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

Question 1: How does water hardness affect water heater efficiency over time?

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

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

Pascals per hour (Pa/hr)
Air Changes per Hour (ACH)
CFM at 25 Pascals (CFM25) (Correct answer)
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 3: When a conflict arises between standard procedures and a unique situation in HVAC System Evaluation, what should a HERS professional prioritize?

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

Correct answer: Safety and ethical obligations while seeking expert consultation

Safety and ethics always take priority in HVAC System Evaluation. 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 4: In energy modeling, what is 'internal gains' referring to?

Solar heat gained through windows
Thermal bridging through structural members
Heat generated by occupants, appliances, and lighting inside the home (Correct answer)
Ground heat transfer through the foundation

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

Internal gains are heat sources within the conditioned space from occupants, lighting, and appliances that reduce heating loads but add to cooling loads.

Question 5: Radon gas mitigation in a residential building is most effectively achieved by installing:

Activated carbon air filtration at the central air handler
An exhaust-only mechanical ventilation system with high airflow
A sub-slab depressurization (SSD) system that vents soil gases to the exterior (Correct answer)
An ERV system with HEPA filtration on the supply airstream

Correct answer: A sub-slab depressurization (SSD) system that vents soil gases to the exterior

Sub-slab depressurization creates negative pressure beneath the foundation slab, preventing radon from entering the living space and exhausting it safely to the outdoors.

Question 6: During a HERS inspection, a rater finds that supply registers are located in the floor of a vented crawlspace. What is the primary energy concern?

The registers may not deliver enough airflow velocity
Floor registers are prohibited by ASHRAE 62.2
The system cannot be balanced properly with floor registers
Ducts in unconditioned crawlspaces are subject to thermal losses and infiltration (Correct answer)

Correct answer: Ducts in unconditioned crawlspaces are subject to thermal losses and infiltration

Ducts running through unconditioned crawlspaces lose conditioned air to thermal conduction and duct leakage, significantly reducing system efficiency.

Question 7: When modeling mechanical ventilation in REM/Rate, what information is required to correctly characterize an HRV?

Only the CFM capacity of the unit
Duct length and filter type
Brand name and model number only
CFM capacity, sensible heat recovery efficiency, and fan watt draw (Correct answer)

Correct answer: CFM capacity, sensible heat recovery efficiency, and fan watt draw

HRV modeling requires airflow rate, sensible recovery efficiency, and fan power consumption to accurately calculate ventilation energy impact.

Question 8: What is the HERS Index score that represents a home meeting the minimum requirements of the 2006 IECC (the RESNET Reference Home baseline)?

85
75
100 (Correct answer)
130

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 9: A rim joist is a common air leakage site in older homes. Which insulation method best addresses both air sealing and thermal performance at the rim joist?

Cellulose blown into the joist bay
Spray foam applied directly to the rim joist (Correct answer)
Rigid foam board with no sealant
Fiberglass batt cut to fit loosely

Correct answer: Spray foam applied directly to the rim joist

Spray foam conforms to irregular surfaces, seals all gaps, and provides insulation in a single step, making it ideal for rim joists.

Question 10: In building science, what does the term 'vapor retarder' (formerly 'vapor barrier') classify?

A material classified by its water vapor permeance (perms) that slows vapor diffusion (Correct answer)
An air barrier material that also resists liquid water infiltration
A drainage layer that redirects liquid water away from the building envelope
A material that completely blocks all moisture movement in both liquid and vapor form

Correct answer: A material classified by its water vapor permeance (perms) that slows vapor diffusion

Vapor retarders are classified by their perm rating: Class I (<0.1 perms), Class II (0.1–1.0 perms), and Class III (1.0–10 perms) per IECC.

Question 11: A HERS rater is evaluating a home with spray foam insulation in the rim joist area. What is the primary benefit of this approach compared to batt insulation alone?

Spray foam adds structural rigidity to the rim joist framing
Spray foam simultaneously provides both insulation and air sealing in a notoriously leaky area (Correct answer)
Spray foam eliminates the need for a vapor retarder in cold climates
Spray foam has a higher R-value per inch than any batt product

Correct answer: Spray foam simultaneously provides both insulation and air sealing in a notoriously leaky area

Rim joists are major air leakage sites; spray foam seals gaps and insulates simultaneously, addressing both thermal and air barrier functions in one application.

Question 12: Why must HERS raters follow the RESNET Code of Ethics?

To boost marketing results
To meet building permit requirements
To reduce software costs
To ensure professionalism and integrity (Correct answer)

Correct answer: To ensure professionalism and integrity

The Code of Ethics ensures raters perform unbiased, professional, and accurate assessments in the public interest.

