50 Multiple-Choice Questions on Building Energy and Energy Simulation with Answers
Building energy simulation helps architects, engineers, energy auditors and researchers estimate a building’s energy consumption, thermal performance, indoor comfort and environmental impact before or after construction. The following multiple-choice questions cover building envelopes, heat transfer, HVAC systems, weather data, model calibration, daylighting, thermal comfort and renewable energy. They are useful for GATE, university examinations, competitive examinations and professional training.
Building-Energy Fundamentals
1. What is the primary purpose of building energy simulation?
A. To prepare structural drawings
B. To predict and compare building energy performance
C. To calculate land value
D. To determine soil-bearing capacity
Answer: B. Building energy simulation predicts energy consumption and evaluates alternative designs and operating strategies.
2. What is the SI unit of the thermal transmittance or U-value of a building component?
A. W/m²·K
B. m²·K/W
C. W/m
D. kWh/m²
Answer: A. U-value is expressed in watts per square metre per kelvin.
3. A lower U-value generally indicates:
A. Higher heat transfer
B. Better thermal insulation
C. Higher solar gain
D. Greater air leakage
Answer: B. A lower U-value means that less heat passes through the building component.
4. What is the SI unit of thermal resistance or R-value?
A. W/m²·K
B. m²·K/W
C. W/K
D. J/kg·K
Answer: B. R-value represents resistance to heat flow and is measured in m²·K/W.
5. A wall has an area of 100 m², a U-value of 0.4 W/m²·K and a temperature difference of 10 K. What is the conductive heat-transfer rate?
A. 40 W
B. 100 W
C. 400 W
D. 4,000 W
Answer: C. Heat transfer is calculated as Q = UAΔT = 0.4 × 100 × 10 = 400 W.
6. What does the Solar Heat Gain Coefficient primarily represent?
A. The visible light reflected by glazing
B. The fraction of incident solar radiation admitted through glazing
C. The thermal resistance of a wall
D. The airtightness of a window
Answer: B. SHGC indicates how much incident solar energy enters through a window.
7. A localised path of high heat flow through a building envelope is known as:
A. Thermal bridging
B. Solar shading
C. Night ventilation
D. Heat recovery
Answer: A. Thermal bridges commonly occur at structural connections, slab edges and window frames.
8. Which test is commonly used to measure building airtightness?
A. Slump test
B. Blower-door test
C. Rebound-hammer test
D. Sound-level test
Answer: B. A blower-door test measures air leakage through the building envelope.
9. What does ACH mean in building ventilation analysis?
A. Annual Cooling Hours
B. Air Changes per Hour
C. Average Conductive Heat
D. Air-Conditioning Humidity
Answer: B. ACH indicates how many times the air volume of a space is replaced in one hour.
10. A room has a volume of 300 m³ and receives 600 m³ of air per hour. What is its air-change rate?
A. 0.5 ACH
B. 1 ACH
C. 2 ACH
D. 3 ACH
Answer: C. ACH = 600 ÷ 300 = 2 air changes per hour.
Building Envelope and Passive Design
11. Which shading strategy is generally most effective for reducing unwanted solar heat gain?
A. Internal curtains
B. External shading devices
C. Dark-coloured glass
D. Interior wall insulation
Answer: B. External shading blocks solar radiation before it reaches the glazing.
12. The main purpose of a low-emissivity coating on glazing is to:
A. Increase air leakage
B. Reduce long-wave radiant heat transfer
C. Increase structural strength
D. Absorb moisture
Answer: B. Low-emissivity coatings reduce radiant heat exchange through windows.
13. Thermal mass in a building helps to:
A. Store and release heat over time
B. Increase uncontrolled infiltration
C. Eliminate solar radiation
D. Reduce structural stability
Answer: A. Thermal mass moderates indoor temperature fluctuations by storing and later releasing heat.
14. A cool roof generally has:
A. Low solar reflectance
B. High solar absorptance only
C. High solar reflectance and high thermal emittance
D. High thermal conductivity
Answer: C. Cool roofs reflect a large portion of sunlight and efficiently release absorbed heat.
15. Continuous insulation is useful because it:
A. Increases thermal bridging
B. Reduces heat flow through structural connections
C. Increases solar gain
D. Replaces all ventilation systems
Answer: B. Continuous insulation reduces the effect of thermal bridges in the envelope.
16. What is infiltration?
A. Intentional outdoor-air supply through a mechanical system
B. Uncontrolled movement of outdoor air through cracks and openings
C. Transfer of heat through solid materials
D. Solar radiation passing through glass
Answer: B. Infiltration is unintended air leakage through the building envelope.
17. The stack effect in a building is mainly caused by:
A. Differences in indoor and outdoor air temperature and density
B. Solar reflectance of the roof
C. Artificial lighting
D. Occupant movement
Answer: A. Temperature-related density differences create vertical air movement and pressure differences.
