RESNET HERS National Rater Test — Questions and Answers

Question 1: When a HERS rater certifies a home using the confirmed rating pathway, which of the following site inspections is required?

Foundation inspection only
Pre-drywall inspection only
Both pre-drywall and final inspections (Correct answer)
Final inspection only

Correct answer: Both pre-drywall and final inspections

The confirmed rating pathway requires both a pre-drywall inspection (to verify insulation and air sealing) and a final inspection with diagnostic testing.

Question 2: Which RESNET policy requires that rating software used for HERS ratings be tested against a standard set of reference cases?

RESNET Software Approval Process (Correct answer)
RESNET Publication 002
RESNET Home Energy Audit Standard
RESNET Mortgage Industry National Standards

Correct answer: RESNET Software Approval Process

The RESNET Software Approval Process requires rating software to be validated against standardized reference test cases before it can be used for official HERS ratings.

Question 3: A HERS Rater is modeling a two-story home with a vented, unconditioned attic. The attic floor is insulated, and the air handler and all ductwork are located in this attic. How must the location of the duct system be specified in the energy modeling software for an accurate rating?

Inside conditioned space, because it serves the house.
Outside conditioned space. (Correct answer)
In a buffer space, such as an unconditioned basement.
The location does not need to be specified if duct leakage is tested.

Correct answer: Outside conditioned space.

The thermal boundary of the home is at the insulated attic floor. A vented attic is considered 'outside conditioned space' because it is exposed to outdoor temperature fluctuations. Any mechanical systems or ductwork located in the attic must be modeled as being outside, which correctly accounts for the significant thermal losses and gains they will experience, as well as the impact of duct leakage to the outdoors.

Question 4: What is a duct leakage test used for?

Measure airflow in return grilles
Determine duct system airtightness (Correct answer)
Check refrigerant level
Assess air quality

Correct answer: Determine duct system airtightness

A duct leakage test identifies leaks in a duct system to assess efficiency and improve HVAC performance.

Question 5: For a home rated under ENERGY STAR Certified Homes Version 3.2, what additional requirement beyond HERS Index applies?

Third-party mechanical system inspection is waived
HERS Index must be 60 or below without PV credit
Duct leakage to outside must be zero
All mandatory requirements in the ENERGY STAR checklist must be verified (Correct answer)

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 6: What is the RESNET-defined default internal gains assumption used in HERS energy modeling for occupancy?

Internal gains are fixed at 2,400 BTU/hr regardless of home size
Occupancy is calculated as 1 person per 300 square feet of conditioned floor area
Standard occupancy is set at 0.5 + (CFA/100)^0.43 persons as defined in ANSI/RESNET/ICC 301 (Correct answer)
Occupancy defaults to 4 persons for all homes under 3,000 square feet

Correct answer: Standard occupancy is set at 0.5 + (CFA/100)^0.43 persons as defined in ANSI/RESNET/ICC 301

ANSI/RESNET/ICC 301 specifies occupancy as 0.5 + (CFA/100)^0.43, ensuring larger homes have proportionally more occupants in the reference calculation.

Question 7: Under RESNET Standards, which of the following is NOT an approved pathway for conducting a HERS rating on new construction?

Confirmed rating with field inspections
Sampled rating using the sampling protocol
Desktop rating using plans only with no inspections (Correct answer)
Energy Performance Score pathway

Correct answer: Desktop rating using plans only with no inspections

RESNET does not allow a fully desktop-only rating with no field inspections for new construction; some level of field verification is always required.

Question 8: A new home scores a HERS 55 and its neighbor scores a HERS 85. Approximately how much more energy efficient is the first home?

About 30% more efficient (Correct answer)
About 85% more efficient
About 55% more efficient
Exactly twice as efficient

Correct answer: About 30% more efficient

Each point on the HERS scale represents approximately 1% more or less energy use, so a 30-point difference equals roughly 30% greater efficiency.

Question 9: What OSHA permissible exposure limit (PEL) for CO over an 8-hour workday should inform a HERS rater's concern about ambient indoor CO levels?

50 ppm (Correct answer)
9 ppm
200 ppm
35 ppm

Correct answer: 50 ppm

OSHA's 8-hour TWA PEL for CO is 50 ppm; sustained indoor concentrations approaching this level represent a serious occupational and residential health hazard.

Question 10: In HERS ratings, what is the 'rated home' compared against to generate the index score?

The local utility's average residential customer energy use
A computer model of the same home built to the RESNET reference specifications (Correct answer)
The national average home from the latest census
The best-performing home in the same climate zone

Correct answer: A computer model of the same home built to the RESNET reference specifications

The rated home is compared against a reference version of that same home modeled to RESNET/ICC 301 specifications to produce the index.

Question 11: In a hot-humid climate, where should the vapor retarder be placed in a wall assembly?

