HERS Rating Standards & Compliance 3 — Questions and Answers
Question 1: When performing duct leakage testing for a HERS rating, which metric represents total duct leakage to outside the conditioned space?
- Duct leakage total (CFM25 total)
- Duct leakage to outside (CFM25 out) (Correct answer)
- Envelope leakage (ACH50)
- Supply imbalance pressure (Pascals)
Correct answer: Duct leakage to outside (CFM25 out)
CFM25 out (duct leakage to outside) measures air escaping the duct system into unconditioned spaces, which directly affects HERS scoring.
Question 2: A RESNET-certified rater discovers mid-inspection that insulation has been installed at a lower R-value than specified. What is the correct action?
- Rate the home using the specified R-value and note it in the file
- Document the discrepancy, rate using the as-built value, and notify the Provider (Correct answer)
- Refuse to complete the rating until insulation is corrected
- Average the specified and as-built values for the rating
Correct answer: Document the discrepancy, rate using the as-built value, and notify the Provider
Raters must document and use as-built conditions in the rating; discrepancies must be reported to the Rating Provider per RESNET quality assurance requirements.
Question 3: Which RESNET standard addresses measurement of airtightness and ventilation airflows in residential buildings?
- ANSI/RESNET/ICC 301
- ANSI/RESNET/ICC 380 (Correct answer)
- ANSI/ASHRAE/IES 90.1
- ANSI/ACCA Manual J
Correct answer: ANSI/RESNET/ICC 380
ANSI/RESNET/ICC 380 establishes standard test methods for airtightness and mechanical ventilation airflow measurement.
Question 4: For a home rated under ENERGY STAR Certified Homes Version 3.2, what additional requirement beyond HERS Index applies?
- HERS Index must be 60 or below without PV credit
- All mandatory requirements in the ENERGY STAR checklist must be verified (Correct answer)
- Third-party mechanical system inspection is waived
- Duct leakage to outside must be zero
Correct answer: All mandatory requirements in the ENERGY STAR checklist must be verified
ENERGY STAR requires both HERS Index compliance AND verification of all mandatory thermal enclosure, HVAC, and water management checklist items.
Question 5: Under RESNET's quality assurance oversight, what percentage of a rater's confirmed ratings must be reviewed by the Rating Provider annually?
- 5%
- 10% (Correct answer)
- 15%
- 25%
Correct answer: 10%
RESNET requires Rating Providers to conduct quality assurance reviews on a minimum of 10% of each rater's confirmed ratings annually.
Question 6: Which condition allows a rater to use the 'worst-case' duct leakage value from a prior test on a repeated floor plan?
- Builder certification that plans are identical
- Sampling protocol approval from the Rating Provider (Correct answer)
- State energy code exemption for tract housing
- RESNET national waiver for production builders
Correct answer: Sampling protocol approval from the Rating Provider
RESNET's sampling protocol, when approved by the Provider, allows repeated identical floor plans to use test results from a sampled representative unit.
Question 7: The HERS Index scale is defined such that a score of 0 represents:
- A home with no energy consumption from any source
- A home that produces as much energy as it consumes on an annual basis (net-zero) (Correct answer)
- A home 100% more efficient than the reference home
- A home meeting the 2006 IECC minimum requirements
Correct answer: A home that produces as much energy as it consumes on an annual basis (net-zero)
A HERS Index of 0 represents a net-zero energy home that produces as much energy annually as it consumes.
HERS Rating Standards & Compliance 3
When performing duct leakage testing for a HERS rating, which metric represents total duct leakage to outside the conditioned space?