HVAC System Evaluation Flashcards
7 cards from real HERS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 HVAC System Evaluation flashcards as text
What is the HERS Index score that represents a home meeting the minimum requirements of the 2006 IECC (the RESNET Reference Home baseline)?
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.
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?
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.
A home has a mini-split heat pump serving a finished basement addition. For HERS rating purposes, how is this supplemental system typically treated?
Answer: It is modeled as part of the rated home's total HVAC energy consumption
All mechanical systems serving conditioned space, including supplemental mini-splits, are included in the HERS energy model as part of the home's total energy consumption.
What is the primary reason RESNET requires duct systems to be tested at 25 Pascals (CFM25) rather than at operating pressure?
Answer: CFM25 provides a standardized, repeatable test condition independent of actual system pressure
Testing at a standardized 25 Pascals ensures results are consistent and comparable across different homes and systems, regardless of actual operating conditions.
When evaluating combustion safety for an atmospherically vented gas water heater in a mechanical room, a HERS rater should be concerned about which condition?
Answer: Negative pressure in the mechanical room causing backdrafting of combustion gases
Negative pressure in a mechanical room (caused by exhaust fans, tight construction, or competing appliances) can cause a naturally drafting water heater to backdraft combustion gases indoors.
A HERS rater confirms a heat pump has a Heating Seasonal Performance Factor 2 (HSPF2) of 9.5. What does the '2' suffix in HSPF2 signify?
Answer: It uses an updated test procedure (M1) with higher external static pressure than the original HSPF test
HSPF2 uses the updated DOE test procedure (M1) with higher external static pressure than the original HSPF test, generally resulting in lower numerical ratings that more accurately reflect real-world performance.
Under RESNET's sampling protocol, if a rater is rating a subdivision using the rating sampling plan, what is required for the first home in a subdivision sampled group?
Answer: The first home must receive a full HERS rating with all required inspections and tests
RESNET's sampling protocol requires that the first home in each sampled group receive a complete, fully verified HERS rating to establish the baseline for the group.