CEA Energy Modeling & Simulation Tools 4

Question 1

In EnergyPlus, what is the function of the 'Output:Meter' object?

Accepted Answer

It reports aggregated energy consumption for specified fuel types and end uses

Answer

Output:Meter objects in EnergyPlus aggregate and report energy consumption by fuel type and end-use category (e.g., cooling electricity, heating gas) at user-specified intervals.

Question 2

Which weather file format is natively used by EnergyPlus for annual energy simulations?

Accepted Answer

EPW (.epw)

Answer

EnergyPlus uses the EnergyPlus Weather (.epw) format, which contains hourly typical meteorological year data including temperature, humidity, solar radiation, and wind.

Question 3

What does 'source energy' represent compared to 'site energy' in building performance analysis?

Accepted Answer

Source energy includes transmission and generation losses; site energy is what enters the building

Answer

Source energy accounts for all energy consumed upstream (power plant generation losses, transmission losses) to deliver one unit of site energy, making it a more comprehensive comparison metric.

Question 4

In a building energy model, how is 'internal heat gain' from lighting typically calculated?

Accepted Answer

Wattage × lighting power density × zone floor area × schedule fraction

Answer

Lighting heat gain is computed as installed watts (LPD × area) multiplied by the hourly schedule fraction, which determines the fraction of rated power in use at each hour.

Question 5

What is the primary advantage of using EnergyPlus over simplified degree-day methods for energy estimation?

Accepted Answer

EnergyPlus models dynamic system interactions, part-load equipment behavior, and hourly weather simultaneously

Answer

EnergyPlus performs full hourly simulation capturing HVAC system controls, equipment part-load curves, and thermal mass interactions that simplified degree-day methods cannot represent.

(CEA) Certified Energy Analyst Practice Test

(CEA) Certified Energy Analyst Practice Test

CEA Energy Modeling & Simulation Tools 4