Where should a draft control device be installed if the manufacturer does not specify the location?

• A. On the floor near the equipment
• B. In the attic
• C. On the roof
• D. Attached to the flue collar of the equipment or as near to the equipment as practical

Answer: (D)

Draft control devices must sense the actual draft coming from the appliance to regulate venting safely. Placing the device on the flue collar or as close to the equipment as practical puts the sensing element directly in the exhaust path, ensuring an accurate reading of stack pressure and a quick, appropriate response to changes in combustion or vent conditions.

If the device were installed on the floor near the equipment, in the attic, or on the roof, it would be exposed to ambient air and conditions far removed from the actual vent outlet. This could lead to inaccurate readings, delayed responses, or vulnerability to weather, condensation, and serviceability issues. Therefore, the closest and most reliable placement is on the flue collar or as near to the equipment as possible.