On the interior (warm-in-winter) side
On the exterior side, toward the hot exterior (Correct answer)
In the center of the cavity
No vapor retarder is needed in hot-humid climates

Correct answer: On the exterior side, toward the hot exterior

In hot-humid climates, the dominant moisture drive is inward from the hot exterior, so the vapor retarder belongs on the exterior side.

Question 12: Which metric best represents the air tightness of a home independent of its volume?

CFM25 out
CFM50
ELA
ACH50 (Correct answer)

Correct answer: ACH50

ACH50 (air changes per hour at 50 Pa) normalizes CFM50 by home volume, allowing meaningful comparisons between homes of different sizes.

Question 13: In HERS rating methodology, the 'rated home' is compared against a 'reference home' that is defined as:

A home of identical geometry and orientation using RESNET-specified standard features (Correct answer)
The least efficient home allowed by current code
The average energy use of existing homes in the same state
A standard 2,000 sq ft home in a neutral climate zone

Correct answer: A home of identical geometry and orientation using RESNET-specified standard features

The HERS reference home mirrors the rated home's size and geometry but uses code-minimum features as defined in ANSI/RESNET/ICC 301.

Question 14: A rater models two identical homes except one has east/west-facing glazing and the other has south/north-facing glazing. In a heating-dominated climate, which will likely have a lower HERS Index?

The east/west-facing home because morning sun reduces heating demand
The south/north-facing home because south windows maximize passive solar gains in winter (Correct answer)
Both homes will have identical HERS Index scores because total window area is the same
The north-facing home because it avoids summer overheating penalties

Correct answer: The south/north-facing home because south windows maximize passive solar gains in winter

South-facing windows capture winter solar gains more effectively than east/west windows, reducing heating energy and lowering the HERS Index in heating-dominated climates.

Question 15: A marketing team claims a home has a 'HERS Score of 42 — 58% better than average.' Is this statement accurate?

No, because HERS compares to average US homes, not a reference home
Yes, because 42 is 58 points below 100, representing 58% better energy performance than the reference (Correct answer)
Yes, but only if the home is in Climate Zone 4 or above
No, because the math should read 42% better, not 58%

Correct answer: Yes, because 42 is 58 points below 100, representing 58% better energy performance than the reference

A HERS 42 is 58 points below the reference home score of 100, correctly indicating approximately 58% better energy performance than the reference.

Question 16: A HERS Rater is inspecting a newly installed high-efficiency condensing furnace that is a direct-vent, sealed-combustion unit. The intake and exhaust pipes are routed directly to the outdoors. Which combustion safety test is NOT required for this type of appliance?

A visual inspection of the vent terminations for proper clearance.
A worst-case depressurization and spillage test. (Correct answer)
A measurement of carbon monoxide (CO) in the flue gas.
A gas leak check at the pipe fittings near the unit.

Correct answer: A worst-case depressurization and spillage test.

Direct-vent, sealed-combustion appliances draw all of their combustion air directly from the outdoors and have a sealed exhaust system. Because they do not communicate with the indoor air, they are not susceptible to depressurization-induced backdrafting or spillage. Therefore, a worst-case depressurization test is not applicable to these units. However, CO testing, gas leak checks, and visual inspection of the system are still important safety checks.

Question 17: What does the term 'thermal bypass' refer to in a HERS field inspection context?

An alternate refrigerant circuit in a heat pump
A duct section that bypasses the heat exchanger
Air movement around or through insulation that reduces its effective R-value (Correct answer)
A mechanical damper that bypasses the air handler

Correct answer: Air movement around or through insulation that reduces its effective R-value

A thermal bypass is any air movement pathway that allows air to flow around insulation, significantly reducing its effective thermal resistance.

Question 18: A HERS rater finds that recessed can lights are installed in an insulated ceiling. Why is this a concern for energy performance?

Can lights increase cooling load from heat gain
Can lights require dedicated circuits that affect the HERS score
Non-airtight can lights are significant air leakage points that bypass ceiling insulation (Correct answer)
IC-rated can lights cannot be covered with insulation

Correct answer: Non-airtight can lights are significant air leakage points that bypass ceiling insulation

Non-airtight recessed lights create direct air leakage pathways through the ceiling, bypassing insulation and significantly increasing infiltration.

Question 19: In HERS field testing, what is the purpose of the 'pressure pan' test?

To measure air pressure in the HVAC supply plenum
To calibrate the duct blaster before testing
To identify which specific ceiling or wall cavities are connected to the duct system as leakage pathways (Correct answer)
To measure return static pressure during HVAC operation

Correct answer: To identify which specific ceiling or wall cavities are connected to the duct system as leakage pathways

A pressure pan placed over a ceiling penetration or register opening while the house is depressurized identifies leaky duct connections by revealing pressure communication with cavities.

Question 20: Which climate-related factor most influences whether a HERS rater recommends a vented or unvented attic assembly?

The climate zone, humidity levels, and roof geometry (Correct answer)
The local wind speed and prevailing wind direction
The age of the existing HVAC equipment in the attic
Annual heating degree days only

Correct answer: The climate zone, humidity levels, and roof geometry

Climate zone moisture conditions and roof geometry determine whether vented attics will introduce harmful humidity or whether unvented conditioned attics are more appropriate.