Question 13: How does risk management apply to daily practice in Energy Modeling Software for Home Energy Rater professionals?

Only through responding to incidents after they occur
Through annual safety audits exclusively
By avoiding high-risk situations entirely
Through proactive identification of potential hazards and implementation of preventive measures (Correct answer)

Correct answer: Through proactive identification of potential hazards and implementation of preventive measures

Effective risk management in Energy Modeling Software requires proactive hazard identification and preventive measures, not just reactive responses. This approach reduces incidents, improves outcomes, and protects both professionals and clients.

Question 14: What does ACH50 measure in residential energy testing?

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

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 15: Which psychrometric property describes the actual moisture content of air independent of its temperature?

Relative humidity
Wet-bulb temperature
Specific humidity (humidity ratio) (Correct answer)
Dew point temperature

Correct answer: Specific humidity (humidity ratio)

Specific humidity (humidity ratio) expresses the mass of water vapor per unit mass of dry air (grains/lb or g/kg), independent of temperature — unlike relative humidity.

Question 16: What is a 'guarded blower door test' (also called a two-fan test) used to measure?

Duct leakage to the outside only
Total building envelope leakage including all zones
Air leakage between two adjacent dwelling units in a multifamily building (Correct answer)
Infiltration through below-grade foundation walls

Correct answer: Air leakage between two adjacent dwelling units in a multifamily building

A guarded (two-fan) blower door test uses one fan in each of two adjacent units to equalize pressure between them, allowing measurement of only the leakage to the outside from each unit in multifamily buildings.

Question 17: Which pipe configuration minimizes hot water wait time and distribution energy losses?

Structured/compact plumbing layout that minimizes pipe length between heater and fixtures (Correct answer)
Trunk-and-branch system with a single large main line
Recirculation loop with a continuous pump running 24/7
Home-run manifold with dedicated lines to each fixture

Correct answer: Structured/compact plumbing layout that minimizes pipe length between heater and fixtures

A structured plumbing layout that minimizes total pipe length between the water heater and fixtures reduces both the wait time for hot water and the heat lost to the surrounding structure.

Question 18: Which standard provides the test method for measuring air leakage of building envelopes using a blower door?

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

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 19: How does risk management apply to daily practice in HVAC System Evaluation for Home Energy Rater professionals?

Only through responding to incidents after they occur
Through proactive identification of potential hazards and implementation of preventive measures (Correct answer)
By avoiding high-risk situations entirely
Through annual safety audits exclusively

Correct answer: Through proactive identification of potential hazards and implementation of preventive measures

Effective risk management in HVAC System Evaluation requires proactive hazard identification and preventive measures, not just reactive responses. This approach reduces incidents, improves outcomes, and protects both professionals and clients.

Question 20: Which standard of practice is MOST important for ensuring quality in Building Envelope & Insulation?

Minimizing documentation to focus on practical work
Following evidence-based protocols while adapting to specific circumstances (Correct answer)
Using the most advanced technology available regardless of need
Strictly adhering to the same procedure in every situation

Correct answer: Following evidence-based protocols while adapting to specific circumstances

Evidence-based protocols provide a foundation of proven practices, but effective Home Energy Rater professionals must also adapt their approach based on specific circumstances and individual case needs within Building Envelope & Insulation.

Question 21: Which mechanism is responsible for the majority of heat transfer through a well-sealed, well-insulated attic floor on a cold winter night?

Air leakage past the insulation
Conduction through the insulation material (Correct answer)
Convection through the insulation fibers
Radiation from the ceiling surface to the cold attic floor

Correct answer: Conduction through the insulation material

Conduction through the insulation material is the dominant heat transfer mechanism in a properly sealed and installed fibrous insulation layer.

Question 22: Which of the following conditions would cause a blower door test to produce an artificially low (better) result?

A gas fireplace with the damper open
An attic hatch that is uninsulated but sealed with tape for the test
Open interior doors between conditioned zones
Testing in high wind conditions (Correct answer)

Correct answer: Testing in high wind conditions

High exterior wind creates positive or negative pressure on the building that interferes with the blower door reading, often producing artificially lower leakage values on the windward side.

Question 23: What HERS Index score must a home achieve to qualify for the ENERGY STAR Certified Homes Version 3.2 program (new construction)?

HERS 60 or below
Any score below 100
HERS 45 or below
HERS 57 or below depending on climate zone (Correct answer)

Correct answer: HERS 57 or below depending on climate zone

ENERGY STAR Certified Homes Version 3.2 requires a HERS Index of 57 or below, with the exact threshold varying by climate zone.

