Which of the following appliances would typically require a flue gas vent?

A gas furnace requires a flue gas vent because it operates by burning natural gas or propane to produce heat. During this process, combustion gases are generated, which can include carbon monoxide and other harmful substances. To ensure safety and proper operation, these gases must be vented outside the home, thus necessitating the installation of a flue gas vent.

In contrast, electric heaters, induction cooktops, and heat pumps do not involve combustion processes. Electric heaters and induction cooktops operate using electric energy to generate heat without producing flue gases, while heat pumps transfer heat rather than generate it through combustion. Therefore, these appliances do not require a venting system to manage combustion byproducts, making the gas furnace the appliance that specifically requires a flue gas vent.