RESNET HERS Home Energy Rater National Standard Exam — Questions and Answers

Question 1: When a conflict arises between standard procedures and a unique situation in Water Heating Efficiency, what should a HERS professional prioritize?

The preference of the client or stakeholder
Strict adherence to written procedures without exception
Safety and ethical obligations while seeking expert consultation (Correct answer)
The most cost-effective solution available

Correct answer: Safety and ethical obligations while seeking expert consultation

Safety and ethics always take priority in Water Heating Efficiency. When standard procedures don't adequately address a unique situation, consulting with experienced colleagues or supervisors ensures both safety and professional standards are maintained.

Question 2: Which direction does heat naturally flow?

From warmer to cooler areas (Correct answer)
From cooler to warmer areas
Away from insulation
In a circular pattern

Correct answer: From warmer to cooler areas

Heat always moves from a warmer object to a cooler one until thermal equilibrium is reached.

Question 3: What is the HERS Index score that represents a home meeting the minimum requirements of the 2006 IECC (the RESNET Reference Home baseline)?

75
85
130
100 (Correct answer)

Correct answer: 100

A HERS Index of 100 represents a home that uses exactly the same amount of energy as the RESNET Reference Home, which is based on the 2006 IECC.

Question 4: An exhaust-only ventilation system draws outdoor replacement air into the home primarily through:

A dedicated supply duct connected to the air handler return
The plumbing drain-waste-vent (DWV) stack
An HRV or ERV core mounted at the air handler
Intentional envelope leakage paths and passive fresh air inlets (Correct answer)

Correct answer: Intentional envelope leakage paths and passive fresh air inlets

Exhaust-only systems depressurize the home, causing outdoor air to infiltrate through envelope leakage paths and any intentionally installed passive makeup air inlets.

Question 5: What is the relationship between sensible heat and latent heat in building HVAC loads?

Sensible heat refers to duct losses; latent heat refers to envelope losses
Sensible and latent heat are identical concepts applied to different building systems
Sensible heat changes air temperature; latent heat involves the energy of phase change (moisture) (Correct answer)
Sensible heat is the total heat load; latent heat is the portion from solar radiation

Correct answer: Sensible heat changes air temperature; latent heat involves the energy of phase change (moisture)

Sensible heat changes the dry-bulb temperature of air, while latent heat is associated with moisture (water vapor) addition or removal without temperature change.

Question 6: When a rater updates a preliminary 'design rating' to a final 'confirmed rating' in HERS software, which values typically change?

The HERS Index reference home is recalculated from scratch
Inputs are updated to reflect as-built conditions, including tested blower door and duct leakage results (Correct answer)
Only the window specifications are updated
Only the builder's name and certification date are changed

Correct answer: Inputs are updated to reflect as-built conditions, including tested blower door and duct leakage results

A confirmed rating replaces estimated design values with field-verified data including measured air leakage, duct leakage, and verified insulation levels.

Question 7: Which HERS software input directly accounts for the number of bedrooms when calculating domestic hot water consumption?

The water heater UEF rating
The pipe insulation R-value
The setpoint temperature input field
The hot water draw profile, which is sized based on number of bedrooms (Correct answer)

Correct answer: The hot water draw profile, which is sized based on number of bedrooms

HERS Reference Home hot water consumption is calculated using a draw schedule that scales with the number of bedrooms, assuming more occupants in larger homes.

Question 8: What distinguishes an active solar thermal system from a passive solar thermal system?

Active systems only function in climates with more than 300 sunny days per year
Active systems store energy in phase-change materials
Active systems use evacuated tube collectors while passive use flat-plate collectors
Active systems use pumps and controls to move the heat transfer fluid (Correct answer)

Correct answer: Active systems use pumps and controls to move the heat transfer fluid

Active solar thermal systems rely on pumps, fans, and controls to circulate the heat transfer fluid, whereas passive systems use natural convection or thermosiphon principles.

Question 9: What is the difference between a 'confirmed' rating and a 'sampled' rating in HERS software submissions?

Confirmed ratings are for new construction; sampled ratings are for existing homes
Confirmed ratings are fully tested; sampled ratings rely on a tested sample unit within a provider sampling protocol (Correct answer)
There is no functional difference in the software output
Confirmed ratings use blower door results; sampled ratings use estimated infiltration

Correct answer: Confirmed ratings are fully tested; sampled ratings rely on a tested sample unit within a provider sampling protocol

Under RESNET's sampling protocol, some homes in a subdivision can use test results from a sampled unit, while confirmed ratings require individual testing of each home.

Question 10: Which standard provides the test method for measuring air leakage of building envelopes using a blower door?

RESNET Chapter 8
ASTM E1825
ASTM E779 (Correct answer)
ASHRAE 62.2

Correct answer: ASTM E779

ASTM E779 is the standard test method for determining air leakage rate by fan pressurization used in blower door testing.

Question 11: A HERS rater completes a rating and later learns the homeowner plans to use the rating to fraudulently obtain an energy-efficiency mortgage. What should the rater do?

