The challenge for Construction Specialties, Cranford, New Jersey: Develop a computerized sun-shade system to precisely track the sun, automatically opening and closing huge aluminum airfoil blades to deflect its rays.
And the challenge for Hydro Aluminum: Extruded aluminum shapes large enough to extend over the 17-ft. skylight spans, with tolerances of .006 of an inch.
Construction Specialties manufactures architectural building products, primarily in aluminum. The company is particularly known for its sophisticated louvers, sun controls and sunshades. It was no surprise when the museum designers requested their help.
The sunshades are a horizontal Venetian blind positioned on the exterior of the rook over they skylights. Each sunshade has a computer tracking system that follows the sun’s movement, automatically adjusting the airfoil blades to shield the art. The airfoils themselves are aluminum extrusions, 13 to 17 feet long.
Construction Specialties engineers completed a preliminary blade design, then called Hydro Aluminum to help perfect it. “Hydro does almost all our extrusions,” said Jerry Petz, purchasing manger at Construction Specialties. “We know what we want. They have the die expertise. It’s a very good relationship.”
Each airfoil has two extrusions that snap together to form the blade. Pieces are separated by only the thinnest hairline crack. Tolerances were critical.
“This was a particularly difficult hollow,” Petz said. “Special cross braces were designed into the hollow extrusion ribs. We needed an absolutely smooth curve, but the extrusion tended to get flat on one side because of the heavy shape. “We worked very closely with Hydro, making suggestions on what we thought would work, then leaving it up to their die department to fine-tune the design.”
Construction Specialties provided special shipping cradles to protect the blades, which were laid in as half-sections. Said Petz, “When they came to us, we snapped the pieces together, painted them and reused the cradles to protect the finished unit for shipment to the site.”
When the museum opened, all sunshades were in place, silently tracking the sun and protecting the art for future generations.
