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
What is the minimum slope required for a horizontal drain pipe to ensure proper drainage by gravity?
Answer: 1/4 inch per foot
A minimum slope of 1/4 inch per foot (2%) is required for horizontal drain pipes 3 inches or smaller to maintain adequate flow velocity.
A home inspector observes a water heater with no pressure relief valve discharge pipe. What is the primary concern?
Answer: Steam and hot water could spray dangerously if the valve opens
Without a discharge pipe, an opening T&P valve could spray scalding water or steam directly at occupants, posing a serious burn hazard.
What does a home inspector look for when checking an air conditioning evaporator coil?
Answer: Ice buildup or blocked condensate drain
Ice on the evaporator coil indicates restricted airflow or low refrigerant, and a blocked condensate drain can cause water damage or system shutdown.
Which type of pipe is most commonly identified by its blue or black color and is acceptable for potable cold-water supply lines?
Answer: PEX
PEX (cross-linked polyethylene) is commonly color-coded blue for cold water and red for hot water, and is approved for potable water supply.
An inspector finds a gas furnace with a cracked heat exchanger. What is the recommended course of action?
Answer: Recommend immediate discontinuation of use and professional repair
A cracked heat exchanger can allow carbon monoxide to mix with supply air and enter living spaces, making it a life-safety issue requiring immediate action.
What is the purpose of a backflow preventer on a hose bibb (exterior faucet)?
Answer: To prevent contaminated water from siphoning back into the potable supply
A backflow preventer (vacuum breaker) stops contaminated water — such as from a garden hose left in a chemical solution — from being siphoned back into the home's potable water supply.
When inspecting supply ducts in an unconditioned attic, an inspector should be most concerned about:
Answer: Missing or inadequate insulation on ducts
Uninsulated ducts in a hot attic lose significant conditioned air energy and can cause condensation, reducing system efficiency and potentially causing moisture damage.