What is the primary function of a gas-fired appliance draft diverter or draft hood?

What is the primary function of a gas-fired appliance draft diverter or draft hood?

• A. To balance combustion air and prevent negative draft from pulling combustion products back into the living space.
• B. To create drafts to speed venting
• C. To filter exhaust gases
• D. To cool the flue gases

Answer: (A)

A draft hood or draft diverter is there to keep combustion products moving safely up the vent while preventing those gases from entering the living space when the house experiences changes in air pressure. It provides a controlled path for the flue gases to escape and allows a little room for outdoor air to dilute and balance the vent flow, so negative house pressure or cross-drafts don’t pull combustion products back inside. This protects occupants and the living space from backdrafting. It isn’t meant to create drafts to speed venting, filter exhaust gases, or cool the flue gases, which is why the other options don’t fit.

A draft hood or draft diverter is there to keep combustion products moving safely up the vent while preventing those gases from entering the living space when the house experiences changes in air pressure. It provides a controlled path for the flue gases to escape and allows a little room for outdoor air to dilute and balance the vent flow, so negative house pressure or cross-drafts don’t pull combustion products back inside. This protects occupants and the living space from backdrafting.

It isn’t meant to create drafts to speed venting, filter exhaust gases, or cool the flue gases, which is why the other options don’t fit.