Contact the mortgage lender directly to approve the loan
Withdraw the rating and report the situation to their rater provider (Correct answer)
Re-rate the home at a lower score to prevent the loan
Do nothing since the rating itself was accurate

Correct answer: Withdraw the rating and report the situation to their rater provider

When a rater discovers their work is being misused for fraud, ethics require withdrawal of the rating and notification to the rater provider for further action.

Question 12: Which of the following building penetrations is MOST commonly identified as a major source of air leakage during blower door testing?

Exterior door panels
Top plates and attic bypasses (Correct answer)
Foundation footings
Window glazing

Correct answer: Top plates and attic bypasses

Top plates and attic bypasses — including gaps around ceiling electrical boxes, plumbing chases, and partition wall top plates — are among the largest sources of air leakage in residential buildings.

Question 13: In REM/Rate, which ceiling type entry should be used for a vaulted ceiling with insulation between rafters?

Knee wall with attic storage
Flat ceiling with attic above
Cathedral ceiling with continuous insulation cavity (Correct answer)
Raised heel truss flat ceiling

Correct answer: Cathedral ceiling with continuous insulation cavity

A vaulted ceiling insulated between rafters is modeled as a cathedral ceiling in REM/Rate, with the rafter cavity depth determining maximum R-value.

Question 14: In the context of building envelope performance, what is 'air washing' of insulation?

Cold air moving through or around insulation, degrading its effective thermal resistance (Correct answer)
The process of removing moisture from wet insulation using forced air
Using air pressure to test insulation continuity
Cleaning insulation surfaces with pressurized air during installation

Correct answer: Cold air moving through or around insulation, degrading its effective thermal resistance

Air washing occurs when cold air infiltrates around or through insulation, carrying heat away by convection and significantly reducing its effective R-value.

Question 15: In REM/Rate software, what does the 'reference home' represent?

The most efficient home in the neighborhood
The highest-performing home in the rating database
A standardized code-minimum home used as a baseline for HERS scoring (Correct answer)
The rater's personal residence used for calibration

Correct answer: A standardized code-minimum home used as a baseline for HERS scoring

The reference home is a code-minimum home built to IECC specifications that serves as the 100-point baseline for HERS Index calculations.

Question 16: What does ACH50 measure in residential energy testing?

Average ceiling height at 50°F
Annual cooling hours at 50% load
Air conditioning hours per season
Air changes per hour at 50 Pascals pressure difference (Correct answer)

Correct answer: Air changes per hour at 50 Pascals pressure difference

ACH50 is the number of air changes per hour measured when the home is pressurized or depressurized to 50 Pascals.

Question 17: A home has a measured air leakage of 1,800 CFM50 and a conditioned volume of 15,000 cubic feet. What is the ACH50?

0.12
120
8.3
7.2 (Correct answer)

Correct answer: 7.2

ACH50 = (CFM50 × 60) / conditioned volume = (1,800 × 60) / 15,000 = 7.2 ACH50.

Question 18: Which insulation material has the highest R-value per inch?

Fiberglass batt
Closed-cell spray foam (Correct answer)
Open-cell spray foam
Cellulose

Correct answer: Closed-cell spray foam

Closed-cell spray foam provides approximately R-6 to R-7 per inch, the highest among common insulation materials.

Question 19: How does water hardness affect water heater efficiency over time?

Hard water increases thermal conductivity, improving heat transfer to stored water
Water hardness has no measurable effect on storage water heater performance
Mineral scale deposits on heating elements and tank walls reduce heat transfer efficiency and increase energy use (Correct answer)
Hard water reduces UEF by increasing electrical resistance in heating elements

Correct answer: Mineral scale deposits on heating elements and tank walls reduce heat transfer efficiency and increase energy use

Calcium and magnesium deposits from hard water form scale on heating elements and tank interiors, acting as insulation that forces the heater to work harder and consume more energy to maintain setpoint temperature.

Question 20: During HVAC evaluation, a rater tests duct leakage with the air handler operating and measures pressure pan readings. What do high pressure pan readings at a register indicate?

The register is correctly sealed and delivering full airflow
There is significant duct leakage near that register or branch duct (Correct answer)
The register damper is closed
The filter is restricting airflow at that register

Correct answer: There is significant duct leakage near that register or branch duct

High pressure pan readings indicate that the duct near that register is leaking, reducing pressure and airflow delivered to the room.

Question 21: A HERS rater notes fiberglass batts in a wall cavity with visible gaps and voids around electrical boxes. How does this affect the assembly?

Only affects fire resistance, not energy performance
Improves ventilation behind the wall
Significantly increases air leakage and reduces effective R-value (Correct answer)
No effect; batts are rated for installed conditions

Correct answer: Significantly increases air leakage and reduces effective R-value

Gaps and voids around penetrations allow air movement through the insulation and create thermal bypasses that substantially reduce effective R-value.

Question 22: Which software feature allows a HERS rater to model a home with both a gas furnace and a heat pump operating together?

