RESNET HERS National Rater Test — Questions and Answers

Question 1: How does wind-driven rain most commonly enter a wall assembly in a climate with high wind exposure?

Condensation on the back side of the cladding
Vapor diffusion through exterior sheathing
Forced water entry through gaps and cracks under pressure (Correct answer)
Capillary action through the sill plate

Correct answer: Forced water entry through gaps and cracks under pressure

Wind pressure forces liquid water through gaps, cracks, and penetrations in the cladding and air barrier under positive pressure.

Question 2: When RESNET Standards reference 'normalized modified end use loads' (nMEUL), what is being calculated?

The peak demand load on local utility infrastructure from a group of rated homes
The actual measured energy consumption from utility bills after one year of occupancy
Adjusted heating and cooling loads used in the HERS Index calculation methodology (Correct answer)
The energy used by plug loads and appliances not covered by the HERS rating

Correct answer: Adjusted heating and cooling loads used in the HERS Index calculation methodology

nMEUL refers to normalized modified end use loads, which are the adjusted energy loads for heating and cooling used in the HERS Index calculation under ANSI/RESNET/ICC 301.

Question 3: A HERS rater measures duct leakage to outside at 52 CFM25 on a 1,800 sq ft home. What is the duct leakage to outside as a percentage of conditioned floor area?

4.2%
5.1%
2.9% (Correct answer)
3.5%

Correct answer: 2.9%

52 CFM25 divided by 1,800 sq ft equals approximately 2.9%, which is the standard way to normalize duct leakage to outside.

Question 4: For HERS rating purposes, what does 'verified duct leakage' mean when ducts are entirely inside conditioned space?

Total duct leakage is zero by definition
Only leakage to outside matters and is measured separately
The rater may use a default duct leakage value without testing (Correct answer)
Duct leakage to outside is assumed to equal total leakage

Correct answer: The rater may use a default duct leakage value without testing

When all ducts are confirmed to be within the conditioned envelope, RESNET allows raters to use a default duct leakage assumption rather than requiring a measured test.

Question 5: In HERS modeling software, what is meant by 'distribution system efficiency' for a forced-air system?

The ratio of blower motor electrical input to airflow output
The percentage of time the air handler operates at peak capacity
The efficiency of the air filter in removing particulates
The fraction of heating or cooling energy delivered to conditioned space after duct losses (Correct answer)

Correct answer: The fraction of heating or cooling energy delivered to conditioned space after duct losses

Distribution efficiency accounts for duct conduction and leakage losses, representing what fraction of the system's output actually reaches the conditioned living space.

Question 6: During a pressure diagnostics test, a rater measures -3 Pascals in a bedroom with the door closed and the HVAC system running. This indicates:

Excessive supply airflow to the bedroom relative to return air capacity (Correct answer)
The bedroom window is leaking
Adequate air balancing in the bedroom
Return air is located in the bedroom

Correct answer: Excessive supply airflow to the bedroom relative to return air capacity

A negative pressure in a bedroom with the door closed indicates more supply air is being delivered than can return, causing the room to be pressurized relative to... actually -3 Pa means the room is slightly negative, indicating insufficient supply or excessive return bypass — but typically a negative room with door closed means the return is pulling more than the supply delivers, suggesting the system is pulling from that room.

Question 7: What is the benefit of using dense-pack cellulose in existing wall cavities during an energy retrofit verified by a HERS rater?

It qualifies as a Grade I installation in new construction only
It eliminates the need for a blower door test
It fills voids and gaps that batts cannot reach, improving both insulation and air sealing (Correct answer)
It provides a Class I vapor barrier

Correct answer: It fills voids and gaps that batts cannot reach, improving both insulation and air sealing

Dense-pack cellulose fills irregular cavities and small gaps that batt insulation cannot access, improving both thermal and air barrier performance.

Question 8: Which factor is most critical when sizing a combustion air opening into a mechanical room containing atmospherically vented appliances?

The height of the ceiling in the room
The number of gas appliances present
The volume of the mechanical room
The BTU input of all appliances combined (Correct answer)

Correct answer: The BTU input of all appliances combined

Combustion air opening sizing is based on the total BTU/hr input of all combustion appliances in the space, per NFPA 54 and other codes.

Question 9: A HERS rater is testing a home with both a central forced-air system and a mini-split. How should the mini-split be treated in duct leakage testing?

