We should replace the single high-level HasFlueOrChimneyInConditionedSpace input with defaulting on the individual building components (e.g., water heater, heating system). For example, default the Furnace/AtmosphericBurner element based on fuel type and efficiency, then determine if there's a flue in conditioned space by looking at individual components' properties.
When making this change, we should also update related waterheater.rb code (like this) to use it.