This document summarizes a presentation on glass curtain walls, including their design, engineering, and performance. It discusses curtain wall systems and components, key performance considerations like structural capacity, water tightness, thermal performance, and testing and construction methods. The presentation provides an overview of stick-built and unitized curtain wall systems, glass retention methods, spandrel panels, transitions between walls and other assemblies, and other glazing systems. It also addresses lab mockup testing, fabrication, storage, transportation, installation, and field testing of curtain walls.

1. Glass Curtain Walls
Design, Engineering, and Performance
Building Enclosure Council ‐ Baltimore
14 June 2016
John A. Jackson, M.Eng, AIA
Simpson, Gumpertz, & Heger

2. Credit(s) earned on completion of
this course will be reported to AIA
CES for AIA members.
Certificates of Completion for both
AIA members and non-AIA
members are available upon
request.
This course is registered with AIA
CES for continuing professional
education. As such, it does not
include content that may be
deemed or construed to be an
approval or endorsement by the
AIA of any material of construction
or any method or manner of
handling, using, distributing, or
dealing in any material or product.
_______________________________________
Questions related to specific materials, methods,
and services will be addressed at the conclusion
of this presentation.

3. This presentation is protected by US and International Copyright laws.
Reproduction, distribution, display and use of the presentation without written
permission of the speaker is prohibited.
Provider Number: J380
Course Number: GLASSCW60
© 2016 Simpson Gumpertz & Heger Inc.
Copyright Materials

4. Curtain Walls

5. Curtain Walls
• Systems
• Performances
• Testing &
Construction

6. Curtain Walls
• Terminology
• Stick-Built
• Unitized
• Glass Retention
• Spandrel Panels
• Transitions
• Other Materials
• Other Glazing Systems
• Systems
• Performances
• Testing &
Construction

7. Terminology
Mullion
Transom
Stack head
Stack sill
Stack joint
Spandrel
panel

8. Stick-Built

9. Stick-Built

10. Stick-Built

11. Stick-Built

12. Stick Built

13. Unitized

14. Unitized

15. Unitized

16. Unitized
wet dry
“chicken head”
outside inside
thermal break
rainscreen
gasket
movement at
stack joint

17. Unitized
wet
dry
outside
inside

18. Unitized

19. Unitized
“chicken head” acts as lateral
restraint for above panel
Anchor bracket
Embed anchor
Above
panel

20. Unitized
Silicone
boot

21. Unitized
“chicken head”
Panel splice
wet
dry
1 panel

22. Capped
(i.e. traditionally glazed)
Glass Retention
Structural Silicone Glazed
(i.e. SSG)

23. Glass-to-Glass
Bolt-Fixing Clamped
Toggle-Fixing
Glass Retention

24. Spandrel Panels

25. Spandrel Panels
Spandrel Glass

26. Spandrel Panels
Shadow Box

27. Spandrel Panels
All Glass

28. Transitions
Perimeter
sealant joint
Flexible membrane
tied into glazing
pocket
Glazing stop
installed on site

29. Transitions
Sealant
Aluminum
plate
Panel hung
from floor
above
Flexible
membrane
glued to
everything

30. Transitions

31. Other Glazing Systems
Punched Windows Ribbon Windows

32. Other Glazing Systems
Window WallStorefront

33. Other Glazing Systems
Glass FinsCables & Rods

34. Other Glazing Systems
Double Skins Free-Form

35. Other Materials
Metal Panel TerracottaStone

36. Curtain Walls
• Structural
• Movement
• Water-tightness
• Airtightness
• Solar Control
• Thermal
• Condensation Assessment
• Ventilation
• Acoustics
• Fire
• Blast
• Access & Maintenance
• Systems
• Performances
• Testing &
Construction

37. Structural
Deflection due to
wind suction
Deflection due to
wind pressure
Framing Deflection
Internal steel
reinforcement

38. Structural
Glass Deflection
Glass Center-
Pane Deflection

39. Movement
• Live Load Deflections
• Wind Load Deflections/Sway
• Seismic Deflections/Sway
• Thermal Movements
• Moisture Movements
• Long-Term Shrinkage
• Differential Settlement
• Superimposed Dead Load Deflections
• Construction Sequencing
• Fabrication Tolerances
• Erection Tolerances
• Dead Load Deflections
• Snow/Rain Load Deflections

40. Movement

41. Movement
Δ
H

42. Water-tightness
Water-tightness:
Provide aluminum curtain wall systems
that do not evidence water penetration
when tested according to ASTM E331
(static) and AAMA 501.1 (dynamic) for
one 15 min. cycle at a minimum
differential static pressure of 20% of the
peak positive wind load design
pressure, but not less than 15 psf.