Test the mini-split's air handler separately at 25 Pascals
Mini-splits have no ductwork and are not subject to duct leakage testing (Correct answer)
Include the mini-split refrigerant lines in the duct pressurization test
Estimate mini-split duct leakage at 4% of conditioned area by default

Correct answer: Mini-splits have no ductwork and are not subject to duct leakage testing

Mini-split systems are ductless — they deliver conditioned air directly without ductwork, so they are exempt from duct leakage testing requirements.

Question 10: During a duct pressurization test, a rater tapes all supply and return registers. What is the purpose of this step?

To isolate the duct system so only duct leakage is measured, not intentional airflow openings (Correct answer)
To prevent the HVAC fan from accidentally turning on
To simulate worst-case duct pressures during HVAC operation
To reduce the total duct volume being pressurized

Correct answer: To isolate the duct system so only duct leakage is measured, not intentional airflow openings

Taping registers closes the intentional airflow openings so the pressure test only measures unintended leakage in the duct system, not air escaping through registers.

Question 11: A HERS rater documents that the home uses a variable-speed air handler. What efficiency advantage does this provide compared to a single-speed unit?

Higher AFUE rating for heating
Lower electricity consumption during part-load operation (Correct answer)
Reduced refrigerant charge requirements
Elimination of duct leakage losses

Correct answer: Lower electricity consumption during part-load operation

Variable-speed air handlers consume significantly less electricity during part-load conditions, which represents the majority of operating hours.

Question 12: In HERS modeling, how is a home with a walkout basement partially below grade typically handled for foundation inputs?

Above-grade portions are modeled as walls and below-grade portions as basement walls with appropriate soil contact fractions (Correct answer)
Walkout basements default to the same U-factor as conditioned crawlspaces
The basement is always excluded from conditioned floor area calculations
The entire basement is modeled as a slab-on-grade foundation

Correct answer: Above-grade portions are modeled as walls and below-grade portions as basement walls with appropriate soil contact fractions

Software requires separate modeling of above-grade and below-grade wall fractions because heat loss rates differ significantly based on soil contact depth.

Question 13: During a duct blaster test, the technician notices pressure in the duct system won't reach 25 Pa even at maximum fan speed. What is the most likely cause?

The duct system is extremely tight with no leaks
The outside temperature is too cold
There is a large unsealed duct opening or disconnected duct section (Correct answer)
The manometer battery is dead

Correct answer: There is a large unsealed duct opening or disconnected duct section

If the duct blaster cannot reach 25 Pa, it usually means there is an extremely large leak—such as a disconnected duct section or an unsealed chase—allowing air to escape faster than the fan can pressurize the system.

Question 14: What is the HERS Index Score?

A building’s resale value
Indoor air quality level
Total construction cost
A numerical energy performance rating (Correct answer)

Correct answer: A numerical energy performance rating

The HERS Index Score measures a home's energy efficiency; lower scores indicate better performance.

Question 15: When a HERS rater verifies equipment sizing, which method is the industry-accepted standard for performing residential load calculations?

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

Correct answer: ACCA Manual J

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

Question 16: Which of the following hot water distribution improvements would most directly earn a HERS distribution efficiency credit?

Increasing water heater tank size from 40 to 80 gallons
Adding a second water heater in a remote bathroom addition
Installing a structured plumbing system with a central manifold and small-diameter individual home runs (Correct answer)
Increasing the water heater setpoint from 120°F to 140°F

Correct answer: Installing a structured plumbing system with a central manifold and small-diameter individual home runs

Structured plumbing (central manifold with individual small-diameter home runs) minimizes pipe volume and water wasted awaiting hot water, earning recognized HERS distribution efficiency credits.

Question 17: 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 III
Grade 0
Grade I (Correct answer)
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 18: Which fuel source typically yields the lowest HERS Index score (best rating) for space heating in a cold U.S. climate?

Natural gas furnace at 95% AFUE
Air-source heat pump at HSPF 10 (Correct answer)
Propane furnace at 96% AFUE
Electric resistance baseboard

Correct answer: Air-source heat pump at HSPF 10

A high-efficiency air-source heat pump moves 2–4 units of heat per unit of electricity, delivering a lower HERS Index than combustion heating.

Question 19: Which of the following is a common source of air leakage that a rater should pre-seal before a blower door test to avoid skewing results toward envelope leakage?

Electrical outlets on interior walls
Mechanical exhaust fans without dampers (Correct answer)
Attic hatch with no weatherstripping
Recessed lights on interior ceilings

Correct answer: Mechanical exhaust fans without dampers

Mechanical exhaust fans without self-closing dampers are intentional openings that should be temporarily sealed before the test so they don't inflate envelope leakage readings.

