Comparison of CFD and Multizone Modeling from Contaminant Migration from a Household Gas Furnace

Abstract

In Central and Eastern Europe, a growing popularity of gas heaters as the main source of heat and domestic hot water can be observed. This is the result of new laws and strategies for funding that have been put in place to encourage households to stop using coal and replace it with cleaner energy sources. However, there is a growing concern that gas furnaces are prone to malfunction and can be a threat to occupants through CO (carbon monoxide) generation. To see how a faulty gas furnace with a clogged exhaust may affect a household, a series of multizone and computational fluid dynamics (CFD) simulations were carried out using the CONTAM software and CFD0 editor created by the National Institute of Standards and Technology (NIST). The simulations presented different placements of the furnace and ventilation outlet in an attached garage. The results showed how the placement influenced contaminant migration and occupant exposure to CO. It changed the amount of CO that infiltrated to the attached house and influenced occupant exposure. The results may be used by future users to minimize the risk of CO poisoning by using the proper natural ventilation methods together with optimal placement of the header in the household.

Investigation of Airflow Distribution and Contamination Control with Different Schemes in an Operating Room

“…Figure 1 displays the HVAC system in the operating room, (a) filter in air handling unit (AHU) system to filter dirty air coming from the mixing air cabin, (b) cooling coil to cool down the temperature of the air with chilled water on the coil that comes from the process of cooling the water by the chiller, (c) heating coil for the process of heating and humidifying the air to fit with the design of the operating room, (d) fan to supply the air into the room, (e) HEPA filter to filter the air particles with the efficiency of HEPA filters over 99.97% (above 0.5 µm) so that the air entering the room becomes clean, (f) return air; the air coming from the room draughts to the AHU system and supplies the operating room. [18]. The results revealed that the location of the furnace could influence contaminant accumulation and migration.…”

“…The improvement in indoor air quality (IAQ) was also conducted by the measurement and CFD simulations that are shown as valid tools for IAQ indication [17]. In addition, CFD modeling of contaminant migration in a household gas furnace was investigated by Szczepanik-Scislo [18]. The results revealed that the location of the furnace could influence contaminant accumulation and migration.…”

Improving Household Safety via a Dynamic Air Terminal Device in Order to Decrease Carbon Monoxide Migration from a Gas Furnace

“…A previous study showed that accumulation of CO in a garage also elevated the levels of CO inside an attached household and that ventilation strategies have a large effect on the contaminant migration [19]. However, in this previous study, only natural ventilation was used.…”

“…Because of its potential to quickly impact human health and even endanger human life, it was taken as a priority out of the contaminants that would occur in such a scenario. In a previous study, it was shown that a faulty exhaust line from the furnace not only resulted in a rise in CO in the room where the furnace was installed, but also in the adjoining building [19]. According to the World Health Organization (WHO), a person should not be subjected to a concentration of CO higher than 30 ppm (0.000055) in 1 h or 9 ppm (0.000017 kg/kg) during a period of 8 h [41].…”

“…The test zone was a garage with a faulty furnace, like in the previous study [19]. The chosen CFD zone was the garage and its layout on the CFD0 software can be seen in Figure 1.…”