HERS Diagnostics & Performance Testing 3

Question 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?

Accepted Answer

There is a spillage risk and corrective action may be needed

Answer

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

Question 2

Which RESNET standard governs HERS field verification sampling protocols?

Accepted Answer

ANSI/RESNET/ICC 380

Answer

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

Question 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?

Accepted Answer

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

Answer

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.

Question 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?

Accepted Answer

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

Answer

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.

Question 5

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

Accepted Answer

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

Answer

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.

(HERS) Home Energy Rater Certification Practice Test

(HERS) Home Energy Rater Certification Practice Test

HERS Diagnostics & Performance Testing 3