Question 20: Which ASHRAE standard governs minimum ventilation rates for residential buildings and is referenced in RESNET HERS ratings?

ASHRAE 62.2 (Correct answer)
ASHRAE 62.1
ASHRAE 55
ASHRAE 90.2

Correct answer: ASHRAE 62.2

ASHRAE 62.2 sets minimum mechanical and natural ventilation requirements for low-rise residential buildings.

Question 21: A home tests at 6 ACH50. Which HERS reference home air leakage rate would this most closely correspond to for a typical new construction standard?

It meets the ENERGY STAR requirement of 7 ACH50
It equals the IECC 2021 mandatory maximum
It is at the Passive House standard of 0.6 ACH50
It exceeds the typical new construction benchmark of 3 ACH50 (Correct answer)

Correct answer: It exceeds the typical new construction benchmark of 3 ACH50

A common new construction benchmark is 3 ACH50 or less; 6 ACH50 is twice that limit, indicating the home is leakier than typical code expectations.

Question 22: A home has been air-sealed and tightened significantly. What combustion safety issue may arise if no other changes were made?

Higher CO output from sealed-combustion appliances
Lower ambient humidity causing flue liner cracking
Reduced infiltration may starve atmospheric appliances of combustion air, increasing backdrafting risk (Correct answer)
Increased flue gas temperatures

Correct answer: Reduced infiltration may starve atmospheric appliances of combustion air, increasing backdrafting risk

Air sealing reduces the infiltration that previously supplied combustion air to atmospheric appliances, potentially increasing depressurization and backdrafting risk.

Question 23: What does UEF stand for in the context of residential water heaters?

Utility Energy Formula
Uniform Energy Factor (Correct answer)
Unit Efficiency Factor
Universal Energy Factor

Correct answer: Uniform Energy Factor

UEF stands for Uniform Energy Factor, the current DOE metric that replaced the Energy Factor (EF) for measuring water heater efficiency.

Question 24: What does 'effective R-value' account for that nominal R-value does not?

Thermal bridging through framing members and installation defects (Correct answer)
The brand and manufacturing quality of the insulation product
The age and degradation of insulation over a 10-year period
Code-minimum R-values adjusted for climate zone multipliers

Correct answer: Thermal bridging through framing members and installation defects

Effective R-value accounts for the actual whole-assembly thermal performance including heat loss through framing members (thermal bridging) and any insulation installation defects, not just the insulation material alone.

Question 25: Which of the following duct sealing materials is NOT typically approved by RESNET/ACCA for sealing duct leakage in HVAC systems?

UL 181-rated foil tape
Duct mastic
Aerosol sealant (Aeroseal)
Standard cloth duct tape (gray fabric tape) (Correct answer)

Correct answer: Standard cloth duct tape (gray fabric tape)

Standard gray cloth duct tape loses adhesion over time and is not rated for HVAC duct sealing; only mastic, UL 181-rated tape, or approved aerosol sealants meet industry standards.

Question 26: What is the purpose of measuring CO in the undiluted flue gas stream rather than in ambient air during a combustion safety test?

To evaluate combustion quality and detect problems at the source before dilution obscures them (Correct answer)
To determine the heating efficiency of the appliance
To identify refrigerant leaks in split systems
To measure the oxygen content of indoor air

Correct answer: To evaluate combustion quality and detect problems at the source before dilution obscures them

Measuring undiluted flue CO directly evaluates the combustion process quality; ambient readings can be very low even when the appliance is producing dangerous CO concentrations.

Question 27: A home tests at 1,850 CFM50 and has a volume of 12,000 cubic feet. What is the ACH50 value?

6.5 ACH50
15.4 ACH50
9.25 ACH50 (Correct answer)
0.15 ACH50

Correct answer: 9.25 ACH50

ACH50 = (CFM50 × 60) / volume = (1,850 × 60) / 12,000 = 111,000 / 12,000 = 9.25 ACH50.

Question 28: In whole-building energy modeling, what does the term 'internal gains' refer to?

Sensible heat produced by the heating system itself
Heat conducted inward through the building envelope
Solar radiation entering through south-facing windows
Heat generated inside the building by occupants, lighting, and appliances (Correct answer)

Correct answer: Heat generated inside the building by occupants, lighting, and appliances

Internal gains are heat sources within the conditioned space—occupants, lights, cooking, and plug loads—that contribute to the cooling load.

Question 29: When creating a 'Confirmed Rating' for a new home, which of the following inputs MUST be determined by on-site performance testing rather than being taken from construction plans or default values?

