Plumbing & HVAC Systems Flashcards
7 cards from real INTERNACHI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Plumbing & HVAC Systems flashcards as text
Which condition in a plumbing system is described as water hammer?
Answer: Banging noise when a valve or faucet is quickly shut off
Water hammer is the banging or thudding sound caused by the sudden pressure wave when fast-moving water is abruptly stopped by a closing valve.
What does AFUE stand for in reference to heating equipment, and what does a higher number indicate?
Answer: Annual Fuel Utilization Efficiency; higher means more efficient
AFUE (Annual Fuel Utilization Efficiency) measures how much fuel is converted to heat; a rating of 95% means 95% of fuel energy becomes useful heat.
An inspector notices that a bathroom exhaust fan vents into the attic instead of to the exterior. What is the concern?
Answer: Moisture and mold can accumulate in the attic
Exhausting humid bathroom air into an attic introduces moisture that can lead to condensation, wood rot, and mold growth on framing and sheathing.
What is the minimum required distance between a gas water heater's pilot or burner and the floor in a garage installation?
Answer: 18 inches
In a garage, ignition sources such as pilot lights must be elevated at least 18 inches above the floor to reduce the risk of igniting gasoline vapors that pool low.
Which refrigerant was widely phased out of residential air conditioning systems due to ozone depletion concerns?
Answer: R-22 (Freon)
R-22 (chlorodifluoromethane, marketed as Freon) was phased out under the Clean Air Act because its chlorine atoms deplete stratospheric ozone.
A home inspector observes galvanic corrosion where copper pipe connects directly to a steel fitting. What should be used to prevent this?
Answer: A dielectric union or fitting
A dielectric union or fitting isolates dissimilar metals electrically, preventing the electrochemical reaction that causes accelerated corrosion at the joint.
What is the function of a condensate neutralizer on a high-efficiency condensing furnace?
Answer: It raises the pH of acidic condensate before it enters the drain
High-efficiency furnaces produce acidic condensate (pH 2–4) that can damage cast-iron drains; a neutralizer raises the pH to a safe level before disposal.