43. Barrier
(i.e. no provision for drainage within system)
Drained and Ventilated
(i.e. provision for drainage)
WATER
DRAINAGE
Water-tightness

44. Water-tightness
Drainage at Base
(i.e. pressure moderated)
Zone Dammed Drainage
(i.e. pressure equalized)

45. Water-tightness
Continuous two lines of water defense
within system and at transition to adjacent
assemblies.
First Line
Second Line

46. Airtightness
Air Infiltration/Exfiltration:
Provide aluminum glazed
curtain wall systems with
maximum air leakage of
0.06-cfm/sq ft of fixed wall
area when tested according
to ASTM E283 at a
minimum static-air-pressure
differential of 6.24-lbf/sq ft.

47. Airtightness
Continuous air barrier within system and at
transition to adjacent assemblies.
Air barrier

48. Solar Control
Solar Energy:
• Infrared (i.e. Heat Gain)
• Visible (i.e. Light Transmission)
• Ultraviolet (i.e. Material Degradation)

49. Solar Control
Layer1
Layer2
Solar Heat Gain Coefficient (SHGC)
- Total percentage of solar heat energy transmitted through
a material, including energy absorbed and reradiated
- European designation: G-value = SHGC
- Shading Coefficient (SC) is an antiquated term, based on a
standardized glass thickness (SHGC = 0.87 * SC)
- Unit-less Value, ranges from 0 to 1.0
- Typical SHGC of glazing include:
High Performance, Low-E 0.25 – 0.55
1 2 3 4
Typical position of Low-E Coating

50. Solar Control
Solar Heat Gain Coefficient
(SHGC)
Visible Light Transmission
(VLT)
Light to Solar Gain (LSG)
= VLT/SHGC

51. Thermal
1)
2)
3)
U-value of
Glazing System
Center of Glass U-value

52. Thermal
Frame
Edge
(2-1/2”)
Edge
(2-1/2”)
Center
Pane
Center
Pane

53. Thermal
Thermal Barrier
Continuous thermal barrier within
system and at transition to adjacent
assemblies.

54. Condensation Assessment
Interior dew point temperature: 37°F
Interior Temperature: 70°F
Interior Relative Humidity: 30%
Exterior Temperature: 17.3°F
Exterior Wind Speed: 15.3 mph

55. Ventilation

56. Acoustics
• Inside to Outside
• Vertical Flanking (floor-to-floor)
• Horizontal Flanking (across partitions)

57. Fire
UL Tested Edge of Slab
Firesafing Assembly

58. Blast
Peak
Pressure
Initial
pressure
Initial
rebound
Impulse =
area under curve
Approx. Impulse =
area under triangle

59. Access & Maintenance

60. Conflicting Requirements
Thermal Control vs Transparency
High cost Complexity vs Standardisation
Low visual Weight vs Strength
Need for Ventilation & Access vs Weathertightness
Need for Ventilation & Access vs Acoustic control
High quality vs Cost
Complexity vs Fast installation
New technology vs Risk
Architectural Forms vs Maintenance Access

61. Delegated Design
Glazed aluminium curtain wall systems
shall be designed, engineered,
fabricated, and installed by a single-
source curtain wall sub contractor:
• Structural Calculations
• Air and Water Management
• Thermal Calculations
• Condensation Assessment
• Edge of Slab Firesafeing

62. Curtain Walls
• Systems
• Performances
• Testing &
Construction
• Lab Mockup Testing
• Fabrication
• Storage
• Transportation
• Installation
• Field Testing

63. Lab Mockup Testing
Air Infiltration/Exfiltration (ASTM E283) Static Water (ASTM E331)

64. Lab Mockup Testing
Dynamic Water (AAMA 501.1)

65. Lab Mockup Testing
Deflection (ASTM E330) Thermal Cycling/Condensation Assessment
(AAMA 501.5)

66. Lab Mockup Testing
Horizontal Movement (AAMA 501.4) Vertical Movement (AAMA 501.7)

67. Fabrication

68. Fabrication

69. Storage

70. Transportation

71. Installation

72. Installation

73. Installation
Site applied
panel splice

74. Field Testing
Hose Testing (AAMA 501.2) Chamber Air (ASTM E783)
Chamber Water (ASTM E1105)

75. Questions?
John A. Jackson, M.Eng, AIA
Simpson, Gumpertz, & Heger