Which device is used to provide dilution air to the vent system of a gas water heater?

Which device is used to provide dilution air to the vent system of a gas water heater?

• A. Vent Cap
• B. Air Inlet Damper
• C. Draft Hood
• D. Draft Regulator

Answer: (C)

Providing dilution air to the vent system is necessary so that the combustion gases can mix with room air as they exit, helping to stabilize the draft and prevent backdrafting in a natural-draft vent. The device that accomplishes this for a gas water heater is the draft hood. It sits on top of the combustion area and provides an opening for room air to enter the vent path, diluting the flue gases before they rise up the vent. This keeps venting safe and reliable even when room conditions or wind affect the draft. The other devices have different roles: a vent cap protects the vent outlet from rain and pests; an air inlet damper regulates air into a combustion zone but isn’t for dilution in the vent; a draft regulator controls the draft strength but doesn’t supply dilution air.

Providing dilution air to the vent system is necessary so that the combustion gases can mix with room air as they exit, helping to stabilize the draft and prevent backdrafting in a natural-draft vent. The device that accomplishes this for a gas water heater is the draft hood. It sits on top of the combustion area and provides an opening for room air to enter the vent path, diluting the flue gases before they rise up the vent. This keeps venting safe and reliable even when room conditions or wind affect the draft. The other devices have different roles: a vent cap protects the vent outlet from rain and pests; an air inlet damper regulates air into a combustion zone but isn’t for dilution in the vent; a draft regulator controls the draft strength but doesn’t supply dilution air.