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

Thermal bridging through framing members (Correct answer)
R-value at different outdoor temperatures
Insulation thickness only
Material cost and installation labor

Correct answer: Thermal bridging through framing members

Effective R-value accounts for the reduced whole-assembly thermal resistance caused by thermal bridging through studs, joists, and other framing elements.

Question 25: What is the standard test pressure used for blower door testing when collecting data for HERS ratings?

100 Pascals
75 Pascals
50 Pascals (Correct answer)
25 Pascals

Correct answer: 50 Pascals

HERS ratings use 50 Pascals (Pa) as the standard test pressure for blower door tests to measure envelope airtightness.

Question 26: In HERS rating software, which input primarily determines the modeled sensible heat ratio (SHR) of a cooling coil?

Duct leakage to outside
Equipment rated capacity and local design humidity conditions (Correct answer)
Supply air temperature and duct R-value
Thermostat setpoint and infiltration rate

Correct answer: Equipment rated capacity and local design humidity conditions

The modeled SHR is determined by the equipment's rated performance and local design conditions (temperature and humidity) used in the HERS simulation.

Question 27: Which building science concept explains why a house can have both high insulation levels and still experience significant heat loss?

Modern insulation materials lose effectiveness within 5 years of installation
Air leakage can bypass insulation, making airtightness equally important as insulation (Correct answer)
Over-insulation causes thermal bridging through the excess insulation material
High insulation always prevents all significant heat loss regardless of other factors

Correct answer: Air leakage can bypass insulation, making airtightness equally important as insulation

Even high R-value insulation is ineffective if air leaks bypass it — air sealing and insulation must work together for energy-efficient performance.

Question 28: Which metric is used by the HERS Index to compare the rated home's water heating energy use against the reference home?

The ratio of actual gallons consumed to reference gallons
The water heater's UEF divided by the reference EF
The number of fixtures served divided by the pipe length in feet
Annual water heating energy consumption in kBtu/yr calculated by the rating software (Correct answer)

Correct answer: Annual water heating energy consumption in kBtu/yr calculated by the rating software

HERS software calculates annual water heating energy in kBtu/yr for both the rated home and the reference home, and the ratio contributes proportionally to the overall HERS Index score.

Question 29: A solar water heating system's 'solar fraction' refers to:

The proportion of total annual water heating energy supplied by solar energy (Correct answer)
The percentage of the collector area exposed to direct sunlight
The fraction of the day during which solar radiation exceeds 1,000 W/m²
The ratio of collector tilt angle to local latitude

Correct answer: The proportion of total annual water heating energy supplied by solar energy

Solar fraction is the percentage of a home's annual domestic hot water energy demand met by the solar thermal system, with the remainder supplied by a backup conventional heater.

Question 30: When a conflict arises between standard procedures and a unique situation in Water Heating Efficiency, what should a HERS professional prioritize?

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

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 31: What documentation practice is considered essential in Building Envelope & Insulation within the Home Energy Rater field?

Completing all documentation at the end of the workday
Only documenting unusual events or complications
Using shorthand notes that can be expanded later if needed
Recording actions, observations, and outcomes in real-time or as close to the event as possible (Correct answer)

Correct answer: Recording actions, observations, and outcomes in real-time or as close to the event as possible

Real-time or near-real-time documentation in Building Envelope & Insulation ensures accuracy, provides a contemporaneous record, and is considered the gold standard for professional accountability and legal defensibility.

Question 32: A home has a conditioned floor area of 2,400 sq ft and an unconditioned garage. How should the garage be modeled in HERS software?

Model the garage as an unconditioned adjacent space with the shared wall as part of the thermal envelope (Correct answer)
Average the garage temperature with outdoor conditions for a blended boundary
Include the garage in the conditioned floor area calculation
Ignore the garage entirely since it has no HVAC system

Correct answer: Model the garage as an unconditioned adjacent space with the shared wall as part of the thermal envelope

An unconditioned garage is modeled as an adjacent unconditioned space, with the shared wall, ceiling, or floor treated as part of the home's thermal boundary.

Question 33: In building science, what does 'hygrothermal analysis' evaluate?

The energy efficiency of HVAC equipment under high humidity conditions
The combined heat and moisture movement through building assemblies over time (Correct answer)
The acoustic performance of assemblies in humid environments
The structural load-bearing capacity of a wall under thermal expansion

Correct answer: The combined heat and moisture movement through building assemblies over time

Hygrothermal analysis models both heat (hygro = moisture, thermal = heat) transport simultaneously to predict condensation risk and durability in assemblies.

