Gas Venting Types

Non-Mechanical

• Uses the density difference between hot exhaust & cooler ambient air
• Negative vent pressure

Atmospheric Vent

• Most common venting style, also known as “Chimney Vent”
• Uses surrounding air for combustion and exhausts through the flue
• Vents with B-vent or lined chimney
• Must use a draft diverter

Direct Vent

• Uses outside air for combustion and exhausts to the outside (concentric vent) (pipe within a pipe)
• Vent goes out the wall not through the ceiling
• Does not require any power (standing pilot)

Mechanical

• Uses a powered blower to expel exhaust gases through the vent system
• Positive vent pressure

Power Vent

• Uses inside air for combustion and vents either horizontally or vertically using PVC, CPVC, or ABS material
• Uses 1 pipe for venting the exhaust
• Requires power to vent exhaust (blower motor assembly)

Power Direct Vent

• Uses a twin pipe system, pulling air from the outside for combustion and venting exhaust to the outside with a separate pipe (sometimes concentric)
• Typically installed in applications where there is a lack of combustible air
• Requires power for intake and exhaust (blower motor assembly)