Practice Test Geeks(HERS) Certified Home Energy Rating System Rater Practice Test
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Blower Door & Duct 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 Blower Door & Duct Testing flashcards as text

  1. During a blower door test, what effect does a large open fireplace damper have on the result?

    Answer: It increases the measured CFM50, making the house appear leakier

    An open fireplace damper is a large pathway to outside and will increase the measured infiltration (CFM50), inflating the apparent leakage of the building shell.

  2. What is the primary reason HERS raters must depressurize ducts to a specific pressure (typically 25 Pa) during a duct leakage test?

    Answer: To standardize results so tests from different homes and raters are comparable

    Standardizing at 25 Pa ensures that duct leakage measurements are consistent and comparable across different test conditions, homes, and raters.

  3. In a duct leakage test, CFM25 total is measured at 300 cfm and CFM25 out is measured at 180 cfm. What is the duct leakage to outside?

    Answer: 120 cfm

    Duct leakage to outside equals total leakage minus leakage to conditioned space: 300 − 180 = 120 cfm.

  4. Which condition must be established before starting a blower door test according to RESNET standards?

    Answer: All interior doors must be open

    RESNET requires all interior doors to be open so that the entire conditioned envelope is pressurized or depressurized uniformly during testing.

  5. What does a high ELA (Effective Leakage Area) value indicate about a home?

    Answer: The home has a large equivalent hole size and poor air sealing

    A high ELA means the combined leakage pathways are equivalent to a large hole, indicating poor envelope air tightness.

  6. During duct leakage testing, why is it important to seal all supply and return grilles before testing?

    Answer: To isolate duct leakage from building envelope leakage

    Sealing grilles ensures that airflow measured by the duct blaster represents only leakage through duct seams and connections, not intentional supply/return openings.

  7. A home tests at 6 ACH50. Which HERS reference home air leakage rate would this most closely correspond to for a typical new construction standard?

    Answer: It exceeds the typical new construction benchmark of 3 ACH50

    A common new construction benchmark is 3 ACH50 or less; 6 ACH50 is twice that limit, indicating the home is leakier than typical code expectations.