The Solar Heat Gain Coefficient (SHGC) of the windows.
The R-value of the wall insulation.
The envelope leakage rate (ACH50). (Correct answer)
The foundation type (slab, crawlspace, or basement).

Correct answer: The envelope leakage rate (ACH50).

A confirmed HERS rating requires on-site inspection and performance testing. While insulation levels and window specs are visually verified from labels and installation, envelope leakage (measured in Air Changes per Hour at 50 Pascals, or ACH50) must be measured with a blower door test. This tested value is a critical, non-negotiable input for an accurate energy model.

Question 30: A building with tight construction and mechanical ventilation exemplifies which principle from ASHRAE 62.2?

Maximum infiltration for indoor air quality
Build loose, ventilate naturally
Balanced pressure at all times
Build tight, ventilate right (Correct answer)

Correct answer: Build tight, ventilate right

ASHRAE 62.2 embraces the 'build tight, ventilate right' approach, using controlled mechanical ventilation instead of uncontrolled air leakage.

Question 31: What does a high ELA (Effective Leakage Area) value indicate about a home?

The home has excellent air sealing
The home has a large equivalent hole size and poor air sealing (Correct answer)
The windows are energy efficient
The HVAC system is oversized

Correct answer: The home has a large equivalent hole size and poor air sealing

A high ELA means the combined leakage pathways are equivalent to a large hole, indicating poor envelope air tightness.

Question 32: Which type of gas appliance venting is most resistant to changes in house pressure conditions?

Atmospheric open-combustion appliance
Natural-draft Type B vent
Sealed-combustion (direct-vent) appliance (Correct answer)
Power-vented appliance with an open combustion chamber

Correct answer: Sealed-combustion (direct-vent) appliance

Sealed-combustion direct-vent appliances draw combustion air from and exhaust directly to the outdoors through dedicated pipes, making them completely unaffected by indoor pressure changes.

Question 33: Under RESNET policy, how many quality assurance file reviews must a provider conduct per rater per year at minimum?

3 reviews per year
1 review per year (Correct answer)
2 reviews per year
5 reviews per year

Correct answer: 1 review per year

RESNET Standards require providers to conduct a minimum of one quality assurance file review per rater per year as part of the ongoing QA process.

Question 34: Which instrument is used to simultaneously measure fan flow and building pressure difference during a blower door test?

Duct blaster only
Infrared camera
Digital manometer connected to the blower door fan and building (Correct answer)
CO2 meter

Correct answer: Digital manometer connected to the blower door fan and building

A digital manometer measures both the pressure difference across the building envelope and the flow through the blower door fan, allowing CFM50 to be calculated.

Question 35: In a hot-humid climate, where should the vapor retarder be placed in a wall assembly?

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

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 36: What is 'wind washing' in an insulated building assembly and why is it problematic?

Air movement through or behind air-permeable insulation that reduces its effective R-value (Correct answer)
Infiltration of wind-driven debris into attic vents
The process of pressure-washing exterior surfaces before applying new cladding
Rain water driven by wind across the exterior cladding surface

Correct answer: Air movement through or behind air-permeable insulation that reduces its effective R-value

Wind washing is air movement through permeable insulation (like batts in a vented cavity), which convectively removes heat and dramatically reduces effective thermal resistance.

Question 37: A HERS rater measures duct leakage to outside at 8% of system airflow. How should this value be entered into the energy model?

As a duct efficiency multiplier between 0 and 1
As leakage to outside only, separate from total leakage (Correct answer)
As total duct leakage including leakage to inside
As an equivalent leakage area in square inches

Correct answer: As leakage to outside only, separate from total leakage

HERS software distinguishes leakage to outside (which affects conditioned air loss) from total duct leakage, and each is entered separately.

Question 38: What factor most affects heating and cooling load in a home?

Window shape
Color of walls
Number of appliances
Insulation and orientation (Correct answer)

Correct answer: Insulation and orientation

Building orientation and insulation values greatly affect heating and cooling demands.

Question 39: A technician replaces an old 80% AFUE furnace with a new 96% AFUE condensing furnace. The old furnace vented through a Type B metal flue. What must be done with the old flue?

Leave it in place and cap it at the top
Repurpose it to vent the water heater if it remains atmospheric, and verify draft performance (Correct answer)
Convert it to a fresh air intake for the new furnace
Remove it entirely regardless of other appliances

Correct answer: Repurpose it to vent the water heater if it remains atmospheric, and verify draft performance

When a furnace is removed from a shared flue, the remaining appliance (e.g., water heater) must be re-evaluated on the now-oversized flue to ensure adequate draft, as orphaning often causes draft problems.

