Energy Modeling & Analysis 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 & Analysis flashcards as text
In REM/Rate or equivalent HERS software, what does the 'reference home' represent?
Answer: A code-minimum home built to the same specifications as the rated home
The reference home is a theoretical code-minimum version of the same home used as the baseline for calculating the HERS Index.
Which parameter has the greatest impact on heating load calculations in cold climates when entering data into HERS software?
Answer: Wall assembly U-factor
In cold climates, wall assembly U-factor directly drives conductive heat loss and dominates heating load calculations.
When modeling a home with a sealed crawlspace in HERS software, how should the crawlspace be categorized?
Answer: Conditioned space with insulated walls
A sealed crawlspace is modeled as conditioned space with insulation on the crawlspace walls rather than the floor above.
A rater enters a furnace with AFUE of 0.96 into HERS software. What does the remaining 4% represent?
Answer: Energy lost to flue gases and jacket losses
AFUE measures seasonal efficiency, and the 4% not converted to useful heat is lost through combustion exhaust and jacket radiation.
Which of the following correctly describes how HERS software handles mechanical ventilation in the energy model?
Answer: Ventilation fan watts and airflow are modeled as an energy load
HERS software models mechanical ventilation by accounting for fan energy consumption and the conditioning load of outdoor air introduced.
What is the purpose of entering an 'as-built' natural gas water heater's Energy Factor (EF) or Uniform Energy Factor (UEF) into HERS software?
Answer: To calculate annual domestic hot water energy consumption
EF/UEF is used by the model to estimate annual energy use for water heating based on efficiency, fuel type, and household demand.
When modeling a home with photovoltaic (PV) panels in HERS software for a HERS Index calculation, what is the standard treatment of PV output?
Answer: PV generation offsets rated home energy use and can reduce the HERS Index below zero
Under RESNET guidelines, on-site PV generation is credited against the home's energy use and can drive the HERS Index to zero or below (a 'zero energy' or 'energy positive' home).