Question 34: When a conflict arises between standard procedures and a unique situation in Building Envelope & Insulation, what should a HERS professional prioritize?

The preference of the client or stakeholder
The most cost-effective solution available
Strict adherence to written procedures without exception
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 35: Which ventilation standard is referenced in RESNET guidelines to determine whole-house mechanical ventilation requirements for HERS ratings?

EPA Indoor Air Quality Guide
ACCA Manual Q
ASHRAE 90.1
ASHRAE 62.2 (Correct answer)

Correct answer: ASHRAE 62.2

ASHRAE 62.2 'Ventilation and Acceptable Indoor Air Quality in Residential Buildings' is the referenced standard for whole-house mechanical ventilation in HERS ratings.

Question 36: In a mixed-humid climate, what is the primary moisture concern during summer months?

Warm humid outdoor air infiltrating and condensing on air-conditioned surfaces (Correct answer)
Vapor diffusion from the soil through the slab
Condensation on cold water pipes only
Ice damming on the roof

Correct answer: Warm humid outdoor air infiltrating and condensing on air-conditioned surfaces

In mixed-humid climates, warm humid outdoor air infiltrating a cooled building can condense on surfaces below the dew point, causing moisture damage.

Question 37: A rater discovers that the installed attic insulation is R-30 instead of the specified R-49. How does this affect the HERS score?

The HERS score improves because R-30 allows better natural ventilation
The HERS score will be lower (better) because less insulation is cheaper
The HERS score will be higher (worse) because heat loss through the attic increases (Correct answer)
The HERS score is unaffected because attic insulation is not modeled

Correct answer: The HERS score will be higher (worse) because heat loss through the attic increases

Less insulation than specified increases heat transfer through the attic, raising heating and cooling energy loads and resulting in a higher (worse) HERS Index score.

Question 38: Why does the location of a water heater within a home affect its overall system efficiency?

Unconditioned locations such as garages or attics expose the tank to greater temperature differentials, increasing standby losses (Correct answer)
The location determines the UEF test category used by the manufacturer
Building codes require water heaters to be in conditioned spaces only
Water heaters in conditioned spaces are prohibited by most energy codes due to combustion air requirements

Correct answer: Unconditioned locations such as garages or attics expose the tank to greater temperature differentials, increasing standby losses

A water heater in an unconditioned garage or attic faces larger temperature differences between the stored water and the surroundings, which drives greater heat loss through the tank walls and connected piping.

Question 39: Under ENERGY STAR criteria, what minimum UEF must a residential electric storage water heater (55+ gallons) achieve?

1.5
3.5
2.0
2.74 (Correct answer)

Correct answer: 2.74

ENERGY STAR requires electric storage water heaters with capacities of 55 gallons or more to achieve a UEF of at least 2.74, which effectively mandates heat pump technology at that size.

Question 40: During a Qto test using the pressure-matching method, what pressure is the house envelope brought to?

0 Pascals (neutral pressure relative to outdoors)
Positive 50 Pascals to stop infiltration
−50 Pascals (standard blower door pressure)
The same pressure as the duct system (typically 25 Pa) (Correct answer)

Correct answer: The same pressure as the duct system (typically 25 Pa)

In pressure matching, a blower door brings the house to the same pressure as the duct system so that no net airflow exists between house and ducts, isolating only leakage to outside.

Question 41: Which of the following is NOT a valid method to verify that all registers are properly sealed before a duct leakage test?

Checking pressure at each register with a digital manometer (Correct answer)
Visual inspection of each register cover for tape gaps
Using theatrical smoke to detect airflow at sealed registers
Walking the home while the Duct Blaster runs at low pressure to feel for airflow

Correct answer: Checking pressure at each register with a digital manometer

Checking pressure at each register with a manometer measures static pressure, not whether the register is physically sealed against airflow leakage during the test.

Question 42: Which component of a home helps reduce heat loss through the roof?

Attic insulation (Correct answer)
Drywall
Vapor retarder
Radiant barrier

Correct answer: Attic insulation

Attic insulation reduces conductive and convective heat loss, improving energy efficiency.

Question 43: What is the PRIMARY purpose of continuing education requirements in Duct Leakage Testing for HERS professionals?

Earning additional credentials for career advancement
Fulfilling mandatory regulatory requirements only
Maintaining current knowledge and competency as the field evolves (Correct answer)
Networking with other professionals in the field

Correct answer: Maintaining current knowledge and competency as the field evolves

Continuing education in Duct Leakage Testing ensures professionals maintain current knowledge and skills as standards, technologies, and best practices evolve in the Home Energy Rater field.

