Practice Test Geeks(HERS) Home Energy Rater Certification Practice Test
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Duct Leakage Testing Flashcards

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

Read the first 7 Duct Leakage Testing flashcards as text

  1. What does the term 'duct leakage to outside' (Qto) specifically measure?

    Answer: Air leaking between the duct system and unconditioned space

    Duct leakage to outside (Qto) measures air exchanged between the duct system and unconditioned spaces such as attics, crawlspaces, or garages.

  2. During a duct leakage test, all registers are sealed with tape and plugs. What is the purpose of this step?

    Answer: To isolate the duct system so only duct envelope leakage is measured

    Sealing registers isolates the duct system from the living space so that the Duct Blaster measures only leakage through duct seams and connections.

  3. A home has a Duct Leakage to Outside of 8% of floor area. Under ENERGY STAR v3.2, what is the maximum allowable Qto as a percentage of conditioned floor area?

    Answer: 4%

    ENERGY STAR v3.2 requires duct leakage to outside to be no more than 4 CFM25 per 100 sq ft of conditioned floor area.

  4. What unit is most commonly used to express duct leakage test results in the U.S.?

    Answer: CFM at 25 Pascals (CFM25)

    Duct leakage in the U.S. is standardized at CFM25, meaning cubic feet per minute of airflow at 25 Pascals of induced pressure.

  5. Which of the following conditions would MOST likely cause a duct leakage test to underestimate actual leakage?

    Answer: Registers that were not fully sealed before testing

    Incompletely sealed registers allow conditioned air to pass through, bypassing the Duct Blaster and causing the measured leakage to be lower than actual.

  6. How does the 'pressure matching' technique help when testing duct leakage to outside?

    Answer: It pressurizes the house to match duct pressure, isolating outside leakage

    Pressure matching uses a blower door to bring the house to the same pressure as the duct system, effectively nullifying leakage paths through the building envelope and isolating outside leakage.

  7. A Duct Blaster reading shows 180 CFM25 total leakage for a 1,800 sq ft home. What is the duct leakage expressed as CFM25 per 100 sq ft?

    Answer: 10 CFM25/100 sq ft

    180 CFM25 ÷ 1,800 sq ft × 100 = 10 CFM25 per 100 sq ft of conditioned floor area.