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 purpose of the 'quality assurance' (QA) requirement in RESNET's rater certification program?
Answer: To verify that ratings are being conducted accurately and consistently by certified raters
RESNET QA requirements ensure ratings are accurate and consistent by requiring periodic review of raters' work by their Rating Provider.
In energy modeling, 'thermal mass' refers to materials that:
Answer: Store and slowly release thermal energy, moderating temperature swings
Thermal mass materials (concrete, brick, tile) absorb heat during peak periods and release it slowly, reducing temperature fluctuations and peak loads.
A home uses a photovoltaic (PV) system. According to RESNET standards, how is on-site renewable energy generation treated in the HERS Index calculation?
Answer: It can be used to offset the home's energy use and reduce the HERS score
On-site renewable energy generation can be credited in the HERS calculation, reducing the HERS Index and potentially enabling a score below zero (net-zero or net-positive).
Which climate zone designation is used by RESNET energy modeling software, as defined by IECC/ASHRAE?
Answer: IECC Climate Zones 1-8 with marine designations
RESNET and HERS ratings use the IECC/ASHRAE climate zone system (1-8, with A/B/C marine designations) to define heating and cooling loads.
What is 'whole-house mechanical ventilation' and why is it modeled in the HERS energy simulation?
Answer: A system that provides controlled fresh air to the home, which adds ventilation energy use to the model
Whole-house mechanical ventilation systems (HRV, ERV, exhaust fans) provide required fresh air and their energy consumption must be included in the HERS model.
When modeling a home with both electric resistance water heating and a heat pump water heater (HPWH), the rater should input the HPWH's efficiency as:
Answer: EF or UEF (Energy Factor or Uniform Energy Factor)
Water heaters are rated using EF (Energy Factor) or the newer UEF (Uniform Energy Factor), which accounts for standby and cycling losses across test cycles.
A rater discovers that the home's actual wall insulation is R-13 instead of the R-21 specified in the plans. What must the rater do?
Answer: Update the model to R-13 and note the discrepancy in the rating file
The HERS rating must reflect actual as-built conditions, so the rater must update the model to R-13 and document the discrepancy from the original plans.