Question 21: What is the primary reason HERS raters must depressurize ducts to a specific pressure (typically 25 Pa) during a duct leakage test?

To standardize results so tests from different homes and raters are comparable (Correct answer)
To maximize airflow through the ducts
To replicate worst-case wind conditions
To satisfy fire code requirements

Correct answer: To standardize results so tests from different homes and raters are comparable

Standardizing at 25 Pa ensures that duct leakage measurements are consistent and comparable across different test conditions, homes, and raters.

Question 22: Under RESNET HERS standards, what is the Reference Home assumption for water heater efficiency used to calculate the HERS Index?

A code-minimum unit based on IECC for the home's location and size (Correct answer)
EF 0.58 electric storage
The same equipment as the rated home
A heat pump water heater at UEF 2.0

Correct answer: A code-minimum unit based on IECC for the home's location and size

The Reference Home uses a code-minimum water heater based on IECC requirements for the home's size and climate zone.

Question 23: What is the purpose of the 'Solar Heat Gain Coefficient' (SHGC) of a window?

It measures the window's resistance to conductive heat loss
It describes the ratio of visible light to UV light transmitted
It quantifies how much solar radiation passes through the window into the building (Correct answer)
It rates how well the frame resists air infiltration

Correct answer: It quantifies how much solar radiation passes through the window into the building

SHGC is a dimensionless number (0–1) indicating the fraction of incident solar radiation transmitted through a window as heat gain.

Question 24: When a HERS rater verifies equipment sizing, which method is the industry-accepted standard for performing residential load calculations?

IECC Table R403
ACCA Manual J (Correct answer)
ASHRAE 90.1
RESNET Chapter 3

Correct answer: ACCA Manual J

ACCA Manual J is the industry-accepted protocol for calculating residential heating and cooling loads.

Question 25: What condition can cause an induced-draft furnace to produce elevated CO even though it has a powered venting fan?

A high-efficiency condensing operation
A cracked heat exchanger allowing flue gas recirculation (Correct answer)
A properly operating inducer drawing room air for dilution
A correct air-fuel ratio with clean burners

Correct answer: A cracked heat exchanger allowing flue gas recirculation

A cracked heat exchanger in an induced-draft furnace can allow exhaust gases to recirculate through the combustion chamber, leading to incomplete combustion and elevated CO in both flue gases and supply air.

Question 26: Compared to a continuous recirculation system, how does a demand-controlled recirculation system affect energy use in HERS?

Demand-controlled systems are not recognized as a credit in current HERS ratings
Both systems have identical energy use in HERS calculations
Demand-controlled systems always consume more pump energy due to frequent start/stop cycling
Demand-controlled systems reduce standby heat losses by running only when activated by occupant demand (Correct answer)

Correct answer: Demand-controlled systems reduce standby heat losses by running only when activated by occupant demand

Demand-controlled recirculation systems activate only when hot water is requested, significantly reducing standby circulation losses compared to continuous or timer-based systems.

Question 27: What term describes duct leakage that exits into an unconditioned space such as an attic or crawlspace?

Envelope leakage
Duct leakage to inside
Duct leakage to outside (Correct answer)
Balancing bypass

Correct answer: Duct leakage to outside

Duct leakage that goes into unconditioned spaces (attic, crawlspace, garage) is called duct leakage to outside because it effectively leaves the conditioned envelope.

Question 28: Under RESNET Quality Installation (QII) standards, what insulation grading is assigned to a cavity filled to 100% of its intended depth with no voids?

Grade I (Correct answer)
Grade 0
Grade III
Grade II

Correct answer: Grade I

Grade I insulation installation means the cavity is completely and uniformly filled with no voids, compressions, or gaps.

Question 29: Which software tool is commonly used by HERS raters to calculate energy ratings and must be accredited by RESNET?

REM/Rate or equivalent RESNET-accredited software (Correct answer)
EnergyPlus
OpenStudio
eQUEST

Correct answer: REM/Rate or equivalent RESNET-accredited software

HERS ratings must be calculated using RESNET-accredited rating software such as REM/Rate, EnergyGauge, or other approved tools.

Question 30: When performing a duct leakage test in accordance with ANSI/RESNET/ICC 380, the duct system is typically pressurized or depressurized to what pressure differential relative to the surrounding space?

25 Pa (Correct answer)
50 Pa
10 Pa
75 Pa

Correct answer: 25 Pa

The standard test pressure for both total duct leakage and leakage to the outdoors, as specified by RESNET standards, is 25 Pascals (0.10 inches water column).

RESNET HERS National Rater Test

The RESNET HERS National Rater Test certifies candidates as Home Energy Rating System (HERS) Raters, evaluating knowledge of building science, energy systems, air leakage, insulation, and RESNET rating procedures required to perform residential energy audits and ratings.

Questions

65 min

Time Limit

73%

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