2. CW can be defined based on
Functional relationship
It then refers to the cladding, or enclosure, of a building as something
both separate from and attached to the building's skeletal framework.
Where load bearing walls provide both structure and enclosure, there
can be no curtain wall.
Aesthetic object
metal (as industrialized, mass-produced, streamlined panel); glass (as
transparent or reflective surface, crystalline solid, or harbinger of an
enlightened culture); or metal and glass combined (as woven "fabric,"
or abstract grid).
Mass-produced system
Initially CW are unique and custom made but they became
increasingly common with commercial and institutional buildings
3. What is curtain walling?
E It is a vertical building enclosure which
supports no other load other than its own
weight and the environmental forces which
act upon it. Curtain walls are not intended to
assist in maintaining the structural integrity of
the building.
Net
4. What are the materials used for CW?
E Frame
Aluminum
Steel
Infill – large panels that are inserted
to the CW between mullions
1. Glass – 6mm to 25mm
2. Louvers
3. Stone veneer – granite, marble,
limestone
4. Metal panels – stainless steel,
aluminum plate
Net
5. E
Stick system
1. Prepared and
machined in the
factory and
supplied in knock
down form
2. Economical
3. If correctly
designed, detailed
and installed are
highly reliable
4. Not for fast track
projects
Unitized system
1. Series of factory
assembled frames
with interlocking
mullions and
transoms, used
when there is
expected greater
movement/deflecti
on of the building
2. Provides speed of
installation,
minimal on site
labor, reduces site
sealing
3. More expensive
than stick system
and requires
longer lead time
How is CW installed?
Net
6. What are the design considerations?
E
It must be designed to handle all of the following:
1. Dead load - weight of fixed materials
2. Wind load
3. Seismic load - design the components and anchors that should be able to withstand
75mm floor movement without glass breakage or water leakage
4. Snow load - considered if wall slope is 20-50˚
5. Thermal load - aluminum has high thermal expansion, thus it will expand and contract
at some distance
6. Blast load - blast resistant glass should consist laminated glass which breaks but
doesn’t separate from mullions
7. Infiltration - allowed is 0.6CFM/sq.ft maximum
8. Water penetration – allowed is small amount of controlled water
9. Deflection – at the maximum wind pressure it can be allowed to deflect at L/75 (ex.
12ft floor ht= 144”/75 = 0.82”
10. Insulation – provide 2 or more panels with air space
11. Radiant heat absorption – glass should be tinted
12. Tensile and compressive stress provision – use tempered, annealed glass
Net
7. What are the fundamentals of CW?
E System types
Thermal performance
Moisture protection
Visual
Sound
Back pans
Shadow boxes
Supports
Safety
Maintenance and access
Health and indoor air
quality
Durability and service life
expectancy
Maintainability and
repairability
Sustainability
Net
8. What are the technological
advancements of CW?
E1. Building-integrated photovoltaic – the façade can generate
electricity, provide weather and acoustic insulation
2. Chromatic panel – exterior aluminum cladding and silver
colored glass and glass sheeting covered with reflective film
on the interior provides transparent sunscreen
3. Smart curtain walls – control visible light transmittance by
employing electrochromic or photochromic glass coatings
4. Double – skin systems, which employ a ventilated space
between the inner and outer walls
Net
10. Center for Environmental Science and Technology
Management, Albany, spherical shaped building
with sloped wall which captures renewable energy
while controlling solar heat gain and reducing the
cooling load of the building
Oterprise Square Hong Kong
27-storey with splayed glass
skin, louvers, operable
windows and
horizontal sunscreens
Cité de Refuge: Le
Corbusier, with brise-
soleil added to facade
11. Five Brindleyplace, Birmingham, glazed atrium to
offer natural internal environment with minimal
solar gain through use of automatic blinds & vents
Calakmul, Sta. Fe, Mexico, custom structural
silicone glazed framing and aluminum
panels& pyramidal skylights
12. Getty Center: Richard Meier, metal
panel system
Glass Pavilion: Bruno
Taut, CW was used carry
the concept harbinger of
enlightened culture
Pacific Design Center: Cesar Pelli,
as a sculptural reflective surface
Willis Faber Dumas
Building: Sir Norman
Foster, literally hangs
curtain of
transparent/reflective
glass