18. Which feature is most closely associated with the urban heat-island effect?
A. Extensive vegetation
B. High-reflectance surfaces
C. Heat-absorbing built surfaces and limited vegetation
D. Low-density rural development
Answer: C. Dense construction, dark surfaces and limited vegetation increase urban temperatures.
19. In the Northern Hemisphere, which strategy can support passive solar heating during winter?
A. South-facing glazing with suitable seasonal shading
B. Large unshaded west-facing glazing
C. Eliminating all thermal mass
D. Increasing roof air leakage
Answer: A. Properly designed south-facing glazing can admit lower-angle winter sunlight.
20. In a hot climate, reducing large unshaded windows on which façade can be especially useful?
A. North façade
B. West façade
C. Underground façade
D. Internal façade
Answer: B. West-facing windows receive intense, low-angle afternoon solar radiation.
Weather Data and Energy Modelling
21. Which file format is widely used to provide hourly weather data to building-energy simulation programs?
A. EPW
B. DOCX
C. MP3
D. DWG only
Answer: A. EnergyPlus Weather, or EPW, files contain hourly climatic information used in simulations.
22. What does a Typical Meteorological Year represent?
A. Weather conditions from one extreme day
B. Representative weather assembled from multiple years of historical data
C. A future climate prediction only
D. Indoor temperature measurements
Answer: B. TMY data represent typical long-term climatic conditions rather than one particular calendar year.
23. In energy modelling, a thermal zone is:
A. A group of spaces assumed to have similar thermal conditions and controls
B. A structural foundation area
C. A parking zone
D. An area without heat transfer
Answer: A. Spaces with similar loads, schedules and temperature controls may be combined into a thermal zone.
24. Reducing the simulation time step generally:
A. Captures short-term changes more accurately but increases computation
B. Eliminates the need for weather data
C. Always reduces model accuracy
D. Removes internal heat gains
Answer: A. Shorter time steps can represent rapidly changing loads and controls more accurately.
25. Which input describes when occupants, lights or equipment are active?
A. Construction schedule
B. Operational schedule
C. Drawing scale
D. Soil profile
Answer: B. Operational schedules define time-dependent occupancy, lighting and equipment use.
26. What is the main purpose of a design-day simulation?
A. Estimating long-term property value
B. Sizing heating and cooling equipment under selected extreme conditions
C. Calculating annual rainfall
D. Preparing architectural renderings
Answer: B. Design days are commonly used to estimate peak heating and cooling requirements.
27. What is a baseline energy model?
A. A reference model used for comparison with proposed improvements
B. A model without weather data
C. A structural-analysis model
D. A model containing only renewable energy
Answer: A. A baseline provides a consistent reference for evaluating energy-saving measures.
28. Parametric analysis involves:
A. Changing selected input values systematically and comparing the results
B. Using only one fixed design
C. Removing all HVAC systems
D. Ignoring building geometry
Answer: A. Parametric analysis evaluates how alternative values or combinations affect performance.
29. Sensitivity analysis is used to determine:
A. Which input variables have the greatest influence on model outputs
B. The colour sensitivity of occupants
C. The market value of construction materials
D. The structural strength of foundations
Answer: A. Sensitivity analysis identifies the inputs that most strongly affect simulation results.
30. Model calibration generally involves:
A. Comparing simulated energy use with measured building data
B. Changing results to match a preferred conclusion
C. Removing occupancy schedules
D. Ignoring utility bills
Answer: A. Calibration adjusts reasonable model inputs so simulated results correspond with measured performance.
31. Which calibration indicator mainly describes the scatter or variability of model errors?
A. COP
B. CV(RMSE)
C. SHGC
D. ACH
Answer: B. The coefficient of variation of the root-mean-square error measures the magnitude and variability of prediction errors.
32. Which metric is commonly used to indicate the average bias between simulated and measured energy data?
A. NMBE
B. U-value
C. PMV
D. R-value
Answer: A. Normalised mean bias error indicates whether a model tends to overpredict or underpredict measured energy use.
33. Building Energy Use Intensity is commonly expressed as:
A. kWh/m²/year
B. W/m
C. kg/m³
D. m/s²
Answer: A. EUI normalises annual energy consumption by the building’s floor area.
34. Which unit is normally used for electrical peak demand?
A. kWh
B. kW
C. kWh/m²/year
D. Kelvin
Answer: B. Kilowatts measure the rate of power demand, while kilowatt-hours measure energy consumption.
35. Computers, printers, appliances and similar devices are generally classified as:
A. Plug loads
B. Envelope loads
C. Ground loads
D. Structural loads
Answer: A. Plug loads represent electricity consumed by equipment connected to electrical outlets.