Question 40: Which type of water heater typically achieves the highest UEF rating for residential use?

Propane tankless water heater
Gas storage water heater
Heat pump water heater (Correct answer)
Electric resistance storage water heater

Correct answer: Heat pump water heater

Heat pump water heaters move heat from ambient air rather than generating it, achieving UEF values of 3.0 or higher — far exceeding other residential water heater types.

Question 41: During a HERS pre-drywall inspection, a rater identifies missing insulation in a rim joist cavity. Why is this location particularly important?

RESNET requires rim joist R-value to match wall R-value exactly
Rim joists are a significant thermal bridge and air leakage point at the foundation-to-wall junction (Correct answer)
Rim joists directly affect duct leakage test results
Rim joists are required to be spray-foamed by code

Correct answer: Rim joists are a significant thermal bridge and air leakage point at the foundation-to-wall junction

Rim joists are a major source of both heat loss and air infiltration at the critical junction between the foundation and above-grade framing.

Question 42: How does shading impact energy modeling?

Has no measurable effect
Increases winter heating costs
Raises internal humidity
Reduces cooling demand (Correct answer)

Correct answer: Reduces cooling demand

Shading reduces solar heat gain, which can lower cooling loads in summer months.

Question 43: What is the purpose of the 'Solar Heat Gain Coefficient' (SHGC) of a window?

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

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 44: When performing a spillage test on a natural draft gas furnace that has been off and has a cold vent, at what point during the main burner operation should spillage be assessed?

At 5 minutes. (Correct answer)
After the blower fan has activated.
Immediately upon burner ignition.
At 2 minutes.

Correct answer: At 5 minutes.

For a natural draft appliance with a cold vent, it takes time for the flue to warm up and establish a proper draft. Standard protocols, such as those from BPI, require checking for spillage at 5 minutes of main burner operation to allow sufficient time for the draft to establish. Checking earlier may result in a false failure.

Question 45: The building science mantra "Build Tight, Ventilate Right" refers to which of the following concepts?

Constructing a building with many intentional openings to promote natural air flow.
Sealing the building envelope to control random air leakage and then providing fresh air through a controlled, mechanical ventilation system. (Correct answer)
Ensuring all ventilation ductwork is sealed with mastic, regardless of the building's air tightness.
Using mechanical ventilation as the primary means of air sealing a building envelope.

Correct answer: Sealing the building envelope to control random air leakage and then providing fresh air through a controlled, mechanical ventilation system.

The phrase "Build Tight, Ventilate Right" summarizes a key building science strategy. 'Build Tight' refers to creating a continuous air barrier to minimize or eliminate uncontrolled air leakage (infiltration and exfiltration), which wastes energy and can introduce moisture problems. 'Ventilate Right' means providing a specific, controlled amount of fresh air for occupant health and to manage indoor air pollutants using a mechanical ventilation system, since the natural leakage has been sealed off.

Question 46: Under IECC 2021 for climate zone 5, what is the minimum required attic insulation R-value for a new home?

R-30
R-38
R-49 (Correct answer)
R-60

Correct answer: R-49

IECC 2021 requires a minimum of R-49 attic insulation in climate zone 5.

Question 47: A rater is modeling a home with a ground-source heat pump. Which COP value should be used in the energy model?

The manufacturer's rated COP at standard ARI test conditions
The EER rating converted to COP using the formula EER/3.412
The site-specific COP determined by ground loop entering water temperature and manufacturer performance data (Correct answer)
A default COP of 3.0 as specified in ANSI/RESNET/ICC 301 for all ground-source systems

Correct answer: The site-specific COP determined by ground loop entering water temperature and manufacturer performance data

Ground-source heat pump performance varies with entering water temperature, so the model should use manufacturer performance data matched to the site's ground loop conditions.

Question 48: 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 49: When a HERS rater inputs conditioned floor area into the software, what spaces should be included?

All floors of the home including the garage and unfinished basement
Exterior decks and porches if they are enclosed
Only heated areas above grade with finished flooring
All space within the thermal boundary that is heated or cooled (Correct answer)

Correct answer: All space within the thermal boundary that is heated or cooled

Conditioned floor area includes all space within the thermal and pressure boundary that is intentionally heated or cooled, regardless of finish or grade level.

Question 50: In the context of HERS ratings, what is 'source energy' and how does it differ from 'site energy'?

