Energy Modeling & Rating Systems 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 Energy Modeling & Rating Systems flashcards as text
What is the significance of a HERS Index score of 0?
Answer: The home produces as much energy as it consumes on an annual basis (net-zero)
A HERS score of 0 indicates a net-zero energy home, meaning annual on-site energy production equals total annual energy consumption.
In HERS energy modeling, 'infiltration' is typically converted from ACH50 to natural infiltration using which method?
Answer: Divide ACH50 by 10 using the n-factor method
The n-factor (or LBL) method divides the ACH50 value by approximately 10 (range 14-20 depending on climate) to estimate natural infiltration under normal conditions.
Which of the following best describes the role of the 'Rating Provider' in the RESNET certification hierarchy?
Answer: An organization that trains, certifies, and provides QA oversight for individual raters
Rating Providers are RESNET-accredited organizations responsible for training raters, maintaining their certifications, and conducting quality assurance oversight of ratings.
When modeling a raised floor (over unconditioned crawl space), which R-value location is typically entered in the energy model?
Answer: Floor insulation in the floor assembly above the crawl space
For a vented crawl space, insulation is installed in the floor assembly above the crawl, and this R-value is entered as the floor insulation in the energy model.
A homeowner adds a solar water heater after the initial HERS rating is complete. How does this affect the existing HERS certificate?
Answer: A new rating would need to be performed to reflect the change in the HERS score
Post-construction additions that significantly affect energy performance require a new rating and inspection to update the HERS Index and issue a revised certificate.
What does 'ERI' stand for in the context of energy codes that reference HERS-like ratings?
Answer: Energy Rating Index
ERI (Energy Rating Index) is an IECC performance compliance path that uses a HERS-like score to demonstrate code compliance, allowing energy trade-offs between components.
In an energy model, how is a cathedral ceiling with spray foam insulation between rafters typically classified compared to a ventilated attic with batts?
Answer: Cathedral ceilings are modeled as roof assemblies with adjusted U-factors; ventilated attics use ceiling insulation inputs separately
Cathedral ceilings require modeling the complete roof assembly U-factor including framing factors, while ventilated attics model the ceiling insulation separately from the roof deck.