Energy Modeling and 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 and Analysis flashcards as text
In REM/Rate energy modeling software, what does the 'Reference Home' represent?
Answer: A code-minimum baseline home built to IECC specifications used to calculate the HERS Index
The Reference Home is a code-minimum baseline constructed to IECC specifications against which the Rated Home is compared to calculate the HERS Index.
Which input parameter has the greatest single influence on modeled heating energy consumption in a cold climate home?
Answer: Envelope air leakage (ACH50)
Envelope air leakage measured at ACH50 typically dominates heating load in cold climates because infiltration losses scale directly with the temperature difference.
What is the purpose of the 'normalized modified end-use loads' (nMEUL) calculation in HERS rating?
Answer: To adjust end-use loads to account for equipment efficiency and fuel type for Index calculation
nMEUL adjusts each end-use load by equipment efficiency and fuel-specific factors so that the HERS Index fairly represents source energy consumption.
A rater models a home with R-38 attic insulation in a mixed-humid climate. The software shows cooling energy is higher than expected. Which input should be checked first?
Answer: Duct location and leakage values
Ducts located in an unconditioned attic with high leakage dramatically increase cooling loads in mixed-humid climates and are a common modeling oversight.
In energy modeling, what is 'latent load' and why does it matter in humid climates?
Answer: The energy required to remove moisture from indoor air, which drives cooling equipment sizing and runtime
Latent load is the energy needed for dehumidification; in humid climates it can equal or exceed sensible cooling load and significantly affects equipment sizing and energy use.
When entering window properties into energy modeling software, which combination of values most completely describes thermal and solar performance?
Answer: U-factor and solar heat gain coefficient (SHGC)
U-factor captures conductive/convective heat transfer while SHGC captures solar heat gain; together they fully define window energy performance in models.
A HERS rater discovers that the modeled home's mechanical ventilation rate is set to zero in the software. What is the most likely consequence for the HERS Index?
Answer: The Index will be artificially low because ventilation energy is not counted
Omitting mechanical ventilation energy undercounts the home's actual energy use, resulting in an artificially low HERS Index.