Site energy is measured at the home; source energy accounts for generation and transmission losses back at the power plant (Correct answer)
They are identical metrics measured at different time intervals
Source energy applies only to on-site renewables; site energy covers grid electricity
Source energy is the energy delivered to the home meter; site energy includes transmission losses

Correct answer: Site energy is measured at the home; source energy accounts for generation and transmission losses back at the power plant

Site energy is measured at the meter, while source energy traces consumption back through generation and transmission, using fuel-specific site-to-source multipliers.

Question 51: During duct leakage testing, why is it important to seal all supply and return grilles before testing?

To comply with OSHA confined space rules
To prevent dust from entering the duct system
To increase duct pressure above 25 Pa
To isolate duct leakage from building envelope leakage (Correct answer)

Correct answer: To isolate duct leakage from building envelope leakage

Sealing grilles ensures that airflow measured by the duct blaster represents only leakage through duct seams and connections, not intentional supply/return openings.

Question 52: 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 53: When testing a home's air barrier continuity during a blower door test, a rater uses smoke or a thermal camera. What does a significant temperature differential at an electrical outlet on an exterior wall indicate?

Air is leaking through the outlet from the exterior or wall cavity (Correct answer)
The outlet is correctly sealed with an insulating foam gasket
The HVAC system is pressurizing the wall cavity
The insulation behind the outlet has higher than expected R-value

Correct answer: Air is leaking through the outlet from the exterior or wall cavity

A temperature differential at an exterior outlet during a blower door test indicates air infiltration through the outlet box from the unconditioned wall cavity or exterior.

Question 54: Which climate-related factor most influences whether a HERS rater recommends a vented or unvented attic assembly?

The local wind speed and prevailing wind direction
The climate zone, humidity levels, and roof geometry (Correct answer)
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 55: Which area of a home typically accounts for the greatest air leakage in standard U.S. construction according to blower door diagnostic studies?

Exterior wall sheathing seams
Foundation sill plate
Window and door frames
Top plates and ceiling penetrations (Correct answer)

Correct answer: Top plates and ceiling penetrations

Top plates and ceiling penetrations (can lights, plumbing, wiring) are the largest source of air leakage in most U.S. homes.

Question 56: In a duct leakage test, what does a very low CFM25 out reading (near zero) with a relatively high CFM25 total reading suggest?

The duct system has significant leaks, all within the conditioned space (Correct answer)
The duct system has no leaks at all
The home fails ENERGY STAR duct criteria
The blower door fan is malfunctioning

Correct answer: The duct system has significant leaks, all within the conditioned space

High total leakage with near-zero outside leakage means ducts are leaking significantly but all the leakage goes into conditioned space, not to unconditioned areas.

Question 57: What is the minimum HSPF rating required for an air-source heat pump to qualify as high-efficiency?

10.0
6.8
7.7
8.2 (Correct answer)

Correct answer: 8.2

An HSPF (Heating Seasonal Performance Factor) of 8.2 or higher qualifies an air-source heat pump as high-efficiency.

Question 58: What is the primary purpose of performing a blower door test with the HVAC system in its normal operating configuration during a diagnostic test (not a rating test)?

To satisfy RESNET rating protocol
To verify that ACH50 is below 3
To measure duct leakage to outside using the Delta Q method (Correct answer)
To calibrate the blower door fan

Correct answer: To measure duct leakage to outside using the Delta Q method

Running the HVAC system during a diagnostic blower door test enables the Delta Q method, which estimates duct leakage to outside based on the change in house pressure with the system on versus off.

Question 59: A HERS Rater, who also owns a window replacement company, performs a rating on a home and recommends upgrading the windows. According to the RESNET Code of Ethics, which of the following actions is required if the rater wishes to bid on the window replacement work?

The rater must disclose the potential conflict of interest in writing to the client. (Correct answer)
The rater must get pre-approval from their Quality Assurance Provider before submitting a bid.
The rater must offer the homeowner a discount on the rating if their company is hired for the window replacement.
The rater is prohibited from bidding on any work they recommend as part of a HERS rating.

Correct answer: The rater must disclose the potential conflict of interest in writing to the client.

The RESNET Code of Ethics emphasizes objectivity, neutrality, and transparency. It requires that certified individuals and accredited providers disclose any potential conflicts of interest. While not prohibiting the work, the rater has an ethical obligation to inform the client in writing of their financial interest in the recommended work to ensure the client can make an informed decision.

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.

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120 min

Time Limit

73%

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