Combustion and Venting Principles Flashcards
6 cards from real G3 practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Combustion and Venting Principles flashcards as text
What is the primary purpose of a draft hood on a gas appliance?
Answer: To provide a safety break preventing excessive draft and backdraft
A draft hood prevents excessive updraft and protects against downdraft conditions.
What is a Category I venting system?
Answer: Negative pressure with non-condensing flue gases
Category I operates under negative pressure with flue gas above the dew point.
Why must vent connectors slope upward from appliance to chimney?
Answer: To ensure proper draft and prevent condensate pooling
Upward slope (minimum 1/4 inch per foot) maintains draft and prevents pooling.
What happens when flue gases cool below the dew point in a non-condensing vent?
Answer: Condensation forms, potentially causing corrosion and failure
Acidic condensation corrodes vent material and can cause premature failure.
What is the purpose of combustion air openings in a furnace room?
Answer: To supply oxygen for proper combustion and draft
Combustion air openings provide oxygen for combustion and draft operation.
What is spillage in a gas appliance vent system?
Answer: Flue gases escaping from the draft hood into the room
Spillage occurs when flue gases escape into the room instead of flowing up the vent.