Practice Test Geeks(HERS) Home Energy Rater Certification Practice Test
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Diagnostics & Performance 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 Diagnostics & Performance Testing flashcards as text

  1. During a combustion appliance zone (CAZ) test, the technician finds that a draft hood-equipped water heater depressurizes the CAZ by 5 Pa when all exhaust fans run simultaneously. What does this indicate?

    Answer: There is a spillage risk and corrective action may be needed

    Depressurizing a CAZ by 5 Pa or more while draft-hood appliances are present can cause backdrafting or spillage, requiring further investigation and remediation.

  2. Which RESNET standard governs HERS field verification sampling protocols?

    Answer: ANSI/RESNET/ICC 380

    ANSI/RESNET/ICC 380 establishes the test methods and field verification protocols used by HERS raters for sampling and diagnostic testing.

  3. A HERS rater is verifying insulation in a vented attic. The rated R-value is R-38 but the depth gauge shows an average of 9.5 inches of blown fiberglass. What is the likely finding?

    Answer: Fail, because 9.5 inches of blown fiberglass typically provides approximately R-30, not R-38

    Blown fiberglass provides roughly R-2.5 to R-3 per inch; at 9.5 inches that is approximately R-24 to R-29, well short of R-38.

  4. What is the primary reason a HERS rater depressurizes the house to -50 Pa during a blower door test rather than a lesser pressure?

    Answer: To amplify small leaks so they can be measured accurately and reproducibly

    Testing at -50 Pa creates a standardized pressure that amplifies airflow through small cracks, making them measurable and results comparable across different homes and testers.

  5. When using a duct blaster to measure duct leakage to outside (Qout), the technician must cancel out house leakage. Which technique accomplishes this?

    Answer: Simultaneously operating the blower door to maintain house pressure equal to duct pressure

    The simultaneous blower door and duct blaster technique pressurizes the house to equal the duct test pressure, canceling house leakage so only duct-to-outside leakage is measured.

  6. A rater measures window U-factor using a NFRC label that reads 0.30. The energy model uses 0.28. Which value should be used for compliance verification?

    Answer: The NFRC-labeled value of 0.30 as the as-built condition

    Field verification must reflect as-built conditions; the NFRC label on the installed product (0.30) is the verified value and must be entered into the energy model.

  7. What does a high 'worst-case' CAZ depressurization reading indicate during a combustion safety test?

    Answer: Exhaust fans and the HVAC system together create enough negative pressure to cause appliance backdrafting

    High worst-case CAZ depressurization means the combined operation of exhaust devices creates sufficient negative pressure to overcome natural draft and pull flue gases back into the living space.