Keith; Kesler, Richard M.; Lee, Tonghun
• Is Part Of: Fire safety journal. Volume 128(2022)
• Publication Date: 2022-03
• Subjects: Gas transport -- Water vapor -- Compartment fires -- Gas burners -- HVAC; Fire prevention -- Periodicals; Incendies -- Prévention -- Recherche -- Périodiques; Fire prevention -- Research; Periodicals; 628.92205
• DOI: 10.1016/j.firesaf.2022.103534
• Languages: English
• ISSNs: 0379-7112

Abstract

Abstract: Time-resolved concentrations of oxygen (O2 ), carbon dioxide (CO2 ) and water vapor (H2 O) produced by controlled propane gas burners are measured at three locations in a residential structure equipped with a heating, ventilation and air-conditioning (HVAC) system. Experiments are conducted to assess the effects of HVAC operating status (off vs. on) and the impact of bedroom door position (open vs. closed) on species concentrations. Change in concentration up to the flame extinction point, the rate of change, and the transport time for the measured species at each location is compared. The CO2 –O2 concentration ratio derived from these experiments correlates strongly with the stoichiometric combustion ratio. The CO2 –H2 O and O2 –H2 O ratios have a relatively strong correlation though with slightly higher variability. Both the HVAC status and bedroom door position have statistically significant influence on the total change in concentration for all the measured species. However, HVAC status only has a statistically significant effect on the rate of change of H2 O but not CO2 and O2 concentrations. For all three species in both bedrooms, the concentrations typically begin to change later in experiments with HVAC off than experiments with HVAC on. Highlights: O2, CO2 and water vapor are measured in full-scale residential structures. Impact of HVAC operating status and bedroom door position on concentrations studied. HVAC status and door position have statistically significant impact on total change. Door position has statistically significant impact on rate of change. Gas concentrations change later with HVAC off than with HVAC on.