HERS HERS Index and Ratings Questions and Answers

Question 1

A HERS Rater is explaining the HERS Index to a client. What does a HERS Index score of 100 signify?

Accepted Answer

The home's energy performance is equivalent to that of the HERS Reference Home.

Answer

The HERS Index is a relative scale where 100 represents the energy performance of the HERS Reference Home, which is based on the 2006 International Energy Conservation Code (IECC). A lower score indicates better performance, and a higher score indicates worse performance.

Question 2

A newly constructed home receives a confirmed HERS Index of 65. How should the rater explain this result to the homeowner in terms of energy efficiency?

Accepted Answer

The home is 35% more energy efficient than a standard new home built to the HERS Reference Home specifications.

Answer

Each point below 100 on the HERS Index represents a 1% improvement in energy efficiency compared to the HERS Reference Home. Therefore, a score of 65 (100 - 65 = 35) means the home is 35% more energy efficient than the Reference Home.

Question 3

A builder is aiming for a home to achieve a HERS Index of 0. Which of the following is essential for achieving this specific score?

Accepted Answer

Incorporating on-site renewable energy generation, such as solar panels.

Answer

A HERS Index of 0 represents a Net Zero Energy Home, which means the home produces as much energy as it consumes over a year. While airtightness, high insulation levels, and efficient appliances are crucial for reducing consumption, achieving a score of 0 is only possible by offsetting the remaining energy use with on-site renewable power generation.

Question 4

Which of the following components is a fixed assumption for BOTH the HERS Reference Home and the Rated Home in an energy model, ensuring a fair comparison of the building envelope and systems?

Accepted Answer

Geographic location and climate data

Answer

To create an accurate relative comparison, the HERS rating methodology (ANSI/RESNET/ICC 301) specifies that the Rated Home and the HERS Reference Home must be modeled with the exact same location, climate data, orientation, and geometry. The efficiency of components like windows, insulation, and mechanical systems are then compared against the Reference Home's standard specifications.

Question 5

A HERS rating is performed on two identical homes built side-by-side. Home A has no on-site power generation and receives a HERS Index of 52. Home B has a photovoltaic (PV) system that meets 100% of its predicted annual energy consumption. What would be the HERS Index for Home B?

Accepted Answer

0

Answer

The HERS Index accounts for on-site power production. Since Home B is identical to Home A in terms of its consumption (HERS 52), adding a PV system that meets 100% of that consumption will offset it entirely, resulting in a Net Zero Energy Home, which is defined by a HERS Index of 0.

(HERS) Certified Home Energy Rating System Rater Practice Test

(HERS) Certified Home Energy Rating System Rater Practice Test

HERS HERS Index and Ratings Questions and Answers