Energy Modeling & Simulation Tools Flashcards
7 cards from real CEA 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 & Simulation Tools flashcards as text
In EnergyPlus, what does the 'DesignDay' object primarily define?
Answer: Peak outdoor conditions used for HVAC sizing calculations
DesignDay objects in EnergyPlus specify extreme weather conditions (temperature, humidity, solar) used to size HVAC equipment at peak load.
Which simulation time step setting in EnergyPlus provides the highest temporal resolution for HVAC system interactions?
Answer: 6 minutes
EnergyPlus supports time steps down to 6 minutes (10 steps per hour), providing the finest resolution for capturing fast-changing HVAC dynamics.
When calibrating a building energy model to measured utility data, what statistical metric is recommended by ASHRAE Guideline 14?
Answer: CV(RMSE) and NMBE
ASHRAE Guideline 14 requires both CV(RMSE) ≤15% monthly and NMBE ≤5% monthly for calibrated simulation acceptance.
In eQUEST, what is the primary purpose of the 'Wizard' interface compared to the 'Detailed Interface'?
Answer: Wizard guides users through simplified inputs for quick baseline models
eQUEST's Wizard walks users through a streamlined question-based setup to rapidly create a baseline building model before refinement in the Detailed Interface.
What does the term 'thermal mass' represent in building energy simulation?
Answer: The capacity of materials to store and release heat over time
Thermal mass refers to a material's ability to absorb, store, and slowly release heat, which can shift peak loads and reduce temperature swings.
In OpenStudio, which file format contains the detailed building model data used by the EnergyPlus simulation engine?
Answer: .idf (Input Data File)
OpenStudio's .osm file is translated into an EnergyPlus .idf file, which is the actual input format read by the EnergyPlus simulation engine.
What is the significance of the 'infiltration' input in a building energy model?
Answer: It accounts for uncontrolled air leakage through the building envelope
Infiltration inputs model unintentional air leakage through cracks and gaps in the envelope, which affects both heating/cooling loads and indoor air quality.