HERS Field Inspection & Testing 2 — Questions and Answers
Question 1: When performing a blower door test, at what reference pressure is the airflow typically measured for HERS rating purposes?
- 25 Pascals
- 50 Pascals (Correct answer)
- 75 Pascals
- 100 Pascals
Correct answer: 50 Pascals
Blower door tests for HERS ratings are conducted at 50 Pascals (Pa) of depressurization to standardize results across different homes.
Question 2: A rater measures duct leakage to outside on a new construction home and gets 4.5 CFM25 per 100 sq ft of conditioned floor area. Which ENERGY STAR threshold does this result meet?
- It exceeds the ENERGY STAR limit of 4 CFM25
- It meets the ENERGY STAR Certified Homes limit of 5 CFM25 or less (Correct answer)
- It fails because the limit is 3 CFM25
- It passes only if total duct leakage is also tested
Correct answer: It meets the ENERGY STAR Certified Homes limit of 5 CFM25 or less
ENERGY STAR Certified Homes Version 3.2 requires duct leakage to outside to be ≤4 CFM25 per 100 sq ft of conditioned floor area for most climate zones, but thresholds vary; at 4.5 it would fail the 4 CFM25 limit but context matters.
Question 3: During a field inspection, the rater finds insulation installed with a visible air gap between the insulation batt and the exterior wall sheathing. How should this be rated?
- Grade I — batts are present and adequate
- Grade II — minor defects that reduce performance
- Grade III — substantial defects requiring remediation (Correct answer)
- Not rated — only blown insulation is graded
Correct answer: Grade III — substantial defects requiring remediation
Air gaps between insulation and the sheathing represent a Grade III installation defect because they create thermal bypasses that substantially degrade insulation performance.
Question 4: What is the primary purpose of a duct pressurization test (Duct Blaster) during a HERS field inspection?
- To measure the airtightness of the building envelope
- To quantify air leakage from the duct system (Correct answer)
- To verify static pressure in supply registers
- To measure airflow at each supply outlet
Correct answer: To quantify air leakage from the duct system
A duct pressurization test uses a Duct Blaster to pressurize the duct system and measure the total leakage from supply and return ducts.
Question 5: A HERS rater is inspecting a home with a vented crawl space. Which of the following conditions would be a concern for moisture management during field inspection?
- Ground cover vapor barrier covers 100% of the soil
- Insulation is installed between the floor joists above
- The crawl space vents are open year-round
- Exposed soil has no ground cover vapor barrier (Correct answer)
Correct answer: Exposed soil has no ground cover vapor barrier
Exposed soil in a crawl space without a vapor barrier allows moisture to evaporate into the crawl space, risking mold, rot, and energy loss.
Question 6: When verifying mechanical ventilation during a HERS field inspection, what should the rater measure to confirm adequate whole-house ventilation?
- Thermostat setpoint and run time
- Actual airflow (CFM) compared to the ASHRAE 62.2 required rate (Correct answer)
- Number of exhaust fans in bathrooms
- Filter MERV rating on the air handler
Correct answer: Actual airflow (CFM) compared to the ASHRAE 62.2 required rate
ASHRAE 62.2 defines minimum whole-house ventilation rates, and the rater must measure actual airflow (CFM) to verify the installed system meets those requirements.
Question 7: During a heating system inspection, the rater observes that a gas furnace flue pipe has a visible gap at a joint inside conditioned space. What is the primary concern?
- Reduced AFUE efficiency rating
- Combustion gases may spill into the living space (Correct answer)
- Noise from combustion air intake
- Condensation on the exterior of the flue pipe
Correct answer: Combustion gases may spill into the living space
A gap in a gas furnace flue pipe inside conditioned space can allow dangerous combustion gases, including carbon monoxide, to spill into the living area.
HERS Field Inspection & Testing 2
When performing a blower door test, at what reference pressure is the airflow typically measured for HERS rating purposes?