HVAC Systems and Internal Loads
36. The coefficient of performance of a cooling system is the ratio of:
A. Electrical input to cooling output
B. Useful cooling output to energy input
C. Building area to energy use
D. Airflow to room volume
Answer: B. A higher COP indicates more useful cooling for each unit of energy input.
37. A cooling system has a COP of 3.5 and consumes 10 kW of electrical power. What is its cooling output?
A. 3.5 kW
B. 10 kW
C. 13.5 kW
D. 35 kW
Answer: D. Cooling output = COP × input power = 3.5 × 10 = 35 kW.
38. What does a variable-air-volume system primarily vary?
A. Supply-air quantity
B. Wall thickness
C. Window area
D. Roof reflectance
Answer: A. A VAV system adjusts supply airflow according to the changing thermal load.
39. An air-side economiser reduces mechanical cooling by:
A. Using suitable outdoor air for free cooling
B. Increasing boiler temperature
C. Closing all outdoor-air dampers
D. Increasing lighting power
Answer: A. When outdoor conditions are favourable, outside air can provide part or all of the cooling.
40. What is the purpose of heat recovery in a ventilation system?
A. Transfer energy between exhaust air and incoming outdoor air
B. Increase air leakage
C. Eliminate all fans
D. Increase solar heat gain
Answer: A. Heat-recovery devices reduce ventilation loads by exchanging energy between outgoing and incoming air streams.
41. A thermostat deadband is used to:
A. Prevent frequent switching and simultaneous heating and cooling
B. Increase indoor humidity continuously
C. Eliminate temperature control
D. Increase wall conductivity
Answer: A. A deadband creates a temperature range in which neither heating nor cooling is required.
42. Which load is directly associated with moisture removal from indoor air?
A. Sensible load
B. Latent load
C. Structural load
D. Lighting load
Answer: B. Latent cooling removes moisture, while sensible cooling reduces air temperature.
43. Sensible heat gain mainly causes a change in:
A. Air temperature
B. Moisture content only
C. Building height
D. Atmospheric pressure only
Answer: A. Sensible heat changes temperature without directly changing moisture content.
44. Occupants contribute to building cooling loads through:
A. Sensible and latent heat gains
B. Structural dead loads only
C. Solar reflectance only
D. Groundwater pressure
Answer: A. People release both body heat and moisture into indoor spaces.
Thermal Comfort, Daylighting and Renewable Energy
45. Operative temperature combines the effects of:
A. Air temperature and mean radiant temperature
B. Rainfall and wind direction
C. Solar reflectance and roof colour
D. Building height and floor area
Answer: A. Operative temperature reflects both convective and radiant influences on thermal comfort.
46. Which pair of indices is commonly used to assess thermal comfort?
A. PMV and PPD
B. U-value and R-value
C. COP and EER
D. NMBE and EUI
Answer: A. Predicted Mean Vote and Predicted Percentage Dissatisfied are widely used thermal-comfort indices.
47. Relative humidity is the ratio of:
A. Actual water-vapour pressure to saturation vapour pressure at the same temperature
B. Indoor temperature to outdoor temperature
C. Sensible heat to total floor area
D. Airflow to electrical power
Answer: A. Relative humidity indicates how close the air is to saturation at a given temperature.
48. Daylight autonomy describes:
A. The percentage of occupied time when daylight meets a specified illuminance level
B. The annual output of a photovoltaic system
C. The airtightness of a window
D. The operating time of an air conditioner
Answer: A. Daylight autonomy is an annual measure of useful daylight availability.
49. A building uses 600,000 kWh annually and has a floor area of 5,000 m². What is its Energy Use Intensity?
A. 12 kWh/m²/year
B. 60 kWh/m²/year
C. 120 kWh/m²/year
D. 600 kWh/m²/year
Answer: C. EUI = 600,000 ÷ 5,000 = 120 kWh/m²/year.
50. Which statement best describes an annual net-zero-energy building?
A. It does not use any electrical equipment
B. Its annual renewable energy generation balances its annual energy consumption under the adopted accounting method
C. It operates without occupants
D. It has no windows or ventilation
Answer: B. A net-zero-energy building balances annual energy demand with renewable energy generation according to the applicable boundary and accounting rules.
Conclusion
Building energy simulation enables designers and engineers to assess energy consumption, peak demand, thermal comfort, daylight availability and the effectiveness of energy-conservation measures. A reliable simulation requires accurate geometry, material properties, weather data, occupancy schedules, internal loads and HVAC-system information. These questions provide a foundation for understanding the principles used in tools such as EnergyPlus, DesignBuilder, eQUEST, OpenStudio and similar building-performance simulation platforms.
Keywords: Building Energy, Energy Simulation, Building Performance, EnergyPlus, DesignBuilder, HVAC Simulation, Thermal Comfort, Building Envelope, Energy Efficiency, GATE Quiz
