Page 27 - Magazine Azim Print

In waterproofing the building against Seattle’s rainy climate, Seele designed three levels
WEATHERPROOFING
of defense into the system:
1) the exterior aluminum mullion cap with pre-molded silicone gaskets,
2) insulated glazing panels with flexible butyl tape applied along every joint between
panels, and
3) silicone gasket molded to fit the interior surface of the mullion body. While the mullion
cap, seals and glass keep most of the water from entering the system, the next two layers
channel any remaining moisture to weep holes along the lower edge of each façade.

Even standing water caught at
the lower vertex of each
diamond is addressed by tooling
a slight ramp in the sealant
joints of adjacent mullions
allowing for the water’s release.
To verify these measures

actually worked as designed, a
portion of the building was built
at full scale and forced to
undergo extreme weather
testing in controlled conditions.

L Integral to the design development of the curtain wall was the
PERFORMANCE
envelope’s thermal performance. Except for the roof, louvers, and
exposed concrete foundation walls, the exterior envelope is
comprised entirely of vision glass. This posed a considerable
THERMA
challenge to the design team given the current energy codes and
required thermal properties the curtain wall system would need to
achieve. The entire envelope, including all of its component parts,
was considered in the energy calculations. To help meet the
required performance level, approximately half of the insulated
glazing panels were fabricated with airspaces containing krypton
gas and newly developed high performance low-E coatings. In

addition, to combat increased solar heat gain experienced during
the summer months, an aluminum expanded metal mesh
interlayer was chosen for the glass panels receiving the most sun.
The mesh’s mini-louvers provide shielding of direct sun while at
the same time providing views to the exterior through the mesh.
Not only ideal for shading, the micro diamond pattern of the metal
mesh mimics the larger diamond pattern of the curtain wall
mullions. Originally envisioned to be laminated between sheets of
glass, the metal mesh floats within a 2 mm airspace in the final
design. Clear low-iron glass is used in front of the mesh to brighten
its appearance when viewed from the exterior.

28