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Ductless Mini-Split Systems Flashcards

7 cards from real HVAC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Ductless Mini-Split Systems flashcards as text

  1. What is the typical refrigerant line set length limit for most residential ductless mini-split systems without additional refrigerant charge?

    Answer: 25 feet

    Most residential mini-split systems are pre-charged for approximately 25 feet of line set; longer runs require additional refrigerant.

  2. Which component in a ductless mini-split system is responsible for reversing refrigerant flow to switch between heating and cooling modes?

    Answer: Reversing valve

    The reversing (or four-way) valve redirects refrigerant flow to switch the system between heating and cooling operation.

  3. A mini-split indoor unit is producing a musty odor. What is the most likely cause?

    Answer: Dirty or moldy evaporator coil and drain pan

    Mold and mildew growth on the evaporator coil and drain pan is the most common source of musty odors in mini-split air handlers.

  4. What does the SEER2 rating measure for a ductless mini-split system?

    Answer: Cooling efficiency over a cooling season

    SEER2 (Seasonal Energy Efficiency Ratio 2) measures the cooling output divided by electrical energy input over a typical cooling season.

  5. When installing a mini-split indoor unit on an interior wall, what is the primary concern with the condensate drain line?

    Answer: The drain must slope downward at least 1/4 inch per foot to flow by gravity

    Condensate must drain by gravity, requiring a continuous downward slope of at least 1/4 inch per foot to prevent water backup and overflow.

  6. What happens to a ductless mini-split system's heating capacity as outdoor temperature drops significantly below its rated condition?

    Answer: Heating capacity decreases as outdoor temperature drops

    As outdoor temperature drops, there is less heat energy available in the outdoor air for the heat pump to extract, reducing heating capacity.

  7. Which type of ductless mini-split installation requires penetrating the building envelope for refrigerant line sets?

    Answer: All ductless mini-split configurations

    All ductless mini-split systems require refrigerant line sets connecting indoor and outdoor units, which must pass through the building envelope.