1. GSB Library Atrium Analysis
John Brooks
Richard Jones
Reid Senescu
Min Jae Suh
Matt Yamasaki

2. Options
Base
No Basement Skylights
Alternate
Basement Skylights

3. Options
Base
No Basement Skylights
Alternate
Basement Skylights

4. Potential Advantages of Skylight
Plus
Minus
Structure
None expected
Other beams bigger.
Larger lateral deflections.
More complex gravity framing
Energy
More natural ventilation, less cooling load
Bigger temp. difference between bottom and top of library
Less insulation, could create more heating/cooling load
Lighting
More daylighting, .less energy
Potential glare, sunshine on books
Acoustics
Louder, less sound absorbing material
CFD
Nat. Ventilation better in the summer
Airflow from doors could decrease comfort in winter
Cost
Lower life cycle cost
Higher first cost, because of less homogenous design
Schedule
Added scope, longer duration

5. Outline Structure Lighting Acoustics Schedule, 4D Cost Energy Analysis
CFD
Sample Money Slide
Challenges and Resolutions
For each tool:
Assumptions
Metrics
Results 

6. Static Load Conditions
Dead Load
Live Load
Earthquake
IBC 2006: Inputs are fixed.
Wind
ASCE 7-02 Wind Loading
Applied to all area objects
Wind speed = 100 mph
Unknown Inputs: importance factor, exposure type, topographical factor, gust factor, directionality factor

7. Model Analysis Analysis Goal Analysis Parameter
Determine maximum moments & deflections under given loading conditions
Determine demand capacity ratios for all members
Analysis Parameter
Dimensions of members
Joints: Releases
Materials
Loads: Load combinations

8. Revit Structure
Regenerate Revit Architecture model

9. ETABS Import Revit model Correct geometric errors
Define “dummy surfaces”
Define additional load parameters & combinations
Analyze

10. Analysis Result
ETABS generates shear, moment, deflection and demand capacity data on structure.

11. Earthquake Displacements
Displacements in original design due to earthquake are excessive.
Possibly due to invalid inputs. 11 11

12. Design Check
Numerous failures of structural members in original design.
Possibly due to invalid inputs. 12 12

13. Lighting - Occupant Behavior
Occupied 8 AM to 5 PM
Min. Illuminance: 500 lux
Active and Passive light switching and blind use
Manual on/off switch near door
Installed lighting power density 1.5 W/SF

14. Lighting – Analysis Assumptions
Time Step: 30 minutes
Ground Reflectance: 0.2

15. Lighting – Metrics Units Measurement -3 3 Daylighting Aesthetics3
Daylighting Aesthetics
unitless
My opinion
Claustro-phobic ok
beautiful
Lighting Cost
Dollars / SF
Energy
$3410
$1746
$737
Lighting Quality
% of sensors
Continuous Daylight Factor > 40% 0%
40%
90%

16. Skylights provide more light…
Annual Light Exposure (lux hours)
Base
No Basement Skylights
Alternate
Basement Skylights

17. Not much direct light… Alternate Basement Skylights December 21, 2008
December 21, 2008, 2:00 PM

18. Not much direct light… Alternate Basement Skylights
December 21, 2008, 2:00 PM

19. Lighting Results For Base and Alternate:
Total Electric Lighting Energy: 3.5 kWh/SF
Average Office Building Energy: 2.6 kWh/SF
Daylight Autonomy: 0%
% of the year when a minimum illuminance threshold is met by daylight alone
0% of sensors have Daylight Factor > 2%
ratio of internal to external illuminance.
Base
Alternate
% of sensors with Continuous Daylight Autonomy >40% 0%
11%

20. Next Steps For Base and Alternate:
WHY?
For Base and Alternate:
Total Electric Lighting Energy: 3.5 kWh/SF
Average Office Building Energy: 2.6 kWh/SF
Daylight Autonomy: 0%
% of the year when a minimum illuminance threshold is met by daylight alone
0% of sensors have Daylight Factor > 2%
ratio of internal to external illuminance.
WHY?
WHY?
Base
Alternate
% of sensors with Continuous Daylight Autonomy >40% 0%
11%

21. Information Goal Models Metrics
What is a different acoustics after designing 3 skylights on
the ground floor & basement?
(Influence of 3 skylights to the ground floor & basement)
Models
Baseline: Original GSB Atrium
Option: GSB Atrium with 3 skylights on the
ground floor
Metrics
Two different models (Base vs. Option)
Each different volume and surface of models (2,735m³ vs. 5,270m³ ) 21 21

22. Assumption Material Condition (Fixed)
No influence from outside weather and noise 22 22

23. Assumption(Cont) Sound Condition
Setup 1 speaker instead of noise for the each analysis
No influence from existing the upper floors or not
No influence of the components and equipments except
50 clothe-covered chairs
Twice bigger volume due to the skylights in option
Consider only Sabine Algorithm for Reverberation time

