What does induced draft mean in furnace operation?

What does induced draft mean in furnace operation?

• A. The combustion airflow is artificially created.
• B. The combustion airflow relies on natural draft rather than a fan.
• C. It eliminates the need for a heat exchanger.
• D. It cools exhaust before it leaves the vent.

Answer: (A)

Induced draft means a mechanical inducer (a fan) is used to create the airflow for venting combustion gases. This blower pulls the combustion products through the heat exchanger and out the vent, producing negative pressure in the furnace to ensure proper venting and prevent backdrafts. That’s different from natural draft, which relies on buoyancy and a chimney to move gases without a fan. The heat exchanger is still needed to transfer heat and separate combustion products; the purpose isn’t to cool exhaust.

Induced draft means a mechanical inducer (a fan) is used to create the airflow for venting combustion gases. This blower pulls the combustion products through the heat exchanger and out the vent, producing negative pressure in the furnace to ensure proper venting and prevent backdrafts. That’s different from natural draft, which relies on buoyancy and a chimney to move gases without a fan. The heat exchanger is still needed to transfer heat and separate combustion products; the purpose isn’t to cool exhaust.