Question 44: 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)
Using air pressure to test insulation continuity
The process of removing moisture from wet insulation using forced air
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 45: What is the primary advantage of a demand (tankless) water heater over a storage water heater?

It eliminates standby heat losses because it heats water only when needed (Correct answer)
It requires no venting when installed indoors
It delivers water at higher pressure
It can supply unlimited hot water at any flow rate

Correct answer: It eliminates standby heat losses because it heats water only when needed

Tankless water heaters eliminate standby losses entirely because they heat water on demand and do not maintain a stored volume at setpoint temperature between uses.

Question 46: Which RESNET standard governs the accreditation of Home Energy Rating System (HERS) software tools?

RESNET Chapter 2
RESNET Publication 002-2006
ANSI/RESNET/ICC 301 (Correct answer)
RESNET Chapter 3

Correct answer: ANSI/RESNET/ICC 301

ANSI/RESNET/ICC Standard 301 establishes the methods and requirements for rating software accreditation used in HERS ratings.

Question 47: When entering duct system data in REM/Rate, which parameter most directly affects duct leakage modeling?

Duct leakage to outside (CFM25out) (Correct answer)
Duct insulation R-value
Duct material type (flex vs. sheet metal)
Total duct surface area

Correct answer: Duct leakage to outside (CFM25out)

Duct leakage to outside (CFM25out) directly impacts the energy penalty assigned to the duct system in the energy model.

Question 48: What is the purpose of quality assurance reviews in the HERS rating process?

To increase rater income
To promote rater independence
To verify compliance with standards (Correct answer)
To ensure energy savings for all homes

Correct answer: To verify compliance with standards

QA reviews help maintain consistency and accuracy in ratings and ensure compliance with RESNET standards.

Question 49: When insulating a cathedral ceiling without a vented air space, which approach is code-compliant?

Standard fiberglass batts only
No insulation is needed in cathedral ceilings
Vented assembly using batt insulation only
Unvented assembly using air-impermeable insulation meeting IRC requirements (Correct answer)

Correct answer: Unvented assembly using air-impermeable insulation meeting IRC requirements

Unvented cathedral ceilings require air-impermeable insulation (such as spray foam) meeting minimum R-value requirements per IRC Table R806.5.

Question 50: 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?

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

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 51: 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 zero duct leakage to outside
No, 2021 IECC requires ≤4 CFM25 per 100 sq ft to outside (Correct answer)
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 52: Why is mastic sealant generally preferred over standard duct tape for sealing duct leaks?

Mastic is cheaper and easier to apply in tight spaces
Mastic provides greater R-value to the duct surface
Mastic remains flexible and durable, while duct tape adhesive degrades over time (Correct answer)
Mastic can be applied to live pressurized duct systems safely

Correct answer: Mastic remains flexible and durable, while duct tape adhesive degrades over time

Mastic sealant maintains a durable, flexible seal over years of thermal cycling, whereas standard duct tape adhesive dries out and fails, allowing leaks to reopen.

Question 53: What is the role of climate data (TMY files) in HERS energy simulation software?

They provide hourly weather data (temperature, solar, humidity) that drives the annual energy simulation (Correct answer)
They are optional inputs that improve but are not required for HERS calculations
They determine the IECC climate zone for code compliance only
They set the utility rate schedule for each billing period

Correct answer: They provide hourly weather data (temperature, solar, humidity) that drives the annual energy simulation

Typical Meteorological Year (TMY) files provide the 8,760-hour annual weather dataset the simulation engine uses to calculate hourly heating, cooling, and solar interactions.

Question 54: In hot-humid climates, which vapor control strategy is generally recommended for wall assemblies?

Use vapor-open assemblies on both sides that allow drying to the interior and exterior (Correct answer)
Apply a vapor-impermeable coating to the exterior of the wall cladding
Install a Class I vapor retarder (polyethylene) on the interior side of the wall
Install a Class I vapor retarder on the exterior side of the wall sheathing

Correct answer: Use vapor-open assemblies on both sides that allow drying to the interior and exterior

In hot-humid climates, walls should be able to dry to either the interior or exterior; trapping moisture with vapor retarders on either side causes problems.

Question 55: In RESNET standards, what is the primary purpose of a blower door test for the building envelope?

Verify window U-factor compliance
Test duct system tightness
Quantify air leakage through the building shell (Correct answer)
Measure HVAC system efficiency

Correct answer: Quantify air leakage through the building shell

A blower door test depressurizes the home to measure air leakage (ACH50 or CFM50) through the building shell.

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.

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120 min

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73%

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