24. Base vs. Option Sound Path (Low Frequency: 63Hz) BASE: 21.7ms
OPTION: 18.5ms

25. Base vs. Option(Cont) Sound Path (High Frequency: 16KHz) BASE: 17.4ms
Option: 15.7ms

26. Base vs. Option(Cont)
Base Reverberation Time

27. Base vs. Option(Cont)
Option Reverberation Time

28. Base vs. Option(Cont)
Base Acoustic Response
63Hz: 47ms
16KHz: 47ms

29. Base vs. Option(Cont)
Option Acoustic Response
63Hz: 89ms
16KHz: 95ms

30. Base vs. Option(Cont) Result 63Hz 16KHz Base Option Elapsed Time
21.7ms
18.5ms
Sound Type
Direct/Masked
Base
Option
Elapsed Time
17.4ms
15.7ms
Sound Type
Direct/Masked

31. Base vs. Option(Cont) Result Base Option RT Value 500ms~690ms
Ideal RT Value
800ms~1750ms
1000ms~1900ms
Estimated Decay
63Hz: 47ms
63Hz: 89ms
16KHz: 47ms
16KHz: 95ms

32. Conclusion
The RT of option model is in the ideal pink area, but the RT of base model is below the area.
The volume and surface of base model is easy to absorb the sound rays.
There is no influence by 3 skylights to the basement
3 Skylights change the result a little bit, but make a better acoustic condition at the ground floor.
Better RT result
The base model has a longer elapsed time to completely disappear.
The volume and the surface area bring a big different criteria for ideal condition.
Ideal Pink Area: 800ms~1750ms vs. 1000ms~1900ms

33. For the next step
Simulate the model with several different noise directions.
Figure out the scale of preference about estimated decay time
Find out other metrics to achieve a better result.

34. Costs, Schedule

35. Assumptions Building Explorer is right U.S. Average Building Index ok
Automatically generated schedule ok

36. Results

37. Material Costs

38. Labor Costs $

39. Equipment Costs
$33.82

40. Schedule + 4D
4-Day Duration…

41. Day 1

42. Day 2

43. Day 3

44. Day 4

45. Energy Analysis Goal: To determine energy consumption of building
To determine if natural ventilation will be sufficient

46. Energy Analysis IES Virtual Environment ApacheSim
Simulates natural and mixed ventilation (MacroFlo)
Simulates building loads (ApacheLoad)
Simulates heat loss/gain (ApacheCalc)

47. Energy Analysis Assumptions: Model inputs Simulation
HVAC System: Mixed System w/ natural ventilation
Weather file: Moffett Field, Mountain View, CA
Building type: Library
Building construction: default room system
Thermal condition: Atrium Each Floor
Fluorescent lighting – 1.5W/SF
People 65 from 10am-12am
Simulation
Run period: 1 May to 31 May
Time step: 10 minutes
Report interval: 60 minutes
Preconditioning: 10 days

48. Energy Analysis Results
Carbon Emissions
CO2 emissions – base case
Total monthly emissions – 35,027 lbCO2
CO2 emissions – alternative case
Total monthly emissions – 46,587 lbCO2

49. Energy Analysis Results
Energy Consumption
Energy Consumption – Base case
Monthly total – MMBtu
Energy Consumption – Alternative case
Monthly total – MMBtu

50. Energy Analysis Results
Heating/Cooling Loads
Daily Heating and Cooling Loads – base case
Monthly total – heating: MMBtu; cooling: 0MMBtu
Daily Heating and Cooling Loads - alternative
Monthly total – heating: MMBtu; cooling: MMBtu

51. Energy Analysis Results
Room analysis – Stacks
Peak hourly room loads
Room environmental conditions
Alternative Case
Base Case

52. Energy Analysis Next Step More accurately capture behavior of building
Determine actual operating hours
Determine actual HVAC system
Type, set points, etc
Create more accurate geometry

53. CFD Analysis CFD: Computational Fluid Dynamics
Analysis of fluid flows using numerical methods and algorithms
Simulation of wind tunnel performance

54. CFD Analysis IES Virtual Environment MicroFlo (IES VE)
Numerical simulation of air flow an heat transfer
User definable obstructions
Interoperability with Virtual Environment model

55. CFD Analysis Goals: Determine effects of atrium on airflow in building
Predict occupant comfort
Temperature gradient in rooms
Air velocity

56. CFD Analysis Model inputs: Model outputs:
Boundary Conditions defined during energy analysis
Obstructions and heat generating component
Ex: People, computers, radiators, etc
Model outputs:
Air flow temperature, direction, and velocity
Graphical displays of temperature gradient and air flow properties

57. CFD Analysis Progress Problems with importing gbXml geometry
Inconsistencies developed between Revit and IES

58. CFD Analysis
Next Step
Manipulate Revit model to properly represent geometry in IES
Contact with IES tech support as well as Ben Welle

59. Sample MACDADI Goodness