Gabrielle has just upgraded her oil-burning furnace to a Forced air system.
A furnace is a place where combustion takes place. In a furnace, it is normal to burn a carbonaceous material and produce energy in the process.
The type of furnace that takes cool air from outside and passes it through the heat source using a fan or blower is a Forced air system. Hence, Gabrielle has just upgraded her oil-burning furnace to a Forced air system.
Learn more about Forced air system:https://brainly.com/question/14530969
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