Parallel load distribution
Dual-fuel heat pump modeling
Hybrid heating system input (Correct answer)
Sequential equipment scheduling

Correct answer: Hybrid heating system input

A hybrid heating system input in energy rating software allows modeling of dual-fuel configurations where a heat pump and backup furnace operate together.

Question 23: Per ASHRAE 62.2, kitchen exhaust fans with airflow ratings at or below 400 CFM must have a maximum sound rating of:

5 sones
1 sone
2 sones
3 sones (Correct answer)

Correct answer: 3 sones

ASHRAE 62.2 Section 5.1 limits kitchen exhaust fan noise to a maximum of 3 sones for intermittent fans rated at or below 400 CFM to encourage occupant use.

Question 24: When a conflict arises between standard procedures and a unique situation in HERS Index Scoring, what should a HERS professional prioritize?

Strict adherence to written procedures without exception
The most cost-effective solution available
The preference of the client or stakeholder
Safety and ethical obligations while seeking expert consultation (Correct answer)

Correct answer: Safety and ethical obligations while seeking expert consultation

Safety and ethics always take priority in HERS Index Scoring. When standard procedures don't adequately address a unique situation, consulting with experienced colleagues or supervisors ensures both safety and professional standards are maintained.

Question 25: What unit is most commonly used to express duct leakage test results in the U.S.?

Air Changes per Hour (ACH)
CFM at 25 Pascals (CFM25) (Correct answer)
Pascals per hour (Pa/hr)
Liters per second (L/s)

Correct answer: CFM at 25 Pascals (CFM25)

Duct leakage in the U.S. is standardized at CFM25, meaning cubic feet per minute of airflow at 25 Pascals of induced pressure.

Question 26: In HERS ratings, what is the correct term for the total area of all surfaces separating conditioned space from unconditioned space or outdoors?

Gross wall area
Conditioned floor area
Building shell perimeter
Thermal envelope area (Correct answer)

Correct answer: Thermal envelope area

The thermal envelope encompasses all surfaces—walls, roof, floors, windows, and doors—that bound the conditioned space.

Question 27: A rater measures duct leakage to outside (Qn,out) at 6% of conditioned floor area on a new construction home. Does this meet the 2021 IECC requirement?

No, 2021 IECC requires ≤4 CFM25 per 100 sq ft to outside (Correct answer)
No, 2021 IECC requires zero duct leakage to outside
Yes, 6% is within the 8% allowance
Yes, the standard only applies to total leakage not leakage to outside

Correct answer: No, 2021 IECC requires ≤4 CFM25 per 100 sq ft to outside

The 2021 IECC requires duct leakage to outside not to exceed 4 CFM25 per 100 square feet of conditioned floor area.

Question 28: Which of the following scenarios would result in TWO homes with different HERS Index scores even if they have identical construction?

Both homes are identical in design but built in different climate zones (Correct answer)
Both homes are in the same climate zone but have different owners
Both homes are rated by different raters using the same approved software
Both homes have the same square footage but different colors

Correct answer: Both homes are identical in design but built in different climate zones

The HERS reference home is built to the same climate as the rated home, so identical construction in different climate zones will produce different HERS scores because heating and cooling loads differ.

Question 29: When a conflict arises between standard procedures and a unique situation in Building Envelope & Insulation, what should a HERS professional prioritize?

Strict adherence to written procedures without exception
The most cost-effective solution available
The preference of the client or stakeholder
Safety and ethical obligations while seeking expert consultation (Correct answer)

Correct answer: Safety and ethical obligations while seeking expert consultation

Safety and ethics always take priority in Building Envelope & Insulation. When standard procedures don't adequately address a unique situation, consulting with experienced colleagues or supervisors ensures both safety and professional standards are maintained.

Question 30: In Building Envelope & Insulation, what is the FIRST step a HERS professional should take when encountering a new case or situation?

Document the situation and wait for further instructions
Consult with a supervisor before taking any action
Implement an immediate solution based on past experience
Conduct a comprehensive assessment and gather all relevant information (Correct answer)

Correct answer: Conduct a comprehensive assessment and gather all relevant information

In Building Envelope & Insulation, a thorough initial assessment ensures all relevant factors are identified before deciding on an appropriate course of action. This systematic approach is fundamental to Home Energy Rater practice.

Question 31: In the HERS rating system, what does a Projected Rating (PR) represent?

A rating that has been confirmed by a Quality Assurance Designee
A rating based on design plans before construction is complete (Correct answer)
A rating based on utility bill analysis
A rating after all on-site testing is finished

Correct answer: A rating based on design plans before construction is complete

A Projected Rating is based on building plans and specifications before or during construction, prior to final on-site verification testing.

RESNET HERS Home Energy Rater National Standard Exam

The RESNET HERS Rater National Standard Exam certifies candidates on building science principles and home energy rating procedures. It covers field testing protocols, HVAC evaluation, and energy modeling under the Home Energy Rating System standard.

Questions

120 min

Time Limit

73%

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