HERS Energy Modeling and Analysis 2

Question 1

In REM/Rate energy modeling software, what does the 'Reference Home' represent?

Accepted Answer

A code-minimum baseline home built to IECC specifications used to calculate the HERS Index

Answer

The Reference Home is a code-minimum baseline constructed to IECC specifications against which the Rated Home is compared to calculate the HERS Index.

Question 2

Which input parameter has the greatest single influence on modeled heating energy consumption in a cold climate home?

Accepted Answer

Envelope air leakage (ACH50)

Answer

Envelope air leakage measured at ACH50 typically dominates heating load in cold climates because infiltration losses scale directly with the temperature difference.

Question 3

What is the purpose of the 'normalized modified end-use loads' (nMEUL) calculation in HERS rating?

Accepted Answer

To adjust end-use loads to account for equipment efficiency and fuel type for Index calculation

Answer

nMEUL adjusts each end-use load by equipment efficiency and fuel-specific factors so that the HERS Index fairly represents source energy consumption.

Question 4

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?

Accepted Answer

Duct location and leakage values

Answer

Ducts located in an unconditioned attic with high leakage dramatically increase cooling loads in mixed-humid climates and are a common modeling oversight.

Question 5

In energy modeling, what is 'latent load' and why does it matter in humid climates?

Accepted Answer

The energy required to remove moisture from indoor air, which drives cooling equipment sizing and runtime

Answer

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.

(HERS) Certified Home Energy Rating System Rater Practice Test

(HERS) Certified Home Energy Rating System Rater Practice Test

HERS Energy Modeling and Analysis 2