A fan-assisted appliance is considered to be what category?

A fan-assisted appliance is considered to be what category?

• A. Category One
• B. Category Two
• C. Category Three
• D. Not categorized

Answer: (A)

A fan-assisted appliance is categorized by how its venting system handles combustion products, specifically the pressure in the vent. Category I covers appliances that vent under atmospheric or nonpositive pressure—natural draft or with some mechanical aid that still results in the vent gas not being positively pressurized. Even though a fan helps move the exhaust, it doesn’t necessarily put the vent under positive pressure during normal operation. So the vent remains nonpositive, keeping the appliance in Category I. The other categories apply when the vent system operates under positive pressure (positive-pressure venting, direct-vent, or sealed-combustion setups with forced drafting), which isn’t the case for a typical fan-assisted appliance.

A fan-assisted appliance is categorized by how its venting system handles combustion products, specifically the pressure in the vent. Category I covers appliances that vent under atmospheric or nonpositive pressure—natural draft or with some mechanical aid that still results in the vent gas not being positively pressurized. Even though a fan helps move the exhaust, it doesn’t necessarily put the vent under positive pressure during normal operation. So the vent remains nonpositive, keeping the appliance in Category I. The other categories apply when the vent system operates under positive pressure (positive-pressure venting, direct-vent, or sealed-combustion setups with forced drafting), which isn’t the case for